The

Slate Roof Bible

Second Edition

Joseph C. Jenkins

Joseph Jenkins, Inc.

143 Forest Lane, Grove City, PA 16127 USA
Ph: 814-786-9085; Fax: 814-786-8209
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 The Slate Roof Bible
Second Edition – Completely Revised, Expanded and Updated

© 2003 by Joseph C. Jenkins — All rights reserved.

ISBN 0-9644258-1-5; Library of Congress Control Number: 2003096286
Second Printing, 2006 • Printed in Hong Kong

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Have you seen a slate roof glisten as the sun rounds the ridge?
Have you seen it shimmer in a splash of a sky full of stars?
Have you ever seen a close-up of slates interwoven like leaves
on a tree or the way slats of stones will seem to quiver in a creekbed,

THE
or how from a distance they can look like steps ascending into the sky,
or how they float in mid-air, the way they hang loose on their nails,
or how they make a joyful noise when they are tapped
and when rain patters like a waterfall as you lie under them…

Because the rock was here before we came and will be here
SLATE
after we leave. Our first dwelling and our last, the veins we tap,
the secrets we extract. Have you driven by a farmhouse ROOF
POEM
and noticed the roof with the year of its construction slated in,

or a chicken coop with a heart-shape or a gravestone carved

with a poem? The slate on my study in Pennsylvania is from Philip Terman
a farmhouse in New England. Would we recognize each other,
we who were protected underneath the same substance?

Consider, as you sit shaded from the sun or dry from the rain,
all that geological time, the silt depositing and collecting
and compacting-shimmying and hopping and bopping
to the geologic boogie-into what has now become your roof.

Consider all that mineralogical pressure. Consider how

it must have been created on the first day, with all the other stuff
of the earth. Consider how its origins are a mystery, like love
and death and our desire to use a material that will last

beyond our lifetimes, we of the long-term, we who have faith

in the future, we who play our minor role in the eternal drama
of the significant stone, we who want to know what our part
of forever feels like. Because each square of slate is really

a petal of flowering sediments, a small piece of earth

from within the earth. A slate roof looks like a book before
it is bound. All of the pages are written by a collaborative
effort of weather and time, Hold one slate in your hands.

It is smooth and in places wrinkled like handmade paper.

You can't see yourself in the surface but it is beautiful,
it makes any building-pigsty or majestic dome-
look like a quaint hut, a cottage in a fairy tale.

Because it is so of-the-earth it is otherworldly.

Something mysterious about the way it is always shining,
something perplexing about the way it absorbs history
and stays its place. One cannot imagine a slate roof

without farms or woods or flowers around it, someone

baking bread beneath it. In one dream we walk on slate
but we slide because it is slick like trying to stand
on water. In another we are in a burning building

but we are safe inside our walls of slate.

and when we're effaced, these pieces of hard earth
above us for a short time will be beheld by others, interlocked
like our own and offering like our own their securities,

making again their music and their light.

Philip Terman is a Professor of English at Clarion University of Pennsylvania.
He is the author of The House of Sages and Book of the Unbroken Days, both from Mammoth Books (mammothbooks.com).
He lives under a slate roof in Barkeyville, PA.
 THE SLATE ROOF BIBLE
•CONTENTS•

PART I — UNDERSTANDING SLATE ROOFS

Foreword: Death and Rebirth of a Barn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2

1. Understanding Slate Roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2. From Rock to Roof — What is Slate? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
3. Identifying Roof Slate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
4. Wales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
5. Vermont — New York . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57
6. Pennsylvania Slate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
7. Peach Bottom Slate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
8. Virginia and Georgia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
9. Maine and Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
10. International Slate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

PART II — INSTALLING SLATE ROOFS

Foreword: What’s It Like to Work on a Slate Roof? . . . . . . . . . . . . . . . . . . . . . 117

11. Safety First . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119
12. Basic Tools and Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
13. Installing Slate Roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
14. Traditional European Slating Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177
15. Roof Inscriptions and Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191
16. Recycling Slate Roofs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203

PART III — REPAIRING AND RESTORING SLATE ROOFS

17. Repairs and Restoration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211

18. Flashings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
19. Chimneys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249
20. Valleys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 267
21. Tile Roofs, Asbestos, Flat Lock Copper and Misc. Roofs and Accessories . . . . 283

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .293
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .294
Industry Resource Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .295
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .311

Opposite page: Stone roof (not slate) in northern Italy. Photo by author.

The Slate Roof Bible 1

 DEATH OF A BARN

I
watched a hundred-year-old barn burn to the ground one day. As the crackling flames shot in the air
and rapidly engulfed the old building, a large raccoon suddenly appeared on the ridge of the roof. The
raccoon had been roused from its daytime sleep in the hayloft by the smoke and flames and shouts of
the firemen, and had quickly scampered up the oak barn beams to find a safe place to hide. As the flames spread
and the heat grew more intense, the raccoon began to suspect that it had made a wrong move and started pac-
ing nervously back and forth along the ridge. Those of us on the ground who were gaping at the spectacle were
horrified by the thought that the raccoon was about to become broiled alive, right before our eyes. The firefighters
tried to knock the animal off the roof using the spray of the firehose, but the raccoon, not as dumb as it appeared,
simply dodged the water by ducking behind the roof ridge. Soon the situation grew unbearable for the animal as
the flames licked over the barn roof, and the raccoon, in an obvious act of desperation, suddenly made a swan
dive off the gable end into a clump of bushes forty feet below. It looked like a suicide dive to me, but the animal
surprised everyone by bouncing off the ground with a thud, then running away. Perhaps raccoons, like cats, have
nine lives. Not true for barns.
In this case, the owner wanted the old, hand-hewn barn destroyed and had called the fire department to
burn it down. Why? It was, after all, a beautiful, century-old structure, a memento of the agrarian days of rural
Pennsylvania, of a time when everyone in the country had farm animals and lifestyles that centered around ani-
mal husbandry. When the barn was built just before the beginning of the 20th century, people still got together and
helped each other in their communities. They didn’t hop in a car and drive to each other’s farms, because there
weren’t any cars. There were hardly any roads, and what roads existed tended to be rough and impassable in bad
weather. There wasn’t any electricity out on the farms either. People relied on their horses for transportation, and
if the roads were too muddy for horse and buggy, they just stayed home, or they walked.
A cooperative group had raised this barn, probably the same group who got together at the local church
on Sunday to pray for good crops, or a safe birth for a young couple, or life renewed for a sick elder. On Saturdays
they congregated at the local grange, or in this very barn to plan political strategies or just to have a good time
square dancing by the light of kerosene lanterns, if not the moon.
When the barn was built, it symbolized all the hope and promise of a developing country. People were set-
tling the land, clearing the forest and planting the fields. Their survival rested upon the constructive relationships
they maintained with their neighbors and their cows, horses, sheep, pigs, goats and chickens. The barn would
house these animals, and thereby provide a livelihood for the country people whose new homesteads sprang up
in the Pennsylvania countryside like mushrooms after a rain in the years following the Civil War.
The barn bore testimony to the use of local trees for construction — the beams were wrought from white
oak, chestnut, or yellow poplar, while the siding was cut from pine or hemlock. The post and beam frame required
no nails, but was fastened together with elegant mortise and tenon joints locked into place with stout wooden pegs
called trunnels or “treenails.” The beams were shaped by hand with broad axes, adzes, and chisels. They were
cut with hand saws of various types, and drilled with breast drills, braces, bits, and augers. No power tools were
used to build this barn, which remained square and erect after a century of use. The proud builders no doubt stood
back and admired their work when the construction was completed a hundred years ago; then they communally
feasted and together celebrated their accomplishments, their communities, their country, and their lives.
The elderly widow who eventually owned this farm called me one day and asked me if I wanted the slate
roof that was on the barn. The barn had to go, she said, as it was beginning to collapse and was presenting a haz-
ard. I could have the roof if I wanted it, as well as any other parts of the barn, but I only had two weeks to get it. I
went over to the farm and inspected the barn to see if salvaging the slate was possible. Some barns are so far
gone that climbing on the roof would pose an unacceptable danger. This barn only had one corner rotted beyond
reasonable repair; the rest of it was in good condition, so I agreed to remove the slates.
Later, when I climbed on the barn roof, I saw why that bad corner had rotted: three slates were missing on
a spot that was, coincidentally, directly over a main support post. Aside from those three slates, the rest of the sea
green slate roof was in good condition. Of the 3,000 original slates on the roof, three of them, or one tenth of one
percent, had fallen off and never been replaced. The resulting hole in the roof was on the back of the barn where
it was not easily seen, and so it was ignored. The owners had allowed the rain water to leak through the roof
decade after decade until the barn was crippled, then destroyed. Three slates take about one hour to replace,
including setting up and taking down ladders. For want of one hour of professional maintenance, another hand-
hewn barn, a symbol of America’s rural heritage, died.
The barn wasn’t a complete loss, though, because the slate roof was salvaged and used on a new build-
ing. And I’m willing to bet the clever raccoon found itself a new home too, but probably not in a barn.

2 The Slate Roof Bible — Foreword

 REBIRTH OF A BARN
Not all barns are neglected and then destroyed. This century-old barn near Zelienople, PA, suffered storm
damage to its original side-lapped slate roof. The oak barn was structurally sound, however, and a new Vermont
“sea green” slate roof was installed in the more durable standard-lap method.The slates have been removed (top,
left) and the wide spaces between the existing oak boards are being filled with one-inch-thick rough-sawn hem-
lock lumber. Orion Jenkins and Brent Ulisky put the finishing touches on the lightning rod re-installations (top right).
Below is the newly slated barn and the slaters who installed it, with a view from the rear (center photo).
Photos by author.

The Slate Roof Bible — Foreword 3

 Chapter One

UNDERSTANDING SLATE ROOFS

“Beneath the moss covering the roof of the rugged Saxon Chapel, erected during the eighth century, at Bradford-on-Avon in
Wiltshire, England, is a slate shingle roof in good condition after twelve centuries of exposure to the elements in one of the most severe
climates in the world, a monument to the enduring qualities of slate.” H.O. Eisenberg

S
late roofs are the world’s finest roofs. hard and soft. If you have hard slates, they should
They’re fireproof, waterproof, natural, last the life of your house and you won’t need to
will last centuries, and have a track replace them. If you have soft slates, then you may
record that goes back thousands of years and spans not have a choice — you may have to replace the
the entire Earth. They are beautiful, simple roofs roof. I can tell at a glance what kind of slate you have
made of rock on wood — ingenious, effective, and and whether the roof needs replaced or not.”
fabulously successful. Yet, in the United States, they The next day I stopped to look at the roof.
have been under intense and relentless attack for The slates were hard Vermont “sea green” slates with
decades, destroyed by the thousands, cast away and a general life expectancy of 150 or more years. The
forgotten. The culprit, in a word, is ignorance. The house was about eighty years old. There was one
following conversation illustrates this point: slate missing from the roof — one slate! — and the
The telephone rang. “Hello,” a lady said, roof had a small leak at the spot where the slate had
“Are you the guy who buys used roof slate?” broken off. Otherwise, the roof was beautiful. So I
“Yes.” offered to repair the roof for a small fee, explaining
“Well, I have enough for a whole roof, and that the roof should never have to be replaced in her
you can have them all if you want them.” lifetime. The lady accepted, I did the hour-long
“Where are they?” repair job, she saved both her roof and several thou-
“They’re on my house!” sand dollars, and I haven’t seen her since. This is a
“They’re still on your roof?” true and typical story.
“Yes! And you can have them for nothing if I can go on and on with these kinds of sto-
you’ll take them off.” ries. One young lady who had a beautiful old
I paused for a moment, then asked, “Why do Victorian house with a hard, Vermont slate roof in
you want your slate roof taken off?” very good condition told me she was also consider-
“Because it leaks. We’ve already bought ing having the slates taken off the roof. “Why?” I
fiberglass shingles to replace the roof; they’re sitting asked. “Well, I thought you were just supposed to
in the driveway. We just need somebody to take the replace slate roofs when they got old,” she replied.
old roof off.” We were standing in her front yard when she said
“Well, ma’am, the reason I buy roof slate is that. The summer sun was glistening off her stone
because I repair and restore slate roofs professional- roof. Her impeccable white house stood like a majes-
ly. Maybe I should have a look at your roof before tic tribute to a time gone by when things were built
you take it off.” with quality in mind — built to last. The roof had
There was a pause at the other end of the been cared for by her father, a spry 85-year-old man
line. I could almost hear the thoughts racing who recognized something of value when he saw it.
through the lady’s head: What? I can repair my slate Now the daughter owned the house and her first
roof? thought was to rip off the slate roof, which didn’t
“But we already bought the shingles.” even leak. I stared at the house, at the perfectly good,
“You can return them and get your money hard slate roof, wondering how many thousands of
back if you don’t need them, which you may not. dollars it would cost her to remove her stone roof
What kind of slates do you have on your roof?” and put on a cheap, artificial roof. I tried to imagine
“What kind? I didn’t know there were differ- how temporary asphalt shingles would look on that
ent kinds.” proud home.
“Slates generally fall into two categories— “No, you don’t have to replace slate roofs
Opposite Page: Castle near Mayen, Germany with German slate roof.
Photo by author.

The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs 5

s This 1860 roof in Fair Haven, Vermont, was 143 years old when photographed — still in good condition. The roof is made
of Vermont purple slate with a Vermont green slate inscription. The 1862 roof located in western Vermont is also made from
Vermont unfading green slate lettering on a purple Vermont slate roof, 141 years old at the time of photographing and still
going strong. These roofs are built of stone (slate) nailed to a board roof deck — a roofing system easily replicable today. Slate
shingles on a wood board roof deck is a tried and proven water-tight roofing system guaranteed to last centuries.
Photos by author.

when they get old,” I finally said. “If the slate is internationally recognized as the best slate in the
hard, like yours is, you can expect it to last as long as world.”
your house lasts. It will certainly last your lifetime, The man was in a hurry, though, and he did-
and probably your children’s.” n’t seem to hear what I was saying. He had to call
“Really!?” someone else about removing the roof (since I wasn’t
Recently, a man called me about the roof on interested). End of conversation. End of roof.
his church. He said he had good, hard, black Then there was the guy who had the beauti-
Pennsylvania “Peach Bottom” slate on the church ful Peach Bottom slate roof on his old Victorian
roof, which is some of the best slate in the world, but house. Some Peach Bottom slate that’s 250 years old
he thought it should be replaced. Why? Because the is still good, and no one knows how long it can last.
valleys and flashings (metal joints) on the roof had Four hundred years is a fair estimate. This fellow
deteriorated and were leaking. decided to have a professional roofing contractor
“Well, replace the metal!” I advised. But my look at his 90-year-old roof and estimate its remain-
advice went in one ear and flew out the other as the ing life. He was careful to find the oldest, most
man explained to me how much it would cost to established roofer in the city. The roofer had only to
replace the entire roof with new slates. take one look at the roof to state with certainty the
“We’ll have about $150,000 to $200,000 in number of years the roof had left: “Ten,” he
replacing that roof,” he said. announced, with the air and authority of a profes-
“Don’t replace the whole slate roof, just sional. And of course that declaration was followed
replace what needs to be replaced,” I replied. “It’s not by the next, obvious one: “You’ll have to tear it off.
that hard to replace roof metal. By keeping the slate Would you like me to give you an estimate?” The
but replacing the flashing you’ll cut your costs to a homeowner was cautious and intelligent enough not
fraction of what you’re talking about. Probably down to take the contractor up on the offer. Instead he
to less than 10%. The Peach Bottom slates you have saved his roof by repairing it at a fraction of the cost
on your church might last another hundred years. of replacement, and he’ll never have to put another
Why take them off? It’s a lot of work to take off a roof on that big old house as long as he lives.
slate roof, and it doesn’t make a whole lot of sense to Otherwise, if the slate had been removed, he would
do so when the slate is still good. Besides, you can’t have been destined to replace the roof about every
even get Peach Bottom slate anymore — it hasn’t twenty years at increasing cost. Which, by the way, is
been quarried in decades, even though it was once what many roofing contractors live for.

6 The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs

s A picture is worth a thousand words. Photographed by the s Barn near Townville, PA, in poor repair. Main roof is Lehigh-
author in 2002, this roof, covered with Vermont purple slate Northampton (black PA) slate; designs are made of Vermont green
with a Vermont unfading green inscription, was 151 years old slate. Inscription reads, “L. Jones - 1902.”
at the time and still quite functional. In contrast, the average Photos by author.
American asphalt roof looks rather unpleasant and only lasts
between 15 and 20 years. You just can’t beat a good slate
roof for beauty, utility, or even cost — when the entire life
span of the roof is taken into consideration.

Slate roofs originated in Europe, and some installations). Most of the nails on these roofs are
of the earliest Europeans to develop a proficiency in still good. In fact, they’re so good that I could use
slate quarrying and slate roofing were the Welsh. some of them over again on a new roof. Even after a
Slate roofs are common in Europe where they’re val- century! And 99% of these nails are hot-dipped gal-
ued enough that some are still in good repair after vanized or cut steel, not copper. A photo of these old
several centuries. It is against cultural mores to nails can be found in Chapter 13.
replace a slate roof with an asphalt roof in Europe, In some cases, on some parts of roofs, espe-
and the people there are so adamant about it that cially leaking and neglected roofs, nails can and do
they have passed laws preventing people from go bad. This is especially true when the wrong nails
replacing slate roofs with cheap substitutes. There were used in the first place, which happens, but not
are photos of European slate roofs in this book to very often. As a rule, bad nails are rarely a reason to
help illustrate the contrast between American values replace a slate roof. If the nails are going bad, it’s
and European values. There, they know a good thing either because the slates themselves are going bad,
when they see it. Here, we rip off our slate roofs at meaning they’re worn out soft slates, or the wrong
the first sign of a leak and replace them with substi- nails were used when the roof was installed.
tutes that are miserable by comparison. If you own a However, in Europe, when a roof goes bad because of
slate roof, you will likely hear every conceivable rusting nails or rotting wood underlayment, the
excuse to tear it off. The strongest urging may come slates are simply removed, the wood replaced, and
from contractors who stand to gain financially from then the same slates, or new slates, can be nailed to
the destruction of your stone roof. the roof with new nails. A slate roof can be kept alive
I hear it all. One common myth is that slate for centuries in this manner.
roofs have to be replaced because their nails go bad. Another dubious reason to want to replace a
Usually, this is not true. At the time of this writing, slate roof is because the roof paper or underlayment
I personally have worked on well over 1,000 slate (the felt underneath the slate) has deteriorated.
roofs over the past 35 years. Old slate roofs. That After a hundred years, or less, the roofing felt paper
means I’ve climbed on a thousand slate roofs, torn turns to dust. People peer through the gaps in the
them apart and put them back together, examined roof boards in their attics and see that the paper has
them, assessed them, removed and recycled them, turned to dust, and they conclude, “Time to replace
repaired, restored and installed them. Their average the roof!” Wrong! Roofing felt paper is not a necessary
age has been about 100 years (not counting the new part of a slate roof. It is typically used as a temporary

The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs 7

cover to protect the building in the event of rain the life of their house, and could last hundreds of
until the finished roof is installed. Roof paper does years, nobody really knows. Purple Vermont slates
help temporarily to insulate the roof, but its useful- that have seen a century of wear look pretty much
ness in shedding water is greatly reduced when the same as new purple Vermont slates, so who
thousands of holes are poked through the paper as knows how long they’ll last? I told them it would
the slates are nailed on. Barns typically do not have cost a few hundred dollars to do the routine mainte-
any roof paper under their slates, and they’re as nance on their 90-year-old roof, as opposed to ten
waterproof as any other slate roof, even after a cen- times as much to replace the slate with asphalt shin-
tury. It is foolish to think that the paper underneath gles that were guaranteed to quickly fail. The lady
the slate is an important part of the roof. It is not. was adamant about not liking the color, though, and
But believe me, there are hordes of Cro-Magnon I sensed that this roof was doomed. “If you do decide
types out there who will bend over backward to con- to remove the roof,” I offered, “I’d be willing to
vince you otherwise. remove the slates free of charge, for salvage purpos-
Then there’s the curtain theory. One middle- es.”
aged couple called me to look at their roof. They “Well, we’ll call,” they said. A month or two
were considering removing it and replacing it with later I drove by the house. A brand new, brown
fiberglass shingles — so-called "premium" asphalt asphalt shingle roof sat on top of the home. I knew
shingles that are guaranteed to fail in twenty years, what happened to the beautiful slates—they were
after which they curl up like potato chips and blow carelessly destroyed by the roofers who tore them
away in the wind. Anyway, I stood out in front of the off. I have seen it many times—the roof slates are
house looking at the beautiful, decoratively-cut rudely ripped off, thrown on the ground, hauled off
Vermont purple slate roof, one of the best slate roofs in the back of a dump truck, and unceremoniously
a house can have, with the homeowners standing by dumped in a landfill. The homeowners are several
my side. thousand dollars poorer, they’ve permanently lost
“That’s where it leaks,” said the lady as she their wonderful slate roof, and now they’re faced
pointed to a section of roof on the front of the house with having to replace the cheap asphalt roof every
where a Neanderthal had applied tar. twenty years at a constantly increasing cost. But the
“Not hard to fix,” I replied, then I walked roof matched the curtains! At least I think it did—I
around the house to get a good look at the rest of the didn’t notice the curtains—who ever does?
roof. I could tell that the husband wanted to keep Every now and then I see a slate roof where
the slate roof, but the wife didn’t. Every now and one side of the roof has been replaced with asphalt
then I’d overhear bits of conversation as they contin- or fiberglass shingles. Picture this if you can: you’re
ued to stand out in their front yard gesturing toward balancing on the ridge of the roof and to one side of
the house. the ridge you see a slate roof, the other side a shin-
“The slate roof doesn’t match our new cur- gle roof. The shingle roof is curling up and falling
tains!” apart, worn thin, brittle and leaking. The slate roof,
“I know, dear.” already 90 years old, looks nearly the same as it did
“We need a brown roof if we’re going to when first installed, and exactly the same as it did
match the curtains.” when the shingle roof was installed 20 years ago. You
“I know, dear.” wonder why the homeowner ever took the slate off
When I returned to the couple, I briefly the one side in the first place. Now look into the
explained to them that their purple slates would last future: the decrepit shingle roof will soon be

OLD ROOFING MATERIAL IS FILLING UP LANDFILL SPACE

When old roofing is removed from buildings, it is trucked to landfills. Non-biodegradable, petrochemical roofing
made of asphalt and fiberglass typically lasts about 20 years, then is discarded. Roofs such as these that are
guaranteed (by the manufacturer) to fail in two decades, are guaranteed to clog landfills year after year.
According to scientific studies, construction and demolition debris make up 28% of the weight and 28% of the
volume of the mixed waste in landfills, and is much more significant to landfill management policy than
Styrofoam, fast-food packaging, disposable diapers and the total of all plastic packaging combined!
About one fifth of all construction debris is roofing waste. Environmental concern is only one reason to
have a slate roof, but it’s an important one.
[Source: Garbage Magazine, Mar/Apr 1992, p. 67, and Jul/Aug 1992, pp. 20-21]

8 The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs

replaced and the slate roof will, once again, be left roofs, they charge an exorbitant fee, knowing that if
alone. In another 20 years the same scene will repeat they get paid enough, they’ll do the work. So if a
itself. Then again. Then again. Each time, the shin- homeowner can find someone to fix the slate roof,
gle roof will need to be completely replaced — the old and if she can afford him, then she will probably still
shingles hauled to a landfill, if there is any landfill have to pay to have the job done wrong! Which means
space left by then, and the homeowner will needlessly she’ll have to pay again to eventually have the job
fork out more money to eager roofing contractors. done right, and re-doing someone else’s lousy work
The slate side, if left alone, and repaired is always harder than doing the job right in the first
occasionally as needed, will smugly sit there, stone place. This makes for a frustrating situation for own-
quiet, stoically oblivious to the vagaries and vicissi- ers of slate roofs, and it’s one of the main reasons
tudes of the human race. It will continue to do what this book was written.
it’s supposed to be doing: protecting the dwelling I recently met a contractor who advertised
and sheltering the people who live there. And it will himself as a specialist in slate roof repair, and who
do so with a level of aesthetics and a richness of his- told me he goes through about 15,000 pieces of slate
tory that a fiberglass shingle couldn’t hold a candle every year doing roof repairs. Then he proudly
to. The folly of replacing such a roof with a cheap informed me with a grin and a nod, “I face-nail every
substitute becomes clearly evident when one roof one of ‘em.” What roof owners don’t know is that
displays both roofing materials at the same time, every face-nailed slate (nailed through the face of
and their performance can be seen and compared the slate so that the nail-head remains exposed to
side by side. the weather after the repair is completed) is an
A common reason why people feel they need improperly installed slate, one that will leak, and
to remove their slate roofs is because “We can’t find one that has been ruined by the roofer who punc-
anyone to fix our roof.” If they do find someone, they tured it. So here’s a guy whose roofing company
run the risk of hiring a contractor who wants to face-nails fifteen thousand slates every year. Every
“gouge” them (i.e. charge a small fortune for repair- single one of those ruined slates will have to be taken
ing the roof). Most contractors don’t specialize in off and replaced someday. Before they do, though,
slate, or even roofing, and when they’re not building they’ll probably leak. This roofer gets paid good
decks or installing bathrooms, they’ll “repair” your money to slowly destroy people’s slate roofs. And
roof. Most of the contractors I’ve met who repair I’m not singling him out intentionally. He’s typical!
slate roofs do it improperly. And because they’re not (Although he’s since gone out of business.)
equipped and experienced to work on high, steep Why do contractors face-nail slates? Because

From the Slate News Bulletin, May, 1926

The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs 9

 THE BURNING OF THE “MYSTERY HOUSE”
Though staged primarily to prove the fire-resisting qualities of certain building materials, the “Mystery House” of
Indianapolis was an advertising feature that aroused public curiosity, attention and approval. The house was built by
Williams Creek Development Company for the purpose of a fire test. The house was a two-story building made of fire-
proofed material and roofed with slate.
To provide a severe test, the lower floor was filled with kindling and lumber scraps saturated with kerosene. The oil-
saturated wood, highly combustible, was ignited, and for three quarters of an hour (until the fire was extinguished) the build-
ing confined the flames like a huge furnace. To extinguish the flames, the fire department deluged the building within and
without. A careful and critical examination after this severe treatment showed the slate roof intact without a single slate
cracked from the fire and water. Publicity of the test was heightened by the presence of the mayor and the city fire chief of
Indianapolis. The mayor started the fire and the chief put it out.

they don’t know any better, and/or because it’s a lit- telling the truth. Ask him where your slates came
tle bit easier and quicker than doing it the right way. from and how long they’ll last; ask him to explain
Some contractors focus more on how much money how he replaces a single slate; ask to see his slate
they’re making than on how well they’re doing the cutter, slate hammer, slate ripper and ladder hooks.
job. There are instances when face-nailing is appro- You may know a lot more about your slate roof than
priate, but they’re few and far between. We’ll get he does by the time you’ve read through this book,
into all of that when we cover slate roof repairs and and if the guy is an imposter, you’ll know that, too!
restoration step-by-step in the third part of this There are numerous reasons why old slate
book. roofs should be preserved, in addition to longevity.
If you don’t want to fix your roof yourself, One is aesthetics. In this plastic world a stone roof is
but do want to hire a competent contractor, make a symbol of durability, of quality and craftsmanship.
sure the contractor you hire is either experienced Once slate roofs become old they fall into the catego-
with slate or has read this book before he’s set a foot ry of antique roofs, plain and simple. They’re rich in
on your roof! If your contractor tries to tell you he history. Imagine the human effort and struggle that
already knows everything there is to know about enabled people to bring many tons of massively
repairing or installing slate roofs (a common line), heavy stones up from hundreds of feet underground,
then ask him a few questions to see whether he’s split them into shingles by hand, and do it all in the

10 The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs

 Official inspection of the “Mystery House” after the fire

horse and buggy days, before electricity was avail- THE NEANDERTHAL SYNDROME
able. People will give their eye teeth for a hundred-
year-old chest of drawers, yet they’ll discard at whim The Neanderthal Syndrome was discovered
a perfectly useful, irreplaceable, antique stone roof by the author, who has had the opportunity to study
worth $10,000, or much more. Why? the traces of human impact left on slate roofs over
Let’s also not overlook the fact that the pur- the years, sort of like an anthropologist studying the
pose of a roof is protection. Stone roofs are fireproof campsites of cavepeople.
and withstand the elements like no other roof. If you Many times I have positioned myself atop a
live under a properly maintained stone roof, then slate roof and marveled at the utter and absolute
you know exactly what I mean. There’s no feeling folly with which the roof had been treated. I have
like the feeling of security you get when the wind is shaken my head in disbelief, theorizing in vain as to
howling and torrential rain or sleet or ice is beating
down upon the earth and pummeling your house, ROOFING CONTRACTOR
and a stone roof stands guard overhead, deflecting WARNING SIGNS:
mother nature’s blows. Living under a stone roof is 1) Receding forehead
kind of like living in a cave. It’s almost a primal 2) Arms hang down to
experience, and with a little imagination, we can see knees
3) Excessively hairy
why such a roofing material appeals to us instinc- knuckles
tively. There is no shelter quite as secure from the 4) Tools look suspi-
ciously like a club
harsh elements as a cave, and any roof made of pure
5) Doesn’t walk upright
rock comes close to providing the same level of pro- 6) Speaks Neanderthal
tection as the earth itself. fluently
7) Salivates when calculat-
Speaking of caves, it’s time to take a look at ing cost estimates
the Neanderthal Syndrome:
The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs 11
s A slate roof enhances the beauty of the lowliest building, such as the author’s chicken coop (above), as well as the grandest of castles.
t The date on this Vermont “sea green” slate roof was made by using red slate found in the Granville, NY, area.
This roof was 113 years old when photographed and, if properly cared for, will outlast the house.
Photos by author.

12 The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs

 s A Vermont “sea green” slate roof located in western Pennsylvania
with a PA black slate date, probably 1887.

(Left) This purple and green Vermont slate roof, dated 1862,
will last for generations if properly cared for, despite its age of
131 years at the time of this photo. Age does not destroy slate
roofs as quickly as improper maintenance.
Photos by author.

what could possibly have caused the prior “roofers” drove a spike into the roof wherever a slate looked
to put replacement slates in upside down and/or loose. Sometimes he’d drive a spike into the roof for
backwards, to tar an entire roof in order to cover a no apparent reason, perhaps just to look busy when
pinhole, to drive steel spikes through the slate roof the boss was around. Of course, a sixteen penny nail
willy-nilly, like a rampaging lunatic who just driven into a slate roof cannot be removed without
escaped from an insane asylum and decided, on a breaking a few slates in the process, and if it’s left in
whim, to climb up on someone’s roof and start the roof, it will leak.
pounding nails into it. No doubt I have seen every Another crew member loved tar, otherwise
imaginable assault and insult to a slate roof, much of known as roof cement or mastic, and he used it for
which is beyond human comprehension, without all his slate roof repairs. He kept a bucket in hand at
any reasonable explanation, and, at times, infuriat- all times as he spread the tar liberally over the sur-
ing enough to become a laughing matter simply for faces of the roof. If he was in a really good mood,
the sake of sanity (mine). he’d use a thin tar that he could brush on and then
The explanation is simple: Neanderthals he’d really go to town painting everything in sight. If
never became extinct, they simply evolved into roof- a roof had a tiny hole in it, he would tar the whole
ing contractors. The traces of their work are on thing. No pinhole was going to get the better of him!
almost every old American slate roof I have ever Such legendary roofers worked on slate roofs
seen. I call these traces “Neanderthal tracks.” for decades, and it’s speculated that they grew old
It appears that there was once a one-armed, and died, but I’m not so sure about that. They might
blind roofer. The slates he used to replace broken still be out there working away, reincarnated as
slates didn’t match the roof at all. When he repaired younger Neanderthals. Ironically, these guys are
a nice green roof, he used black slate. When he slowly putting themselves out of business, because
repaired a black roof, he used green slate. When he they deface and destroy slate roofs to the extent that
replaced square slate, he used slates with cut cor- the roof owners can’t stand their own roofs anymore.
ners. Nothing matched and it all looked bad when When a slate roof has so many metal patches, tar
he was done, but it didn’t bother this fellow — he blotches and leaks that never stop, it looks ugly, gets
was blind! frustrating and drives the roof owner to throw up his
He had a crew who each had his own style of hands and shout, “Tear the damn thing off!”
roof “repair.” This crew must have worked very hard Fortunately, virtually any Neanderthal track
for many years because their work can be found can be erased, no matter how bad or how hopeless
across the United States. One of the hardest workers the roof looks to the roof owner (see Chapter 17).
kept his nail bag full of 3½-inch-long spikes, and he There is one exception to this rule. Old slate

The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs 13

 tury or more of wear, in order to help ascertain the
longevity of the slates from each region. Museums
and libraries were scoured for historical information
in order to understand the conditions and tech-
niques involved in producing the slates still gracing
older homes and buildings today. Personal inter-
views with quarry workers, roofers (there are some
good ones, by the way), architects, homeowners and
other history buffs, along with a multitude of pho-
tos, added to the investigation.
Not content only with information about
American slate, the author journeyed to northern
Quebec and on to the far coastal reaches of
Newfoundland, Canada, then across the Atlantic
Ocean to Ireland, Wales, Scotland, England, France,
Germany, Spain and Italy, looking at slate roofs, hik-
ing through slate quarries, descending into slate
mines, and gathering information from slate distrib-
The above Peach Bottom slate gravestone, a scant one inch thick, is utors, slate roofing masters, slate geologists, and
dated 1743. The inscription is not worn at all after 250 years of expo-
sure to the elements. It reads, “Here lys y body of Jamer Roger who
anyone else who had something to say about stone
departed this life Novembry 9, 1743 aged 33 years.” This stone bears roofs.
testimony to the longevity of slate from the Peach Bottom, The information gathered during these voy-
Pennsylvania/Maryland slate region.
Photo taken by the author at the Chestnut Level Cemetery, Quarryville, PA.
ages, combined with decades of on-the-job experi-
ence and observation, have led to the creation of this
much-needed book. I, the author, will be the first to
roofs that are made of the softer (“S2”) slates cannot admit that there are many different opinions about
be restored. Soft slate will flake, crumble and fall slate roofs, many ways to install them, numerous
apart sometime between 55 and 125 years. If the roof ways to repair, restore, appraise, assess and evaluate
slate is otherwise hard, the roof can usually be them — some quite sound, but others quite mistak-
restored and may still last for generations, even if en.
it’s already a century old. If the slate is old and soft, Let the reader be warned that there is a
it may still last for years, but will need to be replaced strong trend in U. S. roofing these days to largely
before long. Of course, any worn out slate roof abandon traditional roofing styles, methods and
should be replaced with new or recycled roofing materials in exchange for those that are convenient,
slate. expeditious and cheap. You will find that a gross
Unquestionably, historic slate roofs can have lack of understanding about slate roofs is firmly
an air of mystery about them. The men who installed entrenched at the highest levels of the roofing
them have long since died and the old roofs (in the trades, with misinformation running rampant. Not
United States in particular) have been virtually only roofers, but also architects can be notoriously
ignored by almost everyone since. The origins of bad sources of information. Luckily, slate roof sys-
these old roofs and their remaining longevity and tems are incredibly simple, and when their simplic-
value are difficult to determine for laypeople and ity is understood and respected, these roofs are also
professionals alike. unbelievably successful.
The author of this book, a professional slate For an on-going discussion on slate roofing
roofing contractor and consultant, set out on a quest with the latest information about tools, techniques,
determined to clear up this confusion. In a ten year sources of materials, supplies, and even contractors,
process, he located the original sources of various visit the author’s web site at jenkinsslate.com.
old American roof slates and visited the actual quar-
ry sites, which range from Georgia, up the eastern
seaboard of the U.S. through Virginia, Maryland,
Pennsylvania, Vermont, New Jersey, New York and
Maine. Old roofs at each American quarry site were
examined to determine their conditions after a cen-
14 The Slate Roof Bible — Chapter 1 — Understanding Slate Roofs
 Chapter Two
FROM ROCK TO ROOF – WHAT IS SLATE?
“Slate tombs high in the Alps near Oisans, France (which, from money and jewels found in them, archeologists
have concluded were constructed about 500 B.C.), are still in good condition.” Oliver Bowles

or heave vertically, or even turn upside down in the

I
t will help to understand slate roofs if earth.
one first understands what slate is. Yes, it This geologic pressure forced the material to
is a rock, it comes from the ground, undergo fundamental changes in its chemical com-
sometimes it’s black, sometimes it isn’t. Most peo- position, eventually to become what we now call
ple, believe it or not, don’t even know that much. A slate, made up primarily of mica in the form of fine
newspaper reporter once did a story on a local slate flakes arranged in parallel order. Mica is a generic
roof restoration business, and the first thing she term for any group of minerals that crystallizes in
asked was, “What’s a slate roof?” The roofer replied, thin, easily separated layers. In slate, the mineral is
“You are joking, aren’t you?” and she said, “No, I’ve primarily silicon dioxide, often in the form of crys-
never seen a slate roof. I didn’t know there was such talline quartz.
a thing.” “Next time you drive through town look The age of slate ranges from Cambrian (from
up,” he replied. “The slate roofs are the ones made the word Cambria, which is a name for Wales) a time
of stone. They usually have a sheen to them, they 600 million years ago when life dawned on earth and
look natural, they tend to be on older homes, you the first abundant marine life appeared, to Silurian
can’t miss them. There are thousands of them right (another Welsh name), a time 425 million years ago
in our small town, and millions throughout the when mountains were forming in Europe and the
United States and the world.” first small land plants appeared.
For those of you who want to know more Slate is a finely layered stone that can be eas-
than that about slate roofs, let’s start with some fun- ily split, somewhat like a deck of cards. If you lay a
damentals. There are three kinds of slate: mica, clay deck of cards on a table, then “cut the deck,” it’s
and igneous. Mica slate is the only kind we’re con- obvious that it can be split in two horizontal halves
cerned with because that’s what roof slates are made quite readily. However, if you try to split the deck in
from. two halves vertically, forget it. The horizontal layer-
Mica slate is considered to have formed from ing of the deck lengthwise, or of the slate, constitutes
clay-containing silts originally deposited under the cleavage plane of the slate, as it is the plane on
water in horizontal beds, such as on the floor of which the slate readily splits. This plane is deter-
ancient river beds or seas. These clay sediments mined not by the sedimentary layering of the slate
compacted over many millions of years under the over the eons as one would expect (that’s the bedding
pressure of sedimentary deposits above them so that plane), but by the geological forces that squeezed the
the final clay content became very small through clay deposits together. The cleavage plane may be
metamorphosis. Some beds were subjected to hori- entirely independent of the bedding plane, which is,
zontal geologic forces which caused the beds to fold, by definition, a distinct peculiarity of slate. Some

MINERAL COMPOSITION OF AVERAGE SLATE Mineral% Vermont NY PA VA

Quartz . . . . . . .59-68 . . . . . .56-68 . . . . . . .55-65 . . . . .54-62
Quartz . . . . . . . . . 31-45 %
Al2O3 . . . . . . . .14-19 . . . . . .10-13 . . . . . . .15-22 . . . . .17-25
Mica (sericite) . . . . 38-40 % Fe2O3 . . . . . . .0.8-5.2 . . . . .1.5-5.6 . . . . . .1.4-4.5 . . . .7.0-7.
Chlorite . . . . . . . . . 6-18 % FeO . . . . . . . . .2.5-6.8 . . . . .1.2-3.8 . . . . . .2.3-9.0 . . . .
Hematite . . . . . . . . 3-6 % CaO . . . . . . . . .0.3-2.2 . . . . .0.1-5.1 . . . . . .0.2-4.2 . . . .0.4-1.9
Rutile ......... 1-1.5 % MgO . . . . . . . . .2.2-3.4 . . . . .3.2-6.4 . . . . . .1.5-3.8 . . . .1.5-3.9
Mica is here also known as secondary muscovite, or white K2O . . . . . . . . .3.5-5.5 . . . . .2.8-4.4 . . . . . .1.1-3.7 . . . .
mica, chemically composed of potash and aluminum. Na2O . . . . . . . .1.1-1.9 . . . . .0.2-0.8 . . . . . .0.5-3.5 . . . .
Chlorite is a mica-like mineral usually containing aluminum, CO2 . . . . . . . . .0.1-3.0 . . . . .0-7.4 . . . . . . .1.6-3.7 . . . .0.2-2.0
iron and/or magnesium. [Source: Bowles, The Stone Industries, 1934] US Dept. of Commerce, Bureau of Standards, Journal of Research, V9, No.3, 9/32

The Slate Roof Bible — Chapter 2 — From Rock to Roof 15

roof slates have darker or lighter bands, known as parting along numerous, close-spaced and parallel planes
ribbons, running across their face showing where the that bear no relation to bedding; this is true ‘cleavage’
bedding plane was intersected when the slate was and the use of the term should be restricted to this feature.
split along the cleavage plane. The term has also been applied to a tendency to part
Slate can also be split along the grain, on a along small, joint-like openings, more closely spaced than
plane perpendicular to the cleavage plane. The joints, but less so than true cleavage planes, and general-
“grain” of the slate is very important when quarry- ly inclined to the cleavage; this may be called ‘false cleav-
ing, as roofing slate is usually split so that the longer age’. A third set of fracture planes of which no trace is
sides of the roofing slates are in the direction of the visible to the naked eye until the slate is actually broken
grain. This helps to reduce breakage. Or, as one and which is generally at right angles to the true cleav-
writer put it, “In splitting and dressing the roofing slate, age, is the ‘grain’, ‘sculp’ or ‘scallop’ of quarrymen. The
it is always done so that the grain runs parallel to the cleavage plane in slate is the direction of easiest parting
longer side of the rectangle. This grain, although never so and is due chiefly to the arrangement of the individual
marked as that in the timber, has a similar effect upon the crystals in the rock.” [Slate in Pennsylvania, p. 29]
strength in different directions [Peach Bottom Roofing
Slate, 1898].” I vote we leave the splitting of the slate to the
Slate can also be split across the grain, by professional quarrymen. Generally, though, you get
drilling a hole in the block of slate and wedging a the picture (I hope).
“plug and feathers” into the hole, forcing the block Slate is, as we were saying, a very dense,
to pop in two (don’t try this on a deck of cards). heavy, finely grained rock, with an average particle
All of this, obviously, can be quite confusing size of 0.1 to 0.01 millimeters. This fine particle size
to someone not familiar with quarry geology. If you aids slate in its ability to be perfectly split, and this
would like your eyeballs to glass over further with cleavability of slate gives it its practical value. A true
incomprehension, then read the following industry slate can be split into thin sheets with smooth, even
definitions: surfaces. Some slates can be split as thin as one thir-
ty-second of an inch. In the manufacture of black-
“The term ‘cleavage’ has been applied to three board slate, a 4’x6’ piece can be split to a uniform
different structures in slate. It has been used to designate thickness of three-eighths inch or one-half inch,
depending on the slate source.
A scientific theory first published in 1912 by
German meteorologist Alfred Wegener stated that
all of the earth’s land masses were once joined
together as a single land mass, called “Pangaea.”
Pangaea is theorized to have split apart approxi-
mately 300 million years ago into two continents,
one of which eventually became Africa and Europe,
while another became the Americas and Asia. The
basis for this theory is apparent when one looks at
maps of the continents today and sees how they
seem to fit together, as if they’ve broken apart from
each other. Interestingly, the slate deposits that run
up the east coast of the US, across the eastern edge
of Canada and into Wales evidently formed before
Pangaea broke apart, when Europe and the
Americas were still joined. This is why Canadian
and Welsh slate are nearly chemically identical,
despite the fact that they’re separated by thousands
of miles of Atlantic Ocean. They’re also both very
similar to Vermont slate, which is not far from
Canada.
Since slate formed from sedimentary
An illustration of grain, cleavage, splitting and sculping. deposits, an ancient river or an inland sea must have
[Source: Levine, Jeffrey S., 1993, The Repair, Replacement, and Maintenance of Historic Slate Roofs]
existed on Pangaea where we now have slate beds.
16 The Slate Roof Bible — Chapter 2 — From Rock to Roof
 Greenland

Canada Wales
Russia
Europe
USA
Slate deposits

Continental Drift
Africa

SLATE DEPOSITS AND CONTINENTAL DRIFT The slate found from the southeastern United States, up the eastern US
seaboard through New England, eastern Canada and in Wales and Europe, formed in the Earth before the continents broke apart. It is
these slate deposits that have been worked into roofing material for American homes. However, slate has also been imported into the
U.S. from places such as Austria, Belgium, Czechoslovakia, Germany, Gibraltar, Japan, Netherlands, Sweden, India, Switzerland, Italy,
France, Norway, China, Portugal, Australia, Luxemburg, South Africa, Spain, England, Argentina, Brazil and Bali.
[Listing of imports from “Slate in 1929,” by Bowles and Coons, Mineral Resources, 1929, Part II, Page 166, U.S. Dept. of Commerce, Bureau of Mines,]

RATING THE DURABILITY OF ROOF SLATE

The American Standards of Testing and Materials (ASTM), first organized in 1898, is a non-
profit organization which writes standards for materials, products, systems and services.
ASTM C406-00 provides standards for roofing slate, distinguishing between S1, S2 and S3
slate according to the criteria below. S1 slate rates a service life in excess of 75 years, S2
is rated for 40-75 years, and S3 is rated 20-40 years. In reality, hard slate (S1 slate) may
last 400 years, while S2 (soft) slate may last considerably longer than 75 years.
Modulus of Maximum Depth
Rupture Across Maximum of Softening
the Grain, min. PSI Absorption % inches (mm)
Grade S1 . . . . . . . . 9,000 . . . . . . . 0.25 0.002 (0.05)
Grade S2 . . . . . . . . 8,000 . . . . . . . 0.35 0.008 (0.20)
Grade S3 . . . . . . . . 7,000 . . . . . . . 0.45 0.014 (0.36)

C406-00 Standard Specification for Roofing Slate, Developed by Subcommittee: C18.03; Adoptions:
Building Codes; Book of Standards Volume: 04.07; C121-90(1999) Standard Test Method for Water
Absorption of Slate; C120-00 Standard Test Methods of Flexure Testing of Slate (Modulus of Rupture, Device used to measure strength and
Modulus of Elasticity); C217-94(1999) Standard Test Method for Weather Resistance of Slate; American elasticity of slate.
Society for Testing and Materials (ASTM), 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959; (Source: U. S. Bureau of Standards Journal of
TEL (610) 832-9585; FAX (610) 832-9555 ; www.astm.org Research, Vol. 9, No. 3, September 1932, p. 385)

A Rather Boring Definition of Slate

The American Standards of Testing and Materials has

adopted the following formal definition of slate:

Slate is a micro granular crystalline stone derived

from argillaceous sediments by regional metamor-
phism, and characterized by a perfect cleavage
entirely independent of original bedding, which cleav-
age has been induced by pressure within the earth.

sA block of slate showing bedding ribbon, cleavage and

grain planes.
[From Slate in Pennsylvania, p. 29]

The Slate Roof Bible — Chapter 2 — From Rock to Roof 17

 A T I M E L I N E : H O W O L D I S S L A T E ?

700 million 600 500 400 300 200 100

years ago

Peach Bottom Most Pennsylvania Pangaea (earth’s single Brontosaurus First human Today
slates formed slates formed continent) breaks apart ancestors

Slate is so old it boggles the mind. Humans weren’t even a

gleam in Mother Nature’s eye when the minerals that
ERA OF SLATE FORMATION make up slate were deposited in thin layers by settling
to the bottom of ancient seas or river beds. Imagine
that you’re standing at the end of a time line and the time line extends behind you like a string.
Imagine that 10,000 years pass in one foot of the string’s length, so that a mere 12 inches
behind you is a point in time 10,000 years in the past. If you go back 60 feet, you find
North America covered by glaciers. If you go back a mile, you find the earth’s major
mountain ranges, the Rockies, Andes, Alps and Himalayas, forming. If you go back
five miles, you find Pangaea, the earth’s single continent, breaking apart. You will
have to go back almost twelve miles to find slate forming. If this seems like an
unbelievably long time ago, imagine this: the known age of the earth
would take us back 85 miles!
Slate predates the Brontosaurus by several hundred million years!

Pennsylvania Ribbon Slate

If a ribbon is a band containing a high amount of carbon, it will deteriorate
much more quickly than the rest of the slate, causing the piece of roof
slate eventually to break into two pieces. This diagram is showing a rib-
bon crossing the slate above the nail holes.
When the ribbon deteriorates, the slate will
not fall off the roof because the nails will
hold it in place. The slate may still leak
though, as the soft, crumbly ribbon will
allow a place for water to penetrate. If the
ribbon is below the nails, the slate will
eventually break in two and the bottom will
fall out.The ribbon may be difficult to see
unless one knows what to look for. Some
black PA slate roofs are made of ribbon
slate, and can’t be restored when old. A rib-
bon slate may last 50 to 100 or more years,
depending on its place of origin. Some
slates, such as Chapman slates, have hard
ribbons that do not deteriorate prematurely.

AVERAGE ABSORPTION OF SLATE

After 48 Hours Immersion in Water

Monson, Maine: . . . . . . . . . . . . . . . . . . . . . . .0.05%

Vermont-New York: . . . . . . . . . . . . . . . . . . . . .0.13%
Buckingham, VA: . . . . . . . . . . . . . . . . . . . . . . .0.06%
Eastern Pennsylvania
Bangor: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.28%
Pen Argyl: . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.30%
Hard Vein: . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.16%
Wind Gap: . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.38%
Slatington: . . . . . . . . . . . . . . . . . . . . . . . . . . . .0.29%

The top three varieties of roof slate have a much lower absorption factor
and have also proven to last much longer on roofs than the slates listed
below that have high absorption factors. This indicates that the less
water a slate will absorb, the longer it will last. (Source: Bureau of Standards
Journal of Research, Vol. 9, No. 3, p. 397, September 1932)

18 The Slate Roof Bible — Chapter 2 — From Rock to Roof

When one considers that the slate deposits in east- thin layers, each representing a period of time so far
ern Pennsylvania are about a half mile thick, and in the distant past as to be quite unfathomable to us
that slate is an intensely compressed material, then short-lived humans. So as quarrymen dig down
one can speculate that an immensely deep body of through the slate, they come upon layer after layer
water must have existed for eons and collected silt with different characteristics, some softer, some
for many millennia of Earth’s time. This scenario harder, some useless rock.
becomes even more fascinating when one under- For example, in the Pen Argyl region of east-
stands that during the time of earlier slate forma- ern Pennsylvania, one of the world’s most prolific
tion, no animal or plant life existed on Earth, as the sources of black slate, the layering of the slate is par-
planet was too young, and life in the seas was just ticularly evident. Beginning with the topmost beds,
beginning to blossom. This may explain why fossils slate runs appear in the following succession:
are only very rarely found in slate deposits — the Pennsylvania Run, United States Run, Diamond Run,
only fossils the author has seen in slate (from Albion Run, Acme Run and Phoenix Run, each run
Germany) were Cambrian Trilobites. bearing a slate of somewhat different quality. The
Due to unknown reasons, the slate that runs aren’t in direct contact with each other but are
formed on Pangaea developed different characteris- separated by intervening beds 75 to 280 feet thick of
tics depending on the location of the slate bed. For unworkable slate-like rock.
example, the slate in Wales has many color varieties, Each run is itself then separated into indi-
including black, purple, blue and green. Purple and vidual beds. The Albion Run, for example, consists of
green slate are also abundant in Newfoundland, 12 beds combined together to form a total run thick-
Canada. Continue south into Maine and you find a ness of 184 feet. Some of the beds are “big beds,”
black slate, but carry on a little farther into Vermont some are “ribbon” slate, and some are unworkable
and New York and the slate is either purple, green, rock. The Albion Gray bed is known for its excep-
gray, red or black, and may be streaked, mottled or tionally high quality.
layered with iron-containing minerals that change Some slate deposits have thin (one or two-
color with exposure to the weather. Travel a bit fur- inch) layers of minerals that will leave a visible strip
ther south again into eastern Pennsylvania and you across the finished roof slate. You may see green
find huge deposits of black slate, but a few miles fur- streaks across purple slate, and various colored
ther south in Chapman, PA, the black slate contains streaks or mottled spots on different slate varieties.
gray bands. Down in Maryland you find both a black Normally, these do no harm but instead add some
and a purple slate that were once quarried there, but color and character to the slate. However, the most
continue into Virginia and the slate is black again, notorious “ribbons” occur in some black
and on close examination contains a sparkly quartz Pennsylvania slates, where an almost invisible band
that glistens in the sunlight. Black, red and green of gray/black material, high in carbon content,
slate deposits exist in Arkansas; both green slate and leaves a vulnerable spot in the slate. As carbon dete-
black slate can be found in Georgia, and green slate riorates more readily than the more common slate
in Tennessee. minerals such as quartz and mica, these ribbons will
The period of slate formation ranged from turn soft over time and the slate will then break
600 million years ago or more, to approximately 450 apart. A carbon ribbon such as is common in
million years ago, which allows for a span of about Pennsylvania ribbon slate will turn soft enough over
150 million years during which slate was formed. time (50 - 100 years) that you will be able to push
One hundred fifty million years is too long to com- your finger through it.
prehend, but if sedimentary deposits occurred over Other types of slate, most notably the
millions of years, one can understand why slate Vermont “sea green” that is so common in the U.S.,
would vary not only according to the location of the change colors with exposure to the weather. The
slate in the earth’s sub-surface, but also according to result is an interesting mottled red and gray appear-
the depth level of the slate in the thick layers of the ance which the roof develops over the years. This
beds. In eastern Pennsylvania, the main commercial phenomenon is known as the “weathering” or “fad-
slate deposits are 2,800 feet thick, thirty miles long ing” of roofing slate by people in the slate industry.
and two to five miles wide. That’s a big chunk of Many people have “sea green” slates on their roofs,
solid slate lying just below the surface of the earth. also known as “semi-weathering gray-green” slate, as
2,800 feet thick means more than a half mile thick these slate deposits were abundant, easy to work,
layer of slate, and in that half mile are billions of high quality and therefore popular for roofing.
The Slate Roof Bible — Chapter 2 — From Rock to Roof 19
 Slates that are harder to work because, for may even measure weaker. After many years of expo-
example, the grain is not straight or uniform enough sure to the seasons, some slate will deteriorate more
or the slate is too hard and brittle, will not be so rapidly than other slate, regardless of how strong the
widespread on roofs. The same goes for slate that is slate is when new. So the longevity of slate cannot be
found only in small deposits. judged by the apparent hardness of the slate when
Many people say, “I didn’t realize that there newly quarried, and instead, a variety of factors are
were so many different kinds of slate. I thought all considered.
slate was the same!” As you can now see, all slate is The U.S. slate industry uses several highly
not the same. In our younger years, the only slate we technical standards to determine the strength, elas-
may have been aware of was the slate blackboard, ticity (bendability), abrasive hardness, toughness,
and unless we grew up in a slate quarrying area, we acid resistance and porosity of slate. A variety of
may have developed the idea that all slate is black. contraptions may be used to determine these meas-
Instead, we actually have a great variety of slate with urements, thereby allowing for the slate to be catego-
a great variety of qualities, colors and characteris- rized according to expected durability.
tics. Roofs have been covered with all types of slate, One indication of the potential durability of
as well as other stone. Some black slate from Italy slate on a roof is the absorption characteristics of the
even turns white with exposure to the weather! slate. Some slate absorbs more water than others,
One of the most important things to ascer- although no slate absorbs very much. The chart on
tain about any slate roof is what type of slate is on the page 18 shows some average absorption levels for
roof, because then you will know how long the roof various roofing slates after immersion in water for
should last. We’ll look at how to identify the slate on 48 hours. Those slates that have a very low absorp-
individual roofs in the next chapter of this book. tion ability have proven to have a very high rooftop
longevity.
DETERMINING THE QUALITY To simplify the complicated process of rat-
OF ROOFING SLATE ing the durability of slate, the industry has adopted
a rating scale which rates slate as S1, S2 and S3. This
We have established that some slate is hard- rating scale combines various factors pertinent to
er, some softer, depending on such factors as geolog- the longevity of the slate such as acid resistance,
ical age, the degree of metamorphosis and the min- strength and ability to absorb water. Slates that have
eral composition. For the sake of simplicity, soft a high acid resistance, low water absorption and
slate is here being generally defined as slate that more high strength are listed as S1 slate, which is consid-
readily softens with prolonged exposure to the weather, ered the best slate to use for roofing. Generally
while hard slate is slate that resists softening and stays speaking, these are the “hard” slates to which we
hard with prolonged exposure to the weather. Hard slate have been referring — the roofing slates that will
will obviously outlast soft slate on a roof. last several human lifetimes, and perhaps several
I have seen soft slate (Pennsylvania ribbon centuries, on a roof.
slate) that had to be replaced in 55 years, and I have S2 slates are not as acid resistant as S1 slate,
seen hard slate 250 years old (Pennsylvania Peach and they absorb slightly more water than S1 slate,
Bottom slate) that had no apparent deterioration. I and although they are not expected to last as long on
keep a piece of hard “stone slate” in my shop that I a roof as S1 slate, they can still make an excellent
brought back from a 16th century abbey in Wales, an roofing material. Much of the S2 slate found on
original piece, which shows virtually no wear. It had roofs today originated in eastern PA in Lehigh and
been hung on the roof by a single wooden peg, two Northampton Counties, and appear as black slate, or
inches long and the thickness of a pencil. The peg brownish-black slate (also called “blue-black,” and
had been driven through a hole in the stone and gray slates). These are the most common “soft”
hooked on a thin piece of roof lath, which was the slates in the US, and they may last only as long as 50
way Welsh slate was originally installed. years, or maybe as long as 150 years, depending on
Measurements of slates from various regions the place of origin. Many original soft slate roofs
of the United States show that the strength of a slate have already deteriorated beyond repair and have
when newly quarried is not necessarily an indication been replaced, and many more will be replaced in
of how long it will last on a roof. Some slates that last the next few decades. Although soft slates don’t last
much longer than others will not measure much as long as hard slates, they’ll still outlast just about
stronger than the others when newly quarried, and any other roofing material on the market and are
20 The Slate Roof Bible — Chapter 2 — From Rock to Roof
well worth buying for roofing material. “sea green” or semi-weathering green or gray green
Soft slates appear crumbly or flaky when old slates from Vermont, are the weathering or “fading”
and will give a dull thud when tapped with a ham- type of slates. If these slates were to be rejected out-
mer, while hard slates will appear smooth and will of-hand as they may be in Europe, the world would
ring when tapped. But some hard slates will appear a be deprived of an incredibly valuable resource with
little flaky too after a century or so, particularly the loss of millions of beautiful roofs. Roofs that
some varieties of sea green slates. In addition, change color with age are not bad roofs and many
although many black slates are soft, some of the most people even prefer them for their unusual character,
durable roof slates in the world are black. So it is oblivious to the unreasonable rejection of these sorts
important to try to pinpoint the exact place of origin of roofing slates in some roofing/architectural cir-
of the slates on old roofs in order to understand their cles. Some Europeans also turn their noses up at roof
qualities and to judge the remaining life expectancy slates that contain a high carbonate content, such as
of the roof. the Italian slates that start out black and turn white
Despite the ASTM testing standards that with exposure to the weather. The local Italian peo-
allow a slate to be rated S1, S2 or S3, this rating sys- ple who mine these slates and use them for roofing
tem has generated a lot of controversy in the slate have learned that they make charming and long last-
roofing industry and may be abandoned in the ing roofs, despite the carbonate content, by simply
future for a more accurate system. It seems that a splitting the slates thicker and installing them with
single piece of roofing slate, when divided into four increased headlap.
equal pieces and each piece tested separately, can The truest test of a roofing slate is the test of
yield four different test results, even when tested by time. Most existing types of roofing slates have a his-
the same laboratory! This problem seems to cause torical element that can be observed and measured,
quite a bit of consternation among slate quarriers. although this has never been considered a measure-
This rating system is further undermined by the fact ment of quality by the testing laboratories. Perhaps,
that any slate producer can simply provide the in the future, roof slate varieties will be judged
results of their very best test score even if it’s twenty according to their historical record of performance
years old and came from a piece of slate from a sec- as well as according to mechanical or chemical labo-
tion of the quarry no longer being worked. In short, ratory test results. In the meantime, we can observe
the ASTM S1-S3 ratings may not be the most reli- century-old slate roofs and see how well they have
able way to determine the quality of a piece of slate. held up, if we want the truest indication of the
To add to the confusion, in Europe, for longevity of any particular type of roof slate.
example, a slate may be poorly rated if it is consid-
ered “fading,” which means it changes color with
age. However, some of the best slates in the United
States, and probably the most popular, namely the

The Slate Roof Bible — Chapter 2 — From Rock to Roof 21

22 The Slate Roof Bible — Chapter 2 — From Rock to Roof
s Stone roofs in northern Italy are made of rock taken from nearby mountains, pointed out by the roofer doing the installation.
Although this rock is not slate, it creates a roof with inimitable character and longevity, nevertheless. The worker (opposite)
drills the stone in preparation for nailing in place. A single large nail fastens the massive stone to the roof.
Photos by author.

The Slate Roof Bible — Chapter 2 — From Rock to Roof 23

 Chapter Three
IDENTIFYING ROOF SLATE
(Understanding What’s Overhead)

(use a pair of pliers and break a small piece off an

I
n order to understand an existing edge of the roof if you have to). It may also be help-
American slate roof and its historical ful to remove a slate from the roof and look at the
significance, as well as its expected back side if the front is tarred.
remaining longevity and overall value, one must In any case, you can look at a slate till you’re
first identify the type of slate on the roof. That sim- blue in the face, but if you don’t know what to look
ply means one must determine where the slate was for, it won’t do you a bit of good. On the next page is
quarried. Slate varies significantly from quarry to a map of the eastern seaboard of the United States
quarry and from slate region to slate region. In gen- indicating the five main slate producing regions.
eral, slate can be expected to last from 55 years to There’s nearly a 100% chance that older American
centuries on a roof in the United States, depending roof slates came from one of these regions.
on the type of slate. Some slates may last significant- Otherwise, the slates may have been imported from
ly longer if made from a high grade of slate rock and a foreign source. This is not likely on older roofs,
split thicker than the standard 3/16”. Some of the except on very expensive establishments or perhaps
better grades of slate rock can be expected to last 200 at very old historic coastal sites where slate may
years even at 3/16” thickness. have been brought over as ballast in ocean-going
A good slate roofer can tell what type of slate vessels. There are a few other areas of the United
you have at a glance, but you’ll have to figure this States that have produced quantities of roof slate,
out on your own if an experienced slater is not read- and if you live near one of them, you may have that
ily available. Don’t be disappointed if you can’t find type of slate on your roof.
anyone to identify the slate on your roof. Remember For those who live in any of the main slate
that the men who installed the old slate roofs are producing regions, your identification problems are
almost all dead and gone, and most younger roofers more than likely solved. If you live near Monson,
today can’t be bothered with trying to find out where Maine, you can be pretty certain you have Maine
roof slate came from, especially as most of them slate on your roof. Same goes for Peach Bottom,
don’t work on slate roofs anyway. Vermont-New York, Buckingham and Eastern
The easiest way to identify roof slate is visu- Pennsylvania. In visiting all of these slate quarrying
ally. Look at the color and smoothness. Next, handle regions I wasn’t surprised to see that in each region
the slate, break it apart and judge its strength and they used their own slate on their own roofs. If you
density. Old soft slate may almost fall apart in your don’t live in any of these regions and have a slate
hands and will be visibly flaking. Hard slate, on the roof, then you’ll have to familiarize yourself with the
other hand, generally remains smooth on the surface types of slate each region produces.
and stays hard, even after a century of wear. Let’s start at the beginning: slate has several
After breaking open a piece of slate, look at basic colors — namely black, “blue-black,” gray,
its interior. The interior of the slate is the same color purple, green, “sea green” and red. You know what
as when it was originally quarried. The exterior of black looks like (like a blackboard), although some
some slate changes color over time with exposure to black slates turn brownish with age, and some devel-
weather or pollution, making it hard to identify the op white overtones; blue-black looks black with a
slate with certainty without breaking a piece open. slight hint of blue; green slate does have a greenish
Some slate roofs have been completely tarred over tint to it when quarried, but often turns light gray
by well-meaning but misguided roofers and the only with age; sea green looks blue-green when quarried,
way to identify these slates is by breaking one open but turns light gray and develops mottled hues of

Opposite page: A mix of Vermont slates has created a beautiful, rounded valley on a graduated slate roof in Grove City, Pennsylvania.
Photo by author.

The Slate Roof Bible — Chapter 3 — Identifying Roof Slate 25

 WHERE DO AMERICAN ROOF SLATES COME FROM?
e = Inactive roof slate production today
r = Active roof slate production today
MONSON, MAINE
All regions were active at the time most
older American roofs were installed. e

VERMONT - NY

s VT purple slates with a sea green band and NY red slate flo-
rets. t PA black slates and VT unfading green slates at 120
years. The black is getting soft, the green is still hard. Photos by author.

r
PEACH BOTTOM e

r
There are five main roof slate producing regions in the United States, all
on the eastern seaboard. Only three of these regions are producing roof
slate today, although there are many slate roofs still in existence bearing
slates from all regions. The regions that are no longer producing roof
slates have not stopped because they’ve run out of slate. Quite the con-
trary, the quantity of slate that has been removed from the earth has so
far, in all regions, only scratched the surface of the immense deposits.
Roof slate production has stopped in the Monson, Maine region and the
Peach Bottom, Pennsylvania region due to economic factors: the roof
slates have simply become too expensive to produce.

The graph at left

shows which states
in the U.S. used the
most roofing slates
in 1929 (group 1),
and which used the
least (group 7). This
s PA black slates that are just about worn out. t VT sea green
provides a rough
slates that have weathered brown due to the quarry of origin
estimate of where
and/or to environmental conditions. Roof is still quite good.
the majority of
American slate
roofs are located
today. Note that the
GROUP 1: Delaware, District of Columbia, Maryland, southern states
New Jersey, New York, Pennsylvania, West Virginia seem to have the
GROUP 2: Connecticut, Maine, Massachusetts, New least number of
Hampshire, Rhode Island, Vermont slate roofs. This
GROUP 3: Illinois, Indiana, Michigan, Ohio may be due to the
GROUP 4: Alabama, Kentucky, Louisiana, Mississippi, heat of the south,
Tennessee which can be
GROUP 5: Arkansas, Iowa, Kansas, Minnesota, absorbed by the
Missouri, Nebraska, Oklahoma, Texas, Wisconsin stone roofs, or to a
GROUP 6: Arizona, California, Colorado, Idaho, lack of proximity to
Montana, Nevada, New Mexico, North Dakota, prolific quarries.
Oregon, South Dakota, Utah, Washington, Wyoming [Source: Bowles, (1930),
GROUP 7: Florida, Georgia, North Carolina, South Slate in 1929].
Carolina, Virginia

26 The Slate Roof Bible — Chapter 3 — Identifying Roof Slate

The Smithsonian Institution Building, known as the “Castle,” is covered in a mix of fairly new and also recycled Buckingham, Virginia slates.
Photo by author.

red, tan, pink or orange (depending on your eye- be expected to last between 150 to 200 years, or
sight) with age; purple slate is dark purple when longer. These slates are still being quarried and are
quarried and stays that way with age, but may look readily available commercially.
black or dark gray to an untrained eye (some purple EASTERN PENNSYLVANIA: Black, blue-
slates have green streaks in them, variegated purple black, dark gray and various other shades of black.
has lots of green streaks); red slate is red like terra Virtually all of the soft slates come from this region,
cotta ceramic tile, and stays red with age; gray slate with lifespans of as little as 50 years or less, although
is somewhat light gray when quarried, may have some of the black and gray slate from this area can
black streaks, and retains its original color with age. be quite long-lasting (100-150 years). There is a con-
The industry term for slate that changes color with siderable variety of blackish slate from this region,
age and weather is “fading” or “weathering” slate, including CHAPMAN slate (a striated, durable
and slate that does not change color is called “unfad- black slate), and “Cathedral Gray,” a lighter, durable
ing.” Each region produces colors of slate peculiar to black. “Ribbon” slate also come from here, having a
that region, as follows: carbon band across the face that can cause the slate
MONSON, MAINE: Solid black slate with to break prematurely with age.
slight luster, hard, durable. One of the best slates PEACH BOTTOM: Black slate, from the
available. May last hundreds of years. These slates Pennsylvania/Maryland border, very hard and long
are no longer quarried, so recycling old roofs is lasting. This is an excellent slate with a lifespan that
imperative. may approach 400 years, and should be preserved on
VERMONT/NEW YORK BORDER: Green, roofs, or recycled, as this region is no longer quarry-
sea green, gray, red, purple, black. Many of the col- ing roof slate. On close examination, you may see a
ored slates come from this area. Most of these slates slight sparkly luster to the slate, especially on the
are of exceptional quality and very durable and can back (unweathered) side.
The Slate Roof Bible — Chapter 3 — Identifying Roof Slate 27
Note: Roof slate is a natural material and will vary from sample to sample in color and character. Slate samples are available from the quar-
ries and suppliers listed in the back of this book in the “Quick Reference” section. Acquire a sample to accurately determine the color.

“UNFADING SLATE”
Natural slate comes in many colors, including
black, gray, purple, green, “sea green,” red and oth-
ers. The industry term for slate that changes color
with age and weather is “fading” or “weathering”
slate. Roof slate that does not change color, or only
changes minimally, is called “unfading,” and is often
regarded as a higher quality slate within the indus-
try. Common types of American slate include
“unfading green,” “unfading purple,” “semi-weather-
ing gray-green” or “sea green,” and “unfading red.”
Most commercial Spanish slates are unfading black
(some are green). German roofing slate is also
unfading black, as is French roofing slate. Canada,
like Wales, produces unfading black roofing slate
(Quebec) as well as both unfading green and purple
slates (Newfoundland). China produces many col-
ors of roofing slates and their unfading black slate
is gaining popularity throughout the world. Don’t be
fooled by the hype, however, as some of the weath-
ering slates — sea green, for example — are among
the best slates in the world.

Left: Unfading red slate from eastern New York on

a church in Foxburg, Pennsylvania. Photo by author.

28 The Slate Roof Bible — Chapter 3 — Identifying Roof Slate

 [Canadian slate was quarried in Quebec, near Kingsbury (north of Vermont), and is quarried now at St.
Mark de Lac Long, Quebec (north of Maine), and at Burgoyne’s Cove in Newfoundland.

LOCATION OF KNOWN SLATE DEPOSITS IN THE UNITED STATES

Solid marks are (or were) productive districts, hollow marks are prospective districts. The five commercially important
U.S. roofing slate districts are: 1) Monson District, Maine; 2) New York/Vermont border; 3) eastern Pennsylvania;
4) Peach Bottom (PA/MD border); 5) Buckingham District, Virginia, although only #2, #3 and #5 are still productive.

MAINE: Monson, Brownsville, North Blanchard. Solid black slate with slight luster, (hard, durable).
VERMONT/NEW YORK BORDER: Rutland County, VT (Poultney, Fair Haven, Wells, East Poultney) and Washington
County, NY (Granville). Green, sea green, gray, red and purple slates (hard, durable).
EASTERN PENNSYLVANIA: Lehigh and Northampton Counties (Bangor, Pen Argyl, Chapman, Slatington, etc.) Black,
blue-black, dark gray, other shades of black (ranging from soft to moderately hard).
PEACH BOTTOM, PA/MD: York/Lancaster Counties, PA and Harford County, MD. Black slate (hard and long lasting).
BUCKINGHAM, VA: Buckingham County (Arvonia). Black slate (very hard and durable).
NEW JERSEY: Sussex Co. (Lafayette). Black, same slate as easternmost PA
GEORGIA: Polk County (Rockmart), and Bartow County (near Fairmount). Greenish gray hard slate south of
Fairmount; bluish gray (black) slate at Rockmart (ranges from hard to somewhat soft).
TENNESSEE: Monroe County (Tellico Plains). Purplish, greenish and black slate (hard).
MINNESOTA: Baraga County (Arvon). Black slate (quality uncertain).
UTAH: Slate Canyon. Green and purple slates (quality uncertain).
ARKANSAS: Montgomery County near Norman and Slatington. Red and green slate, and some greenish gray and
black slate near Mena, Polk County (quality uncertain).
CALIFORNIA: Eldorado County, near Kelsey. Dark gray slate resembling PA slate in color (quality uncertain).
NORTH CAROLINA: Quality and type uncertain.

Note: The original reference materials included no descriptive information for the States shown on the map that were not listed above.
[From a 1914 map by T. Nelson Dale for the U. S. Geological Survey, Bulletin 586, Plate 1; North Carolina data from Moebs, Noel N., and Marshall, Thomas E.,; 1986; Geotechnology
in Slate Quarry Operations, USDI, Bureau of Mines RI 9009]

Roofing slate is also presently quarried or mined in many places throughout the globe, most notably Spain (world’s
largest producer), China, Germany, France, Italy, Argentina, Wales, England, South Africa, India, Norway and elsewhere.

In general, slate can be expected to last from 55 years to hundreds of years on a roof in
the United States, depending on the type of slate, roof construction, and proper mainte-
nance. Slate type is determined by where the slate was originally quarried.

The Slate Roof Bible — Chapter 3 — Identifying Roof Slate 29

 QUICK REFERENCE — IDENTIFYING OLDER NORTH AMERICAN ROOF SLATES

BLACK OR DARK GRAY SLATE

MAINE (Monson area), hard, dark black, smooth sheen; may last centuries; not available new today; highly recyclable material and
therefore the roofs are highly restorable.
VIRGINIA (Buckingham County), hard, “blue black,” light to dark gray; may show striations; characterized by sparkly sheen best viewed in
sunlight; 135 year life expectancy or longer; recyclable; available new today.
GEORGIA, dark gray to black; 75-125 year life expectancy or more; no longer quarried; may show surface flaking when old.
PENNSYLVANIA
LEHIGH/NORTHAMPTON DISTRICT, various black to dark gray shades; may be flaky and crumbly or rusty or brownish on sur-
face or have whitish edges when old; wide variation in longevity from 50 years to 150+ years; still available today.
PEACH BOTTOM DISTRICT, hard, dark black, smooth, not flaky on exposed surface; no longer available new; highly recycla-
ble; best varieties may last hundreds of years.
VERMONT, “Vermont black” slates, may show striations; some Vermont black slates are softer than others; 100+ years; still quarried.
CANADA, Glendyne quarry (northern Quebec), 100+ years; still quarried; slates from southern Quebec similar to PA Lehigh Northampton
slates.
COLORED SLATES:
VERMONT, Green (various shades), “sea green,” purple (various shades), variegated and mottled purple, also light gray; all are smooth,
hard, long lasting slates, the best of which may easily last 200+ years; all still quarried today; highly recyclable.
NEW YORK (on Vermont border), the only source of brick red slates; smooth, hard, no flaking, very long lasting; still quarried today; highly
recyclable.
CANADA (Newfoundland), both purple and green slates are quarried here; smooth, hard; very long lasting; still available today.

BUCKINGHAM: Gray-black or blue-black could very likely last the life of the building it’s on
slate, very hard and durable, can last centuries. — such roofs should practically never have to be
Similar to Peach Bottom, shows many tiny sparkling replaced. On the other hand, if the roof is made of
specks in sunlight on close examination, especially the softer, eastern Pennsylvania slate, it may have
on back where air pollution hasn’t stained the sur- reached the end of its life (after a century) and no
face. amount of work, money or prayer will save it. The
Air pollution causes slate to change color with roof will have to be replaced whether you like it or
age. Lots of slates are hard to identify simply not (although many older Pennsylvania slate roofs
because of the neighborhood the roofs are in. Smoke may have decades of life left in them). When soft
from coal stoves or from local factories will cause the slate roofs are replaced, by the way, they should
roof to develop a peculiar hue which may turn a always be replaced with slate roofs (not asphalt shin-
black slate lighter gray, or a green slate brown, or a gles), and Pennsylvania black slate is an excellent
red slate black. There’s no way to predict this, so in choice if someone wants a roof that will last a long
these situations you’ll have to resort to breaking time.
open a slate and looking inside to identify the color. In any case, it’s important to know how to
Remember, the color inside the slate indicates the identify the slate on a roof because when the roof is
color at the time of quarrying. Add to this the fact restored or repaired, matching slates should be used
that some slate turns color on the surface with age, to do the restoration work. In cases where the origi-
and then may undergo another color change due to nal color of the slate is totally obscured by environ-
air pollution, and you can see why visual identifica- mental conditions and therefore cannot be matched
tion can be tricky at times. Furthermore, some black with any replacement slates, then a relatively invisi-
slates from eastern PA will exude a chalk that turns ble section of the original roof must be “cannibal-
them somewhat white (usually around the edges), ized” in order to provide suitable repair slates. The
while other black slates from the same region will cannibalized section is then reslated with a slightly
weather to a brownish hue. different roofing slate. In subsequent chapters we’ll
To add to the confusion, overhanging trees look at each of the slate regions in greater detail, as
change the color of a slate roof. Leaf drop from an well as at restoration techniques, so if you’re con-
overhanging tree will stain slates, making them a fused about the different types of slate roofs, there’s
darker color. Also, slate is readily stained to a very still hope!
dark brown by rusting metal, such as rusting ridge But first, we should look at how and why
iron or flashing. slate was discovered and quarried in the United
Why is it so important that we identify the States, and in order to do that we must take a trip to
slate on old roofs? Well, if the roof has Monson, Wales.
Vermont/New York, Peach Bottom or Buckingham
slate on it, then it’s highly restorable and the slate

30 The Slate Roof Bible — Chapter 3 — Identifying Roof Slate

s Vermont “unfading green” slate roof on the Zimmerman House at the Delaware Water Gap National Recreation Area is 120 years old at the
time of the photograph, and the slates themselves are in phenomenally good condition. The flashings need some work, however.
t Chapman, Pennsylvania, black slate showing its characteristic diagonal ribbons across the face of the slate. This slate can last about 100-
120 years if properly maintained. Read more about this slate in the Chapman section of this book.
Photos by author.

The Slate Roof Bible — Chapter 3 — Identifying Roof Slate 31

 s A mix of New York red slate with Vermont purple and Vermont sea green random-width slates gives this roof a beauti-
ful and unique character. t An ornate Vermont sea green slate pattern in a background of either black Pennsylvania or
Virginia slate creates a monumental roof that will last for generations if properly maintained.

Peach Bottom slate is shown on opposite page, top, on the Stevenson United Methodist Church in Maryland, eighty-eight
years old. Roof on opposite page, bottom, is Ford’s Theater in Washington, DC. The slates that are visible in the photo
are the 135-year-old original Buckingham, Virginia slates. Much of the remaining roof had been replaced with new
Buckingham slate.

Photos by author.

32 The Slate Roof Bible — Chapter 3 — Identifying Roof Slate

The Slate Roof Bible — Chapter 3 — Identifying Roof Slate 33
 Chapter Four
WALES
“In 1980, a small boat, loaded to the gunwales with slate, was discovered at the bottom of the Menai
Straits. It has been dated at 1270, and, although no one can be certain, the slates appear to have come from
the Penrhyn Quarries at Bethesda, North Wales.”
John Brigden

A
study of slate quarries and the phe-
nomenon of the slate industry in
the United States must start in
Wales. In order to gain a deeper and more thorough
understanding of slate roofing, we should take a look WALES
at the men and women, the times and the places that
started it all for us Americans. In doing so, we shall
understand that slate quarrying in America and the
use of slate for roofing were not new endeavors
brought to fruition by pioneering, resourceful peo-
ple in a new country. They were instead ancient
skills wrought from the knowledge of a timeless peo-
ple — a people who endured lengthy sea voyages to
carry their mastery of stone work across the vast
Atlantic Ocean to a new land of hope and promise.
And with their proud trades they brought proud tra-
ditions: the Welsh language, church and customs. In
essence, they brought Wales itself, carving out small
enclaves in America that seemed very much like
their former home.
The mountainous country of Wales is locat- Phillips, Powell, Jenkins, Griffith, Richards,
ed along the western edge of England and measures Morgan, Humphries, Edwards, Davies, Hopkins and
136 miles in length, varying from 37 to 92 miles in others. Granted, slate is not the only reason the
width. North Wales is home to Mt. Snowden, the Welsh emigrated to the United States. They were
highest mountain in England and Wales, a rugged, also master tin platers, coal miners and iron work-
snow-capped mountain which practically casts its ers. However, their expertise in slate dates back cen-
shadow over the largest slate quarries ever worked. turies.
These quarries are laden with immense slate The most important slate regions in Wales
deposits yielding some of the best purple, green and are in the ancient kingdom of Gwynedd (pro-
black slate in the world. nounced “Gwineth” — the Welsh “dd” is pro-
Pangaea broke apart hundreds of millions of nounced like the English “th”), including
years ago, shifting the earth’s crust eons before the Snowdonia in North Wales, the home of Mt.
earliest evolutionary beginnings of the human Snowdon which rises 3,560 feet above the Irish Sea
species. That separation of the planetary surface left to the northwest. There are also fourteen other peaks
a link between Europe and the United States in the rising over 3,000 feet in this area, making it a rugged
form of underground slate deposits that would even- territory where the removal of tons of stone was not
tually draw the Welsh people to the new land of just a challenge, but a feat. This harsh terrain in
America, and in so doing, influence the ethnic and North Wales is particularly notable when one con-
cultural development of a country we now call home. siders the primitive transportation systems available
“Keeping up with the Jones’s” is a common until recent times, and the poor conditions of the
American saying, and Jones is a Welsh name. So is roads (or lack of roads) in the nineteenth century,
Thomas, Roberts, Evans, Hughes, Lewis, Williams, when most of the slate was removed.

Opposite page: Entrance to the now abandoned Vivian Slate Quarry near Llanberis, Wales. Photo by author.

The Slate Roof Bible — Chapter 4 — Wales 35

 NORTH WALES
CAERNARVON AND NEARBY QUARRY AREAS

Bangor
Caernarvon

Blaenau
Ffestiniog Penrhyn Quarry
Dinorwic Quarry
Dorothea Quarry

Llechwedd Quarry
Blaenau Ffestiniog
Ffestiniog

Merionethshire

Up until the end of the 1700s, sledges with-

out wheels were used to transport goods throughout “Valeys bryngeth forth food, And hills metal right good,
the area, and in 1798, Reverend Richard Warner Col groweth under lond, And grass above at the hond,
described them as having “the shape similar to the There lyme is copious, And sclattes also for hous.”
body of a waggon, capable of containing two or three
hundred weight of peat.” These sledges were drawn by The word “slate” comes from the Middle
a Welsh pony, a small beast of burden owned by English “slat” or “sclate.” After around 1630, usage
almost every cottager. of the latter version became exclusively northern or
North Wales was also geographically isolated Scottish. The word is related to the French word
from both England and South Wales by marshland, “esclater” which means to break into pieces, and
moorland, estuaries and the Severn River. Or, as one refers to the cleaving characteristic of the rock.
quarry manager put it, “[South Wales] is a foreign Therefore, in the verse we just read, the last line
country as far as the North Walian is concerned.” The refers to the abundance of slate used for roofing as
uplands of Caernarvonshire were suitable only for well as other house construction purposes, such as
grazing sheep, or for the scenery, and visitors have walls, in Wales.
been drawn there for centuries in order to get a In Welsh, cleavable rocks such as slate can
glimpse of the magnificent countryside, which be called “llech” (the “ll” is pronounced like a gut-
boasts seaside and mountain range, green valleys tural “cl”), and the name is reflected in the name of
and quaint villages. at least one slate quarry, the “Llechwedd Quarry”
What all this all adds up to is a slate indus- near Blaenau Ffestiniog. The older Welsh name
try that, although somewhat active for centuries, did specifically referring to slate is “ysglatus,” “ysglats,”
not boom until the 1830s. Once the roads and rails or “sglatys” and dates from the fifteenth century.
were in place the industry expanded rapidly, only to One poet of the time (late 1400s) referred to Welsh
decline just as suddenly in the early 1900s. The slates as “jewels from the hillside,” and “warm slabs, as
annual output of slates in North Wales in 1832 was a crust on the timber of my house.” The cleavage of the
100,000 tons, which rose to about 450,000 tons in slate is called “hollt” in Welsh.
1882. By 1972 the output had fallen to about 22,000 Slate is located in Wales in the counties of
tons, due to market competition from ceramic tiles Caernarvon, Denbigh, Merioneth, Montgomery and
and concrete roofing materials (not from asphalt Pembroke, although the largest quarries are located
shingles, by the way, which are a cheap, temporary, in Caernarvonshire (Caernarvon County), which
petro-chemical roofing material extremely popular also is home to the slate exporting cities of
in the United States but almost unheard of in Caernarvon and Bangor. The two largest slate quar-
Europe). ries in the world are located in Caernarvonshire, and
One early description of the resources of are known as the Penrhyn Quarry and the Dinorwic
Wales dates from 1387, in the words of John Trevisa Quarry, located on opposite sides of the Elidir Fawr
as translated from Ranulf Higden: Mountain. The Penrhyn Quarry, which is still in

36 The Slate Roof Bible — Chapter 4 — Wales

 SLATE PRODUCTION IN GWYDIR QUARRIES, WALES, 1810 - 1950
Although this graph only shows the production of one small Welsh quarry (Gwydir), it follows a pattern much in line with other areas of Wales.
Note the slump in production between 1840 and 1860. It is perhaps no coincidence that much of the early immigration of quarry workers
from North Wales to the United States took place during the mid-1800s. The Gwydir slate quarry was a small quarry which produced about
7,000 tons of slate at its peak. In comparison, Wales’ largest quarry, the Penrhyn Quarry, which was responsible for the production of one
quarter of all Welsh slate, produced 130,000 tons in 1862. The Ffestiniog Quarries produced 145,000 tons in 1882.
AND IN AMERICA
Slate in America was discovered at Peach Bottom by the Welsh in 1734, and the first commercial quarry opened there in 1785. The first
slate quarry in the Lehigh-Northampton district of eastern PA opened in 1812. Owen Jones, a Welshman, discovered slate along the Lehigh
River in 1846, and slate was subsequently discovered near what is now Bangor, PA, in 1853. The Bangor Quarry was opened by a
Welshman named Robert Jones in 1863. Slate was discovered in Vermont by a Welshman in 1835, and in 1870 slate was discovered near
Monson, Maine, once again, by a Welshman.
[Graph: Williams, M. C., and Lewis, M. J. T., 1989, Gwydir Slate Quarries, Snowdonia Nat. Park Cr., Plas Tan y Bwlch, Maentwrog, Blaenau Ffestiniog, Gwynedd LL41 3YU, Wales]

production today, eventually grew into a hole a mile tant Ordovician slates in the Snowdonia region, and
long, a third of a mile wide, and 1,300 feet deep, and the deposits dip into the earth under the mountains,
out of this hole 300 million tons of slate and rock so most of the slate has been deep mined. The
have been removed, mostly by hand. The Dinorwic Llechwedd Quarry dates from 1846 and boasts of a
quarry was so large, it had as much as fifty miles of valuable “old vein” which was purported by a work-
rail track within it, covering a total area of about 700 er there to have once produced thin sheets of slate
acres, eventually leading to the removal of an entire long and pliable enough to bend into a circle,
mountaintop. although this claim is found unbelievable by
The slate in central Caernarvonshire dates American slate quarriers. The underground tunnels
from the Cambrian age (600 million years old), mak- in this mine totaled 25 miles in length, and descend-
ing it a very hard and durable material. The slate ed to 900 feet. Some of the original tunnels have
towns in this area include Bethesda (the Penrhyn been restored for historical purposes and can now be
Quarry), Llanberis (the Dinorwic Quarry) and toured on an electrically powered underground tram
Nantlle (the Dorothea Quarry). for a distance of about a half mile.
A second slate producing area exists near There are also three other commercially
Blaenau Ffestiniog in Merionethshire and in the important slate producing regions of Wales: the area
adjacent parts of Caernarvonshire. Here the slate is between Towyn and Dinas Mawddwy, the area
of Ordovician age, which, at roughly 500 million between Llangollen and Corwen, and the Presely
years old, is younger than Cambrian, although still district of Pembrokeshire. Incidentally, slate is also
very durable. A slate worker at the Llechwedd located in England in Cornwall, Devon, the Lake
Quarry once told the author that Blaenau Ffestiniog District, Aberdeenshire and Argyll (see Chapter 10
slate would last 400 years. These are the most impor- for additional information about UK slate).

The Slate Roof Bible — Chapter 4 — Wales 37

 Welsh slate can be of a variety of colors in Lloyn y bettws . . .20 shillings to me towards the slating
addition to purple, green and black, going by such of the dwelling house, and he to send the carriage of the
quaint names as silky red, hard spotted blue, royal slates and the meat of the slaters and carpenters.”
blue, curly red, old blue, red hard, hard red bronze,
purple green wrinkled, sage, willow, barred red, old It’s anyone’s guess what “meat of the slaters”
quarry blue and blue grey mottled, in the Llanberis is supposed to mean (probably their dinner) — the
area alone. The Nantlle area has a green vein, silky point, of course, being that slate roofs have been
vein, blue mottled vein, red and blue striped vein, common in Wales for centuries. Other records speak
red spotted vein and red vein. The Penrhyn area has of slate roofs in 1536-9 when John Leland stated,
green, purplish blue, grey, grey mottled, mottled and “The houses within the town of Oswestre be of tymbre
striped, and blue. The Ffestiniog area has mainly and slated,” and “they dig oute slate stones to kyver hous-
blue-grey. In Corris, Abergynolwyn and es,” and in 1597, when John Wynn’s memoranda
Aberllefenni, the slate is pale blue, and in Glyn included a note to “slate the cattle houses.” Such
Ceiriog and near Llangollen, the slate is blue. Mind records continue through the 1600s.
you that these descriptions are industry terms which In the late 1500s slate was being exported to
tend to describe black as “blue,” and the slates they Ireland from Wales — about 100,000 were exported
describe as red and blue striped slates do not look in 1587. A hundred years later, ten times that
like the American flag. In fact, the slates from Wales amount would be sent over. Other shipping records
can be generally categorized as dark purple, light show slates being exported from North Wales
green or black, although some of the purple is red- throughout the 1700s, and between 1729 and 1730,
dish and some bluish, and variations exist in all the over two and a half million slates were sent from
colors. In short, Welsh slate is quite similar to some Welsh ports, a million of these to Ireland.
of the slates of the American continent, especially The majority of the medieval roofing slates
Vermont slate, and it is practically identical to the that have been examined have square corners, with
slate of eastern Canada, at Burgoyne’s Cove in sides that are more or less parallel, and are quite
Newfoundland. small and thick. Their usual size is about seven
inches by three and a half to four inches. Today, such
HISTORY tiny slates are not available and even a six inch by
twelve inch slate is considered quite small. The early
One of the oldest slate quarries in Wales is Welsh slates remained small until the skill and the
the Cilgwyn Quarry in Nantlle, dating from the 12th expertise of the slate workers increased. In 1740 the
century. Other records mention a slate roof installed slates doubled in size, and later doubled again.
in 1317 on the huge Caernarvon Castle by “Henry le These slates were called “doubles” and “double-dou-
Sclatiere.” In 1399, a fellow named Creton, in refer- bles.” In the 1500s, Welsh shipping records showed
ence to a trip to a Welsh town just north of Bangor, slates ranging in size from 5” X 10” to 6” X 12” and
(Conway), wrote: ½ to ¾ inch thick. In contrast, most slate roofs
installed in America during the late 1800s and early
“So rode the King, without making noise, 1900s have uniform slates (all the slates on the roof
That at Conway, where there is much slate on the are the same size) ranging from 9” X 18” to 14” X
houses, He arrived with scarce a pause, 24”, and averaging 3/16” thick.
At break of day.” Slate had other uses in Wales besides roof-
ing. Many houses and buildings had walls built of
Records show a man named Sion Tudor slate stones still standing today in perfect condition.
ordering 3,000 slates in 1580 from Bangor, Wales, to A slate spindlewhorl used for the hand spinning of
replace the thatch roof on his house. In 1682, parts wool was found in Caernarvonshire in 1944 and is
of the St. Asaph Cathedral were slated with Penrhyn now displayed at the National Museum of Wales at
slates, and in 1930, nearly 250 years later, the same Llanberis. Slates were also used as bake stones,
slates were still good enough to be replaced on new probably from medieval times. They were similar to
wood on the same roof when the roof was redone, or our modern pizza pans, about an inch thick, and
so the story goes. A record of a lease in Wales during were used to bake bread known as “bara llech” or
the period 1568-74 reads: “slate bread.”
Ironically, the predominant type of roofing
“I did demise unto Gruffith one tenement called in Wales was not slate until the nineteenth century.

38 The Slate Roof Bible — Chapter 4 — Wales

s A sea of slate roofs best describes the town of Blaenau Ffestiniog, which rests stoically amidst the barren, misty mountains of North Wales.

t A tunnel in a Blaenau Ffestiniog slate mine. Some descend to 900 feet below the surface. Many have rail tracks for slate cars and trams.
The tunnels open into cavernous rooms where the slate was removed by hand, in candlelight, then winched to the surface and split into shin-
gles.

Photos by author.

The Slate Roof Bible — Chapter 4 — Wales 39

Prior to that time it was thatch, which is a thick and claimed, with considerable exaggeration, that
beautiful covering of reed that can absorb enough France’s blue slates soon turned “dirty grey,” while
water to become quite heavy, heavier even than slate. Germany’s red slates were “soft as clay,” and
It’s also flammable when dry, and it contributed to America’s slates were so rough as to be unsuitable
some of the great fires of the time, such as the Great for roofing houses. Admittedly, Welsh slate was
Fire of London. It doesn’t take too many Great Fires quite durable and lasted many years even in smoky,
before people start looking for a fireproof roofing acidic city environments, while some American
material such as slate. At one point in time it was slates “only lasted twenty years,” according to Welsh
declared in London that, “Every person who should slate workers, and some German slates were “even
build a house should take care that he did not cover it worse.” The best French slates were an exception,
with reeds, rushes, stubble or straw, but only with tiles, being much more durable.
shingles, board or lead.” Wooden shingles were also In 1901, a depression began that was in part
used for roofing, and around 1810, Thomas Pennant, attributed to the Boer War, leading to a scarcity of
while touring Wales, reported that in many regions money and increased unemployment. In 1906, the
“shingles, heart of oak split and cut into form of slates,” arrival of asbestos tile on the market further encour-
was “the ancient covering of the country.” aged the downward trend in slate production, which
The sale of roofing slate rises proportionally ultimately carried on into the first World War, never
as the construction of new buildings occurs, and fully to recover. An article in a 1910 Beautiful Homes
when new construction grinds to a halt, as during magazine described these new asbestos shingles as
war-time or economic depression, the production of being made of asbestos fiber and portland cement
slate is adversely affected. Slate production in Wales and coming in shades of either gray or bright red,
boomed in the 1800s, and the number of slate work- while costing no more than a slate roof. Incidentally,
ers nearly doubled from 1861 to 1881. But in the many asbestos roofs were also installed in the
1880s, a depression in the building trades in Great United States during the early 1900s, and many
Britain reduced the demand for roof slate. Although remain on American roofs today. People tend to mis-
the building industry stagnated in the 1880s, it take them for slate roofs, and some even insist on
picked up again in the 1890s, when new houses aver- calling them “asbestos slates.” However, asbestos
aged about 130,000 a year. However, by 1909, new roofs are not slate roofs and only vaguely resemble
houses had dropped to 90,000 a year, and by 1913 slate — although asbestos roofs will usually last at
they were down to 62,000. least 75 years.
While the slate industry was subject to the The number of Welsh slate mines dropped
vagaries of the building trends, it was also affected from 29 to 12 between 1914 and 1918. Building came
by foreign developments. Exports of Welsh slate almost to a standstill during the war, and in 1917, as
dropped off between 1889 and 1918 from nearly in the United States, slate quarrying was officially
80,000 tons to 1,500 tons. This was largely due to declared a “non-essential industry.” As a result,
World War I and the loss of Germany as a customer, skilled quarry workers were drafted into the mili-
as Germany accounted for 72% of Welsh slate tary, and many quarries closed for the duration of
exports in 1876, and many buildings in Germany the war.
were covered with such slate. The Germans were Although slate is still quarried in Wales
partial to the black slate of the Ffestiniog area, so today, in many areas, as in the United States, only
their loss as a customer hurt this area the most. abandoned quarries remain.
American slates began cutting into the
Welsh slate market by the end of the 1800s. In 1898, LIVING AND WORKING CONDITIONS
American slates were being sold in Dublin, Ireland,
at 25% less than Welsh slate, doing serious injury to Much of the slate mining in Wales was done
the Welsh slate market there. In 1897, Pennsylvania in three ways: the slate could be worked in terraces
was the leading slate exporter, followed, in order, by or shelves cut into the sides of a mountain as at
Vermont, Maine, Virginia, New York, Maryland, and Penrhyn or Dinorwic or large holes or pits could be
Georgia. Slates were also being imported into Great sunk into the ground as at Dorothea or the slate
Britain from France, Belgium, Norway, Portugal, could be brought out of the earth in tunnels or
Italy, the Netherlands and Germany. The Welsh mines.
slate industry fought back against the import of for- When the slate beds plunged deep under-
eign slates by pointing out their disadvantages. They ground, they had to be followed down via tunnels by

40 The Slate Roof Bible — Chapter 4 — Wales

the quarrymen in order for the slate to be extracted. NAME SIZE
The Llechwedd quarry near Blaenau Ffestiniog was Kings . . . . . . . . . . . . . . . . . . . . . . . . . . . .20” x 36”
one of the deep mines, and the interior of the mine Queens . . . . . . . . . . . . . . . . . . . . . . . . . .20” x 34”
was damp and totally dark. Its 25 miles of under- Princess . . . . . . . . . . . . . . . . . . . . . . . . .14” x 24”
ground tunnels connected 60’ chambers from which Duchess . . . . . . . . . . . . . . . . . . . . . . . . .12 “x 24”
the slate was removed. The workers adhered candles Marchioness . . . . . . . . . . . . . . . . . . . . . .11” x 22”
to the rock with clay in order to see what they were Countess . . . . . . . . . . . . . . . . . . . . . . . .10” x 20”
doing. The candles were expensive, and often only Viscountes . . . . . . . . . . . . . . . . . . . . . . .9” x 18”
one candle was shared by two people, especially if Lady . . . . . . . . . . . . . . . . . . . . . . . . . . . .8” x 16”
the second person was a young apprentice. Doubles . . . . . . . . . . . . . . . . . . . . . . . . .7” x 12”
The men drove holes into the rock face using Individual names were once assigned to each standard
six foot long iron bars called “Jwmpars” or size of roof slate. In 1933, however, the British Standards
“jumpers” in English. The bar was repeatedly Institution decided to dispense with such names and to
define sizes instead by length and width. Discrepancies
pounded against the rock to produce a hole, pro- existed when these names were used. Some sources list-
gressing six to twelve inches per hour. Blasting pow- ed ladies as 10x16, some as 12x14, small ladies as 8x14,
der was tamped into the holes, but not with an iron wide ladies as 12x16, and similar variations existed with
bar which could spark a disastrous explosion. A fuse the other names, which is probably why this nomenclature
was abandoned.
was then laid, which burned at a rate of an inch a Source: Brigden, “Turning Stone into Bread”; and Lindsay, Jean, (1974), A History of
minute, giving the men time to get out of the cavern the North Wales Slate Industry, p. 295; and Ffestiniog Slate Quarry, Blaenau
Ffestiniog, Wales

The author at the Blaenau Ffestiniog museum where the various sizes of roof slate made in
Wales over the years are displayed. Sizes range from 10”x 4” to 36”x 20”.
Photo by author.

The Slate Roof Bible — Chapter 4 — Wales 41

 s The Welsh Slate Museum at
Llanberis, built and roofed of slate,
was once the mill where slate from
the huge Dinorwic quarry was
processed. Note the mountain of
slate rubble in the background. The
museum now displays the old tools
and equipment, including the 50’
diameter water wheel which pow-
ered the mill’s 1/8 mile of line shaft.

Dafyyd Davies (right) a muse-

um worker, demonstrates the rhyth-
mical motion needed to trim slates
with a “stool and traverse.” The
“slate knife” he holds can still be
bought in hardware stores in Wales
today.

Photos by author.

42 The Slate Roof Bible — Chapter 4 — Wales

and find shelter in the tunnel during the explosion. Edward Davies fell 20 yards while trying to unhook
Large blocks, two to three feet thick and up chains from a wagon, and died. This was about the
to ten feet long, were brought down by the blast and same time another man was killed at the quarry by a
were broken up by the rockmen with a hammer and runaway truck. Later, John Watkin was killed when
chisel, then loaded onto trolleys by a chain hoist and the earth above him collapsed as he excavated a
tripod, and winched to the surface. “Badrockmen” reservoir, and a few months later, Tom Rogers got his
were paid by the ton to remove non-productive rock, coat caught in a rotating turbine shaft and was
and “rubblers” cleared the waste. killed. John Lewis was later trapped by a falling rock
At Llechwedd, the men worked each cham- and killed; David Roberts was hit and killed by a
ber in teams of four, two in the chamber and two on falling stone weighing 30 pounds; Richard Davies
the surface in the mill. The two rockmen below the was struck and killed by a rock falling from a cham-
surface extracted the slate and sent it up to their ber roof; David Evans was killed by a rock weighing
partners above, who broke the slabs down further, 25 tons; Owen Ellis fell about 50 feet and was killed
finally splitting and trimming out the roof slate when climbing down a chain being used to lower a
using only hand tools. Other quarries used four, six block of slate; Tom Ellis was killed a few months
or eight men to a team. later when hundreds of tons of rock from a chamber
In 1876, a quarry worker wrote, “When I was roof fell on him; David Owen fell down a shaft he
a child, I had to walk five miles before six in the morn- was exploring out of curiosity, and died; David
ing, and the same distance home after six in the evening; Davies fell backwards over a ledge when his crowbar
to work from six to six; to dine on cold coffee, or a cup of slipped as he was working a stone; Edward Lewis
buttermilk and a slice of bread and butter. Some of the died when the ledge he stood upon gave way, crush-
men had to support a family of perhaps five, eight or ten ing him; and numerous others died from similar
children on wages averaging 60 pence to 80 pence a causes.
week.” In the deep mines, slate had to be left in
Apprentices received no pay for the first six place as supporting walls in order to prevent under-
months, and had to wait nine years before they mining and consequent disaster. However, some
received full pay. Some quarries had their own wood profit-hungry quarry operators robbed these support
shops, pattern shops and foundries, where they walls, thereby thinning them or removing them alto-
made their own tools and parts for their equipment. gether. In 1883, no less than six and a quarter mil-
Men living too far from the quarry to travel lions tons of overburden and slate collapsed on the
home stayed in barracks and only traveled home on workings of the Welsh Slate Company due to irre-
weekends. The men worked outside during all types sponsible undermining. The owner of the land,
of weather, and some quarries provided eating hous- William Edward Oakely, sued the mining company
es and places with a fire where the men could dry for compensation for the damage done to his assets,
their clothes. Typical meals consisted of tea, egg, and and won his claim in one of the longest arbitration
bread and butter for breakfast; tea and bread and disputes in legal history.
butter for lunch; bread and butter for teatime; and Men of North Wales who didn’t work in the
potatoes, sometimes with beef, bacon or buttermilk quarries lived to an average age of 67 years, while
for supper. quarry workers were likely to die by the age of 38.
Quarry work was hard and dangerous; over Many of the quarrymen suffered from respiratory
four hundred men and boys have been killed in the diseases because of the dust in the quarries.
Penrhyn Quarry since 1782, and one quarryman, Ironically, quarry medical personnel disagreed. At
Robert Williams, in 1792, had as his gravestone the the Penrhyn Quarry Hospital in Bethesda, medical
piece of rock that fell on him. Fatal accidents at the officer J. Bradley Hughes issued a written statement
Bryneglwys Quarry also occurred year-round, and on June 1, 1922, stating, “We have no case of silicosis in
varied in cause, although records reveal typical caus- this quarry of which I am aware, and I became con-
es of death: a worker named Owen fell 18 yards down vinced after four years’ experience here that slate dust is
a shaft and died. A few years later, William Owen not merely harmless, but beneficial.” Dr. E. Shelton
was knocked over a ledge by a falling rock while bor- Roberts, who had a very long acquaintance with the
ing a hole. He injured his spine and died the next conditions both at Penrhyn quarry and at other
day. A few months later, a piece of rock weighing 7 quarries in the district, further maintained that he
tons fell on David Evans and Hugh Jones and had not met a single case of silicosis or lung trouble
crushed both of them to death. Ten days later, among the quarrymen attributable to their work at

The Slate Roof Bible — Chapter 4 — Wales 43

 A “drumhouse” (right)
housed a large drum
(below), with heavy
cables wound against
each other. Slate cars
attached to the cables
were let down from the
mountain top on iron
rails. The weight of the
cars loaded with slate
pulled the empty cars
back up the mountain. A
brake lever controlled
the operation. These
long abandoned relics
remain intact at the
Dinorwic Quarry, adja-
cent to the Welsh Slate
Museum.

Photos by author.

44 The Slate Roof Bible — Chapter 4 — Wales

 (Bottom left) Looking up the first incline from the bottom of
the mountain at Dinorwic. Old rails are clearly visible. The
lowest drumhouse, pictured on the previous page, sits at
the top of the photo.

(Top left) Looking down toward the lowest drumhouse,

which now sits around the corner to the right.

(Top right) Looking up another incline toward the top of the

mountain. Abandoned slate mill sits at right. This quarry
(Dinorwic), covering 700 acres, had 50 miles of iron track.

Photos by author.

ANALYSIS OF TYPICAL SLATE OF NORTH WALES (%)

Silica . . . . . . . . . . .55.30
Oxide of Iron . . . . .10.00
Alumina . . . . . . . . .24.84
Lime . . . . . . . . . . . .0.36
Magnesia . . . . . . . .2.46
Carbonic Acid . . . . .nd
Sulphuric Acid . . . .0.21
Potash . . . . . . . . . .1.47
Soda . . . . . . . . . . .0.53
Water of Hydration .4.70

[Source: Lindsay, Jean, (1974), A History

of the North Wales Slate Industry, p.
292]

The Slate Roof Bible — Chapter 4 — Wales 45

 The card of prices (left) is an
authentic document from the
North Wales slate industry, as
are the documents on the fol-
lowing pages related to the
attempts to unionize the quar-
ries in the 1800s.

Three jobs involved in producing roof slates: the fellow on the right is splitting blocks into smaller pieces, while the man in the center splits
them down further into roof shingles. The man on the left is trimming the slate with a slate knife and a “stool and traverse.” The Welsh don’t
punch (“hole”) their slates at the quarry as Americans do. They let the roofers do it on the job site. (Courtesy of Old Line Museum, Delta, PA)

46 The Slate Roof Bible — Chapter 4 — Wales

the slate quarries. Dr. John Roberts, general practi- to a worker of sim-
tioner with 39 years experience in a quarry district ilar religious or
wrote, “During my experience it is remarkable to say political bent,
that no quarryman has ever complained of cough or while poor rock
choking sensation due to inhalation of slate dust. . . I faces went to oth-
have not examined slate dust microscopically, but am of ers. This forced
the opinion that the particles are soft and none irritant, the men to form
also it contains very little silicate and a good deal of iron unions and to take
and sulphur, the latter is regarded as a germicide. . . The their complaints
facts already stated and my experience convinces me, that to the manage-
slate dust is neither an irritant exciting or a predisposing ment by union
cause of Tuberculosis. There is no doubt that the quarry- committee in
man’s mode of living and poor feeding consisting mainly order to protect
of tea, bread and butter reduces their resisting power the individuals
against Tuberculosis.” with grievances
Of course, the doctors who issued these from losing their
statements were on the payroll of the slate quarries, jobs.
and their reports were used by the North Wales The first
THREE TYPES OF QUARRY
Quarry Proprietor’s Association to downplay any union attempt
OPERATIONS, SIMPLIFIED
detrimental effect on the health of quarry workers occurred at
caused by the quarry environment. The North Wales Penrhyn Quarry in Top: Pit Quarry (Dorothea and
Quarrymen’s Union responded to the above state- 1865, where 1,800 Penrhyn).
ments by issuing a statement of their own, declaring, men joined, and Middle: Open quarry showing
galleries or shelves
“That we cannot agree with the statement of the case as soon lost their
(Dinorwic).
submitted by the North Wales Quarry Proprietor’s employment as a Bottom: Deep mine showing hori-
Association. It is perfectly obvious to us that no reliance result, until the zontal shafts entering into
can be placed on the statements submitted by them . . . In union was broken. the side of a mountain
our view there is not sufficient data available to form a The union organ- (Blaenau Ffestiniog).
Shaded areas show slate
definite opinion one way or the other as to the effect of izers were subse- deposits.
slate dust on the internal organs, although our members quently fired. This Source: Williams, M. (1991)
are convinced that it is chiefly responsible for bringing on attempt at union-
some forms of Phthisis [Tuberculosis].” izing caused quar-
By the 1950s, however, according to J. G. ry owner Lord Penrhyn to issue a statement on
Isherwood in Slate From Blaenau Ffestiniog (1988), December 2, 1865, advising the men “to consider well
“the quarries had been decimated. . . All were pale before listening to agitators,” and offering “a word of
shadows of their former selves, their workforces rav- caution to avoid having anything to do with such a
aged by the effects of silicosis, a disease ignored for movement as a trade union in future, as on the very first
too long by many quarry owners until the evidence rumor of such a state of feeling, he will immediately close
was beyond doubt; the most experienced men had the quarry, and only reopen it and his cottages to those
received the greatest exposure to the killing dust men who declare themselves averse to any such scheme as
and so the dearth of experienced miners and rock- a trade union.” The closing of the quarry and the
men increased.” men’s cottages would subject the men to extreme
The struggle between the Welsh quarry hardship, especially in the winter months, while
workers and the quarry owners was bitter at times. Lord Penrhyn could simply wait it out in the
The men who dared to complain about the working Penrhyn Castle, relying on his wealth and servants
conditions could simply be fired from their jobs and to continue an opulent lifestyle. A saying eventually
possibly evicted from their homes, as quarry owners arose, attributable to Lord Penrhyn’s acquisition of
were often both employers and landlords. land holdings, “Steal a sheep, they hang you, steal a
Despite the tough working conditions, a mountain, they make you a lord.”
principal complaint among the workers concerned In 1870, over 80 Penrhyn quarrymen, among
the corruption, bribery, favoritism and discrimina- the best in the quarry in character and skill, were
tion which seemed to prevail among the quarry offi- fired without reason, although it was widely believed
cials, who would grant a good rock face (a “bargain”) that the men were fired for political reasons. A letter

The Slate Roof Bible — Chapter 4 — Wales 47

 s Abandoned buildings at the Dinorwic Quarry. Note entire mountainside removed in background.

Opposite: Slate walls, some with slate shelters built into them, line most pathways.

t Workers barracks at Dinorwic, long abandoned — no trace of the roofs remain.

Photos by author.

48 The Slate Roof Bible — Chapter 4 — Wales

written by an apparent mediator in 1874, during matter we maintain that clear and offensive favoritism is
another strike, perhaps sums up the situation suc- shewn. . . Let honest work be paid for and not the
cinctly: “Over 2,200 quarrymen are out on strike and Political or Religious creed of any man . . .” Shortly
about 300 old men have been ‘turned out’ by Lord thereafter, it was agreed that no worker would be
Penrhyn for whom some provision must be made to keep discriminated against because of religion or politics,
them from the Union House. Some of these old men have after which Dinorwic experienced a considerable
been working at Lord Penrhyn’s quarries for 40, 50 and period of peace.
60 years, and some of them even more than this; and sim- Penrhyn Quarry was not so lucky. Lord
ply because the bulk of the quarrymen resolved to ask for Penrhyn refused to recognize the right of union
an increase of wages, these poor, innocent old men were committees to take up grievances on behalf of the
being cruelly punished by being thrown upon the Parish workers. A lengthy strike followed in 1896, but work
for any provision Lord Penrhyn was ready to make for eventually resumed without any grievances being
them. This certainly is not charity!” settled. Worker discontent culminated in a three-
A more successful, broader union formed in year strike at Penrhyn from 1900-1903, having a dis-
1874 at the Dinorwic Quarry, attempting to unionize astrous effect on the local town, Bethesda. The mili-
all the slate quarries in North Wales, and was met by tary was called in to keep order as thousands of
the uniform hostility of the quarry owners. The quarry workers and their families were threatened
owner of the Dinorwic Quarry attempted to exclude with starvation. The specter of “Socialist experi-
all unionists from the quarry, leading to a five week ments” was raised in the Tory press, depicting the
walk-out until the union was recognized. Another work of the unions to be a creeping menace. Lord
strike occurred at Dinorwic in 1885-6, as a result of Penrhyn adamantly refused to give in to the demand
complaints by the workers of favoritism. “We respect- that he recognize union grievance committees, and
fully invite you to examine the grounds for the following the strike eventually failed. The union carried on,
complaints; and if you approve of it we shall be ready to however, and Lord Penrhyn eventually became “The
appear before you to discuss this, and to enter into partic- most hated man in the world,” according to a worker at
ulars if required. We complain that at present, and for the Welsh Slate Museum, who added, “We Welsh don’t
some time past, we are not treated as workmen, but that like to talk about him.” And that was the sentiment
the question of our politics and religion are allowed to still in 1996, nearly a century later!
affect the question of our work and our wage. In this The British government did pass the Quarry

The Slate Roof Bible — Chapter 4 — Wales 49

50 The Slate Roof Bible — Chapter 4 — Wales
Fencing Act in 1887, followed by the Quarries with your own land.” On January 2, 1871, another
Regulation Act in 1889, and the 1894 Quarries Act, wrote, “My old friends in Lleyn [North Wales] can have
initiating government inspection of quarries and a small holding for themselves [in America] for the money
quarry machinery. In addition, the Workman’s they pay in rent for one year in Wales. One need not fear
Compensation Acts of 1880 and 1911 provided any notice to leave from any landlord or steward for vot-
greater protection for the workers. ing according to conscience. I never met anyone yet who
Otherwise, workers turned to their church regretted coming to this country, but only many who were
and/or pub for consolation during hard times. In sorry they had not come before.”
one small mining village there were more than 29 And so, the Welsh immigrated to America,
places of worship within three miles of the center. discovering slate in York County, Pennsylvania, in
The chapels were the centers of the community, and the 1700s, and establishing the town of Bangor,
were used for important meetings as well as for song which became Bangor West, and is today known as
and worship. On the other hand, pubs provided Delta, PA, where a large Welsh church graces the
some competition as meeting places, and in some main street. In the Lehigh-Northampton district of
towns the pubs matched the places of worship, pub Pennsylvania, the Welsh discovered slate in the
for chapel. By 1880, there were 35 pubs in the tiny 1800s, and once again a town named Bangor sprung
town of Bethesda alone (near the Penrhyn quarry). up where it still exists today, just a few miles from
It’s no wonder that the lure of America another town — East Bangor. Both Bangor and
became so strong to many of the Welsh people. In Delta, PA, remain as strong centers of Welsh influ-
America, they could own their own land and their ence in the US. Another Welsh settlement grew at
own home with a garden and livestock, and without Wind Gap, PA, in Northampton County, not far
the meddling of landlords. Letters of Welsh immi- from Bangor.
grants spoke of the opportunity they found in Vermont fared much the same way. The bor-
America. On January 29, 1869, one wrote, “I am der between Rutland County, VT, and Washington
amazed by the efforts made by the Welsh in Wales to get a County, NY, became a Mecca in the 1850s for Welsh
farm. When one comes vacant, there are hundreds trying immigrants drawn to the slate quarries. Many small
to get it. But here you can be your own master without Welsh settlements sprang up, including Fair Haven,
fear of being turned out and you can do what you like Blissville, Poultney, South Poultney, Pawlet and

t A sign that speaks for itself.

Photo by author.

The Slate Roof Bible — Chapter 4 — Wales 51

 West Pawlet, all in Pennsylvania, Ohio, and New York attracted
Vermont, and in over one third of the Welsh immigrants and their
Granville and West children, while Illinois, Wisconsin, Iowa, Utah,
Granville, New York. Kansas, Colorado, Indiana and California attracted
One strictly Welsh lesser quantities, in that order. Welsh were most
organization from numerous in Pennsylvania in the coal mining and
the region, the steel areas such as Pittsburgh, as well as in the slate
Poultney Welsh areas already mentioned. The census of 1900 shows
Male Chorus, was still the Welsh most concentrated in Pennsylvania in the
being organized as late Wilkes Barre-Scranton area, Pittsburgh and other
as 1939. coal mining areas as well as slate regions.
Other Welsh immigrants The Welsh quarry workers who stayed in
were drawn to the Virginia slate regions, concentrat- Wales continued to put in a good day’s work,
ing in Arvonia, a town named after Caernarvon, although the quarry managers could never squeeze
Wales. Others were drawn to the Rockmart and enough out of them. In 1913, for example, each
Fairmount areas of Georgia. Welsh emigration to Welsh mine worker averaged 33 tons of finished
America reached its peak by 1900, with nearly slate per year, and each quarry worker averaged 32
94,000 total immigrants and over 170,000 children of tons. Despite the workers’ long days, the manager of
Welsh immigrants present by that time. The signifi- the Penrhyn Quarry insisted that they only worked
cance of this emigration is drawn into perspective seven and a half hours a day “after deducting the meal
when we realize that the entire population of hour. And then there is the time when the men are not
Caernarvonshire in 1871 was only 106,000, and in working, such as blasting time, and if you add to this the
Merioneth only 46,000, while the population of loss of time such as holidays, attending funerals, hay har-
Wales in its entirety in 1871 was only 1.2 million. vest, and rough weather, the actual working time becomes
This means that nearly 7% of the entire population small.” Note that he even complained about the men
of Wales had emigrated to America by 1870, or in attending funerals! With management like that, it’s
today’s terms, that would be like 18 million easy to see why the workers wanted to leave the
Americans emigrating to (for example) China. country.

52 The Slate Roof Bible — Chapter 4 — Wales

 s An old section of the Penrhyn Quarry as it looks today.
The pit has filled in with water, but the terraces cut into the mountainside are clearly visible.
t Meredith Tanyard Cottage in Dollgellau, Wales, an old cottage with a restored roof.
Photos by author.

The Slate Roof Bible — Chapter 4 — Wales 53

 s The author on a self-guided tour of a hotel in Wales.
Opposite: Welsh slate walls and roof of the Llanberis area near the Dinorwic Quarry.
Welsh slate is very similar to Vermont and Canadian slate in color and durability.
Top photo by Jeanine Jenkins, opposite by author.

54 The Slate Roof Bible — Chapter 4 — Wales

The Slate Roof Bible — Chapter 4 — Wales 55
 Chapter Five

VERMONT – NEW YORK

T
he “Slate Valley” of Vermont lies place in 1839 near Fair Haven, Vermont. A fellow by
mainly in Rutland County, but also the name of Colonel Alonson Allen started the quar-
straddles the state border to include ry at a place called Scotch Hill, just north of Fair
some of Washington County, New York. The 24- Haven. Allen was born in Bristol, Vermont, on
mile-long, six-mile-wide valley extends from August 22, 1800, settling in Fair Haven at the age of
Granville, NY, and West Pawlet, VT, north to Fair 36 as a proprietor of a small general store. He start-
Haven, VT. The roof ed his slate quarry with Caleb B. Ranney.
slates from this area For a few years, Colonel Allen dabbled
are well known both experimentally with slate; then in 1845, he went into
for their durability the business of making school slates. In the mid-
and for their variety 1800s, hand-held pieces of slate were used by school
of colors, ranging children instead of paper writing tablets, and much
from deep red to solid of the slate quarried at that time was used to pro-
purple, purple with duce these school slates. In fact, slate was also used
green flecks or to make slate pencils, which were made entirely of
streaks, gray-green, solid slate (no wood or graphite). A slate pencil was
solid green, “sea about three or four inches long and a quarter inch in
green,” gray with diameter, pointed at one end and used for marking
black streaks, gray- school slates, much the same as a pencil is used to
black and black. mark a piece of paper today. When a sharp piece of
This differs greatly slate is dragged across a flat piece of slate, a white
from the slates of Monson, Maine, eastern mark remains on the flat piece, which is easily
Pennsylvania, Peach Bottom, PA, or Buckingham, rubbed off by a piece of cloth or even a child’s hand.
VA, which are all a shade of black or gray. Although Chalk is not needed when one has a slate pencil.
some green, purple and blue slate may be found in And so, thanks to the quarrying of slate, many
eastern Canada, at Burgoyne’s Cove in schools were provided with both “tablets” and writ-
Newfoundland, as well as in small deposits in ing utensils for the children. In addition, slate
Arkansas, Tennessee, Georgia and Utah, the only “blackboards” hung on walls and were used by
commercial source of colored slate in the United teachers and students. Today we have sayings such
States, of any significance, lies in this area strad-
Photo by author.
dling the border between New York and Vermont.
The bulk of the green and the purple slate is
found on the Vermont side of the valley, and all of
the red slate is found on the New York side. It can be
fairly said that all of the true red slate in America,
and perhaps the world, comes from Washington
County, NY. First discovered in the 1850s near
Green Pond in Hebron, in an area now known as
Slateville, red slate is now one of the most durable
(and most expensive) slates available anywhere.
The slate quarried from the Vermont side of
the valley is primarily green, “sea green” (green that
develops a mottled reddish cast over the years) and
purple, but also includes some Vermont black and
gray.
The first quarrying in the Slate Valley took
The Slate Roof Bible — Chapter 5 — Vermont/New York 57
 as “wipe your slate clean,” or have a “clean slate,” or
events are “slated,” or a “slate” of candidates. These
are all carry-overs from the days when slates were
used as writing tablets.
Colonel Allen didn’t stay in the school slate
business for long, however, because he found he
could make more money making roofing slates,
which were about the same size and thickness as
school slates. He began roofing slate production in
1847-48, just two years after starting the manufac-
ture of school slate; then he abandoned his school
slate production in 1848.
The first slate roof covered by Vermont slate
was done by Colonel Allen in 1848, but the farmer
who owned the roof was a skeptic. He insisted that
Colonel Allen wait a full year for payment in order
to determine if the roof would collapse under the
weight of the slate. If the roof did collapse, Colonel
Allen was to receive no pay, and he was instead to
pay for all damages. It turns out that the roof passed
the test and lasted quite a bit longer than the skep-
tic’s one-year trial period. In fact, it reportedly still
exists in good condition today, over one hundred and
fifty years later.
Allen also served as state senator in 1842-3,
and as an assistant judge of the county court in the
early 1860s. In 1886, eight years after Allen’s death,
a Rutland County historical account stated, “but for
his boldness and courage, to this hour not one slate would
have been shaped from Fair Haven to Salem.”
MAP SHOWING SLATE REGION Colonel Allen opened a floodgate in 1848,
OF VERMONT/NY after which slate quarries, following his example,
began popping up everywhere. The “Eagle Quarry”
Indicating Rutland County, and towns of Fair Haven,
Poultney, Wells, and Granville (NY) was opened just outside of Poultney, Vermont, in
1848; then in 1851, another quarry opened on a farm
[Source: Report of the State Geologist on the Mineral Industries and Geology owned by Daniel Hooker, three miles north of
of Vermont 1913-14, George H. Perkins, Free Press Printing Company, 1914]
Poultney village. Hooker and Son quarried a few
slates in 1851, then a few more in 1852, as they were
able to sell them to their neighbors. By 1854, they
had a full-fledged operation going, manufacturing
mainly roofing slate and eventually employing as
many as 60 men. Some of their slates were of such
high quality they were even exported to England.
Then Welshmen began opening quarries right and
left. By 1885, forty-six years after Allen started the
first quarry in Vermont, 67 slate quarries were oper-
ating in Rutland County.
By 1871, slates were also being manufac-
tured for mantels, billiards tables, hearths, table
tops, blackboards, floor tiles, door steps and other
articles. Some slate was “marbleized,” which
involved a process of painting the slate black, heat-
ing it to 1750 F, then dipping it in water that had
58 The Slate Roof Bible — Chapter 5 — Vermont/New York
paint floating on the surface. The slate was baked they called it. He became quite an expert at slate,
again, varnished, baked again, polished and baked a and helped many a person who wanted to start a
fourth time until the final product looked incredibly slate quarry. “He could look at the rock on the top and
similar to marble. An 1875 description of the process tell them how to start whatever they did to the slate.
states, “The ingenious process of marbleizing is one of the They have to get it in a certain vein or something and he
recent inventions. By a certain chemical process the sur- could do that,” she said. He worked in the pit in
face of the slate, after it receives a polish, is converted into Vermont until about a year before he died.
the exact semblance of the most beautiful of the foreign Once in Vermont, Eleanor found that her
and domestic marbles, and also made to imitate rose- church was Welsh and all the services were in Welsh.
wood, mahogany and ash, and so exactly that the most She went to church seven days a week, as it was the
experienced would be puzzled to detect the difference center of her social life. “The Welsh sang all the time,”
from sight.” according to Eleanor, whose dad, uncle and brother
One typical quarry by this time was being sang in choirs and choruses.
worked to a depth of 150 feet from the surface, all The slate they quarried was for roofing mate-
dug without today’s modern machinery. From this rial. “This whole area is slate. There are many, many,
pit opening, six tunnels were dug into the hillside to many colors, beautiful colors. Middle Granville [NY] has
a distance of 600 feet, the slate being removed on a beautiful red. And then there’s purple and black, gray.
railways operated by steam. The slate deposits in Then there’s one that’s sort of mottled green and purple.
this area were considered “inexhaustible,” and still It’s awfully pretty.”
exist in huge quantities today. Life in the quarries could be very hard,
By 1872, over 11,000 tons of roofing slate according to Eleanor. “I’m very happy I don’t have
were being shipped annually from Poultney, anyone in the slate quarries anymore. We were brought
Vermont, amounting to about 35,000 squares of roof- up to get your bed made, your dishes done and your floor
ing — enough to cover roughly 3,000 average hous- swept, in case somebody gets hurt and they bring them
es. The cost per square was then about $4.50. The home from the quarry. That was the way you were
cost today (2003) is about $350.00. brought up. My father was hurt badly. He was uncon-
Visitors to the Slate Valley today can camp at scious for 21 days. They operated on his brain. He was
Vermont’s beautiful Half Moon Pond State Park,
and see the old Scotch Hill quarries along Scotch Since there are so many century-old sea green slate roofs in the
Hill Road, which connects the park to the lovely United States, it’s important to know that 100-year-old sea green
slates are usually still very durable, and may yet last another 100
town of Fair Haven. While in the area be sure to visit years. Although most sea green slate is classified as hard, some
the Slate Valley Museum, 17 Water Street, Granville, sea green quarries produced a softer slate which may appear
New York 12382 (Ph: 518-642-1417); or visit the web brownish and flaking with age. These may be relatively soft and
may only last 150 years, or less.
site at http://www.slatevalleymuseum.org.
Eleanor Evans McMorrow was born in Wales ANALYSIS OF VERMONT/NY SLATE (%)
near Caernarvon, and came to Vermont with her par-
ents in 1924, at the age of seven. She reminds us that Sea Unfading Purple Red
“Caernarvon” Street in Fair Haven is an example of Green Green

the Welsh influence in the development of this area Silica . . . . . . . . . . . . 65.02 . . . . 64.71 . . . . . 62.37 . . . . 73.93
of the United States. Almost all of the Welsh in the Protoxide of iron . . . 5.44 . . . . . 5.44 . . . . . . 4.21 . . . . . 1.74
Peroxide of iron . . . 2.99 . . . . . 7.23 . . . . . . 7.66 . . . . . 10.17
Vermont/New York slate region were from North Alumina . . . . . . . . . 16.02 . . . . 7.84 . . . . . . 13.40 . . . . 5.16
Wales where the Welsh slate quarries are located, Manganese Oxide . 0.31 . . . . . 0.30 . . . . . . 0.20 . . . . . 0.10
she says, while those Welshmen from South Wales, CA Carbonate . . . . . 1.38 . . . . . 3.00 . . . . . . 2.50 . . . . . 1.25
CA Sulphate . . . . . . 1.31 . . . . . 1.55 . . . . . . 0.16 . . . . . 1.06
who mostly worked coal, immigrated to Phosphoric acid . . . trace . . . . trace . . . . . trace . . . . . trace
Pennsylvania to work the coal mines. Alkalies (NA) . . . . . 4.16 . . . . . 6.92 . . . . . . 7.20 . . . . . 3.92
Eleanor’s Welsh maternal grandparents had Water . . . . . . . . . . . 1.37 . . . . . 1.38 . . . . . . 1.50 . . . . . 1.24
Magnesia . . . . . . . . 2.00 . . . . . 1.63 . . . . . . 0.90 . . . . . 1.43
lived in Vermont in the mid-1800s but they eventu- Carbon: . . . . . . . . . . None
ally returned to Wales. Her maternal uncles had also Ferrous Oxide: . . . . 4.71%
Strength: . . . . . . . . . 11.040 lbs/sq. in. (modulus of rupture)
moved from Wales to Poultney, and in doing so Porosity: . . . . . . . . . .220% water absorbed in 24 hours
influenced Eleanor’s parents to make the great Corrodibility: . . . . . . .722% of wt lost in acid sol. for 63 hrs
Atlantic journey themselves. Her father started
(Source: History of Rutland County, Vermont, edited by H. P. Smith and W. S. Rann, D.
working in slate in Wales when he was eleven, not an Mason and Co., Syracuse, NY, 1886, p. 198. Data attributed to Professor J. Francis
Williams, Rensselaer Polytechnic Institute, Troy, NY.;
uncommon age for Welsh lads to start in the “pit,” as and U. S. Geological Survey, date unknown)

The Slate Roof Bible — Chapter 5 — Vermont/New York 59

 s Mountains of waste slate like the one above near Poultney,
Vermont are a common sight in quarry regions.
Photo by Jeanine Jenkins.

Slate splitter — Hilltop

Slate Co., Middle
Granville, New York

All photos by author

unless otherwise specified.

Much of the history of the Vermont/New York slate valley can be stud-
ied at the Slate Valley Museum, 17 Water Street, Granville, New York
12832 (phone: 518-642-1417). The engraved slate plaque, above, is
on display at the museum.

s Modern block cutter at U.S. Quarried Slate Co., Fair Haven, VT,
splitting an incoming block using a hammer and a chisel.

s James Kelly of Wells, VT, is one of the few remaining black-

smiths still making tools for the slate industry.

60 The Slate Roof Bible — Chapter 5 — Vermont/New York

home for nine years after it. He had to learn to write and York near Granville, is a deep, solid (not mottled)
everything over again, learn to talk.” red similar in color to red brick, and does not resem-
“They have these big blocks they send up. It was ble sea green slate at all.
a bad day, it was sleeting. A block came out of the chain Thanks to Margot McKinney, a reference
and hit him in the head. My father got $9.00 a week in librarian at the Green Mountain College in Vermont
compensation. I don’t know how they made ends meet, if in 1976, a direct history of the sea green quarries has
they did.” been put on record. We are even more grateful to
There were always injuries, says Eleanor, Owen L. Williams, the author of the history, who, at
who tells of broken arms and broken legs. “Somebody the age of 89, in 1969, penned his fifth revision of
was always getting killed, it was terrible. More so here “The History of the Sea Green Quarries,” on a six inch
than in Wales, I think, from what I’ve heard them tell. by nine inch dime store tablet. Margot McKinney
Over there the quarries were mined in shelves. And here, found and typed the contents of the tablet after Mr.
right down.” Williams died in 1975 in Wells, Vermont, and
The huge dumps of waste slate around the recorded it in the school records of 1976, where it
quarries were also hazardous, according to Eleanor. found its final resting place in a manila envelope in
“The man that was boarding with us, ten days after my a drawer in an upstairs room in the school library.
father was hurt, this guy made him go and work in the Here it is now excerpted and paraphrased to provide
same spot my father was in. These dumps get icy, they a first-hand account of the sea green quarries “by an
slide. And it slid and killed him. He was knocked right off old slate maker of over sixty years experience. . .”
the ledge and into the quarry. He was killed ten days Owen Williams was born in 1880 in
after my father was hurt. Today they wouldn’t be able to Caernarvonshire, Wales, and emigrated to the
allow that because of your safety codes. But they didn’t United States in 1901. Twenty-six years later he sat
have safety codes back then, in 1938.” in the Vermont Legislature, despite the fact that he
never had any formal education beyond the seventh
SEA GREEN SLATE grade.
He wrote “The History of the Sea Green
Vermont is a beautiful state, and it has pro- Quarries” five times, each time a revision of the pre-
duced perhaps more hard slate than any other. “Sea vious version, all handwritten on 6 x 9-inch tablets.
green” (now known as semi-weathering gray or gray- The final version, written in 1969, bore the words,
green) slate roofs can be found at almost any loca- “This is the last I wrote.”
tion in New England served by railroads at the time The sea green quarries were located in the
the slate was quarried, although many areas not southwest part of Rutland County, Vermont, specifi-
served by railroads at that time do not have slate cally near Fair Haven, Pawlet, Poultney and Wells.
roofs today, and never did. For example, just a few The slate deposit covered about 10 miles or more,
miles east of the slate quarrying region of Vermont, and varied in width from a few hundred feet to half
over the Green Mountains, slate roofs are hard to a mile or so.
find, as there was no railroad access to that area dur- According to Mr. Williams, various records
ing the heyday of slate quarrying. On the other show the opening of the first sea green quarry to
hand, Vermont’s sea green slate can be found hun- have taken place in the late 1860s or early 1870s.
dreds of miles away to the south and west where the The sea green slate deposits were, of course, below
rail lines routinely hauled the slate to Pittsburgh, the surface of the earth, and an excavation had to be
and farther west into Ohio and beyond. sunk into the ground in order to access the slate and
Sea green slate is easily identifiable because begin to open a quarry. It was necessary for the quar-
the roof will appear light gray with reddish slates rymen to put one or several holes down and blast out
scattered throughout — it only appears “sea green” a section of overlaying rock, in order to reach the
when freshly quarried. The reddish color is also slate and determine whether the slate was of ade-
called buff, tan, pink, orange, rust or brown, but quate quality to continue. If the slate looked prom-
since it is caused by the oxidation of iron layered ising, then more holes were drilled at an angle corre-
into the slate itself, we may as well call it reddish. sponding to the layers of the slate, and blasting was
People in the slate industry do not like to use the continued until the quarrymen had cut a “butt and a
term “red” when describing the mottled color of sea fireside.” “These terms,” states Mr. Williams, “are used
green slate because true “red” slate, quarried in New by quarrymen. Please bear in mind that these terms that

The Slate Roof Bible — Chapter 5 — Vermont/New York 61

I use in this history prevailed in the early days with noth- a hammer. The tapered wedge caused the block of
ing but hand labor.” slate to split in two, while the feathers provide a
When the overlying rock was covered by soil, smooth surface allowing the wedge to be driven into
sand or clay, a team of horses with a scoop shovel the hole. This way, slate can be split along a plane
would drag a trench across the vein to expose the perpendicular to the layering of the stone.
rock. Then, using the same technique, the trench Instead of a drill, a “jumper” could be used to
was widened until the rock could be reached and plug a piece of slate. A jumper is a steel rod about six
blasted. The overlying rocky slate was often not solid feet long with a small, but heavy ball of iron welded
enough “as quarrymen say to make roofing slate of good into it about fifteen inches from the end to provide
quality and durability” to a depth of ten to fifteen feet, additional weight in the drilling process. This tool
although in some years the top rock was in demand required a good deal of experience in order to drill a
to make antique-looking (“freak”) slate. hole suitable for a plug.
In those early days of slate quarrying, all Another tool frequently used by quarrymen
labor was done by hand. Hand shovels were used to was the gouge. According to Mr. Williams, the gouge
take care of the rubbish, and elm or oak plank boxes, was made of 5/8-inch steel, about 10 inches long
braced with strap iron and measuring four feet wide (when new) with a point suitable to cut across the
and five feet long, were used for moving slate, and endgrain of a stone, in order to sculp it — make a cut
for dumping scrap. At the turn of the century (1900), the length of the stone perpendicular to the obvious
self-dumping boxes came into use, made of iron. cleavage plane. If the resulting ditch on the end of
Other tools included both double and single-hand the stone was cut smooth and straight, the chiseled
hammers (requiring one or two hands), crow bars, split would be very good and made in the direction
drills, wedges, chisels, gouges, rope, black powder desired, but if the ditch was not made right and
and fuse. Dynamite was used on poor rock, but straight, the result would be very unsatisfactory, and
never on good slate rock “on account of the shattering if so would require more labor and a waste of valu-
effect.” able stock.
Drilling was all done by hand. One man held Once the stone had been split to a size that
a metal rod fitted with a drill bit on its end, while was workable, it had to be hoisted out of the pit. This
another man (or two) struck the rod with a double- was done using a crow bar to manipulate the block
handed hammer. The man holding the rod turned it while a chain was securely wrapped around it. Here
a little after each strike, boring a hole into the rock was another hazardous task, as a stone could slip
suitable for holding explosive black powder. This from the chain and injure or kill someone as it was
drilling process was very dangerous and required the being hoisted out of the quarry. The chain was about
strict attention of the three men; otherwise, the man 12 feet long and made of half inch wire, with links
holding the drill could be seriously, even perma- two and a half inches across. “Sometimes that rockman
nently, injured by a blow from one of the heavy ham- had to use a rope to hang on to in order to put the chain
mers. around the stone secure.”
The fuse was then placed into the hole, fol- Slate-making itself was divided into three
lowed by the black powder. After the blast, the slate operations: block cutting, splitting and trimming.
had to be “cleaved” or split apart. The cleaves were As a rule, says Mr. Williams, there were three men in
ten or twelve inches in thickness, and if a piece of each group. The function of the block cutter was
stone was too large to handle, it was plugged — split very important in the production of roofing slate,
on a plane perpendicular to the layers and broken in requiring a great deal of experience. It was a job that
two. Plugging again involved drilling a hole by could wear a man down very quickly unless he knew
hand, although in this case only one man drilled the what he was doing. Blocks came out of the pit in
hole using a drill about two feet long with a single- irregular shapes and the block cutter had to make
hand hammer. This hole was not to be used for the blocks suitable for splitters to work. If the block
explosive powder, however, but instead a plug and needed to be split using a plug and feathers, the
feathers were inserted into the hole to force the block block cutter needed to measure for the proper place
of slate to split in two. to put the hole.
A “plug and feathers” is a set of tools consist- If the stone needed to be sculpted, then the
ing of two thin steel sleeves (the feathers) that slide block cutter had to use his gouge to cut a groove or
down either side of the hole, after which a tapered ditch in the end or side of the stone. From this
wedge (the plug) is forced between the feathers with groove, the block cutter cut into the block with a
62 The Slate Roof Bible — Chapter 5 — Vermont/New York
chisel in the direction he wanted. Then he had to Although it was a very arduous job, some men could
cleave the block (split it along the obvious splitting trim 10 to 15 squares of roofing slate in a ten-hour
plane) to make the pieces light enough to carry into day, amounting to about four to five tons of rock.
the splitting shanty. This was all done outside. The trimmers also had to shovel their rubbish as
A person referred to as the “splitter” sat in well as the splitter’s, and sometimes help the block
the splitting shanty. His tools consisted of a low stool cutter with his work.
to sit on, a wooden mallet with iron rings at both After trimming, nail holes were punched in
ends, and two or three thin, flat iron chisels about the slate. This was done by placing each slate, one at
three inches wide at the wide end, which were used a time, on a slate punch. A foot pedal operated the
to split out the individual pieces of roofing slate. machine which caused two sharp, metal punches to
The splitter (or “slitter” in Wales), sat on the stool poke nail holes in the slate about one fourth to one
and leaned the slate block against his leg with the third of the way down from the top and about an
smoothest edge upward. The block had now been inch and a quarter to two inches from the sides. The
split to a thickness of about one and a half inches by punch breaks out the back of the slate when it pokes
the block cutter. The splitter then split the block the holes through, and this breakage was advanta-
along the cleavage plane into two equal halves with geous as it allowed for the head of the nail to be
the hammer and chisel. A good piece of slate will countersunk into the slate. This kept the nailhead
split right into two halves with a good tap or two of from rubbing on the overlapping slate after being
the hammer. Each of the halves was again split in nailed to a roof, thus prolonging the life of the roof.
half, and so on, until the desired thickness of about A foreman kept a record of the production of
3/16 inch was reached. Naturally, some of the fin- each slate shanty, resulting inevitably in an atmos-
ished slate would be thicker or thinner, but for the phere of competition and rivalry between the shanty
most part, the finished slates were amazingly uni- crews when their individual rates of production were
form in thickness. Again, this craft required a lot of compared. The bosses encouraged these rivalries in
experience — some consider it an art. The splitter order to gain a greater level of production. In some
kept the unsplit blocks piled on his left side, and the companies, a group of about six men, known as a
“chips” (untrimmed slates after splitting) piled on slate gang, had the job of counting and piling the
his right on a small bench within easy reach of the slate and loading up the teams of horses.
trimmer. The mornings began with the whole gang in
A person known as a trimmer then took the the quarry carrying the previous day’s production
chips one at a time and trimmed them to make the out into the slate yard, before the pitman went into
largest possible size roof slate. The trimming was the pit. Because of the great weight of slate, this was
done by a trimming machine run by a foot treadle, heavy work, and the custom prevailed that there was
so that the trimmer had to hold and position the a ten-minute break after the slate was carried out.
slate with his hands while he operated the foot trea- The slate was then loaded onto wagons drawn by
dle at the same time. The maximum standard size of teams of horses and taken from the slate yard to rail-
a roof slate in the USA is 14” wide and 24” long, and road cars. Here the slate had to be packed into the
the standard sizes range down to about 6” wide by cars properly — they were stacked three high on the
10” long. In addition to these widths are 12”, 11”, long edge with wooden lath placed between the
10”, 9” and 8” wide slates of different lengths. rows. An article in the Granville Sentinel, dated

Nail holes are typically punched to allow for the nail head to be properly countersunk, as in the left illustration, below. Both “under-nailing”
(nail head protruding and rubbing against overlying slate) and “over-nailing” (nail head breaking through the nailed slate) will adversely affect
the longevity of the roof. Some manufactured slates with drilled holes do not allow for proper countersinking and should be avoided.

The Slate Roof Bible — Chapter 5 — Vermont/New York 63

 AERIAL CARRIER Aerial Carrier in Use
(Rides on cable between masts)

A. Frame
B. Cable Pulleys (Sheaves)
C. Detaining Sheave
D. Brake Wheel
E. Draw Rope Sheave
F. Billy Wheel
G. Billy Wheel Sheave
H. Shifting Bar
I. Shifting Bar Hook
J. Shifting Bar Lever
K. Brake Lever
L. Dumping Hooks
M. Turnbuckles
N. Cable
O. Detaining Rope
P. Draw Rope

t Masts and Aerial Carriers with Scrap Piles Below

SLATE 1) Chisel - For splitting

MAKER’S large blocks down to
TOOLS 5 workable size.
2) Mallets - For pound-
3 ing chisels.
3) Splitting chisels - For
splitting out individual
roof slate.
4) Gouge - For making
6 groove in slate block.
5) Plug and feathers -
For inserting into hole
to split block of slate.
6) Hand hammer - For
4 1 2 tapping plug and
s Ruggles Foot Powered
Drill and Slate Punch feathers into place.

64 The Slate Roof Bible — Chapter 5 — Vermont/New York

 Wooden Dump Car

Foot Powered Machine

for Drilling Slate

Slater’s Stake:
to aid in the
cutting of a
roof slate with
a slate ham-
The “Lightning” Slate
Slate Hammer: mer or slate
for cutting, ham- knife. Dresser punches
mering and holes in slate.
punching holes
in roof slate. Slate Ripper (center),
for removing slates
from a roof.

SLATER’S TOOLS

Ruggles Original
Slate Trimmer

Wooden Dump Car With Skip Ruggles Slate Car

The Slate Roof Bible — Chapter 5 — Vermont/New York 65

March, 1890, stated, “Charles Peck drew 24 and a half the rubbish stone. There was a demand for qualified
squares of 18 by 9 slate on one load from a Rising and men who could raise the mast, which was quite a feat
Nelson quarry to the station.” This load, weighing nine of engineering in those days, considering that the
tons, was probably drawn on a sled, and certainly stick may have been 200 feet long. The “tallest quar-
pulled by horses. During the first quarter of the 20th ry pole in the world” was 235 feet high, erected at
century, so much slate was being shipped out of Rising and Nelson’s Quarry #4 in 1908. A fellow by
Vermont’s slate valley that the Delaware and the name of Henry Vogel of Truthville was a pioneer
Hudson Railroad ran a freight train called “The in this business, and he was so highly regarded that
Slate Picker” primarily to pick up loads of slate. his services were in demand — and he accomplished
Eventually, all of these slates ended up on someone’s them even after he became handicapped in one leg.
home, barn, garage, church, grange hall, carriage The sticks as a rule were native green pine
house or other building. made of two or three poles spliced together to form
In 1889, the going price for a square of slate one piece. The splices were made of eight-inch
was around $3, while the average pay of a quarry square oak timbers about sixteen or twenty feet long,
worker was about $25 per month. In 1890, one slate bolted to the stick. A cable, two guy wires, plus “sad-
company sold 170,000 squares of slate, enough to dles” and “sheaves” (pulleys) had to be attached to
cover 14,000 roofs, weighing more than 10 million the top of the mast before it went up. All of this
pounds and requiring 3,400 freight cars to haul to together made for quite a heavy burden, and raising
market. The peak of slate production in the slate val- it was extremely difficult. One mistake and it could
ley occurred in 1927-28, when a square of roof slate come down in pieces, and the work of a team of men
went for around $15, compared to about $350 today. who had toiled for days would be lost. One can still
Often a horse provided the power to hoist see the old masts standing tall among the scrap slate
stone out of the quarry, but as the pit got deeper, a piles in Vermont today.
steam boiler and engine were used. Eventually, an A- The cables were strung high in the air from
frame supported a cable that extended across the pit, mast to mast, and the aerial carriers rode on the
and a carriage was hung on the cable. The carriage cables. Despite their height, these carriers could
was attached to the engine with a wire rope, reach into the deepest pit by dropping a box
enabling the power of the engine to pull the carriage attached to another cable. The slate block or rubbish
along the cable. The carriage could be brought to a could then be loaded onto this box and raised up out
stop by bolting a wooden block on the cable, and this of the pit, moved along the cable, then let down near
stop was located near where the men needed to the splitting shanties (if a slate block) or dropped
unload stone or rubbish boxes. The slate blocks and into the dump (if rubbish). All this was done by the
rubbish boxes were put on a small railcar; the blocks engineer, who operated the aerial carriers, perhaps
were rolled to a shanty while the rubbish was rolled three at one time, powered by a steam engine.
to the dump. Eventually, a self-dumping carriage Electric power came into the slate valley in
was invented by a blacksmith in Poultney, Vermont, 1913. Eventually, air-powered jack-hammers came
and it came into universal usage in slate quarries in into use for cutting slate, and these could drill a hole
a very short time, bringing with it a brand new job. in a slate three times as fast as a man could by hand.
The self-dumper saved a great deal of human labor Around 1919, trucks began to be used to haul slate to
as the engineer could stop the carriage anywhere the railroads; the first ones had hard, solid tires.
along the cable and set the block down in a conven- The early work forces involved in the sea
ient location for it to be worked on. green quarries were of Irish and Welsh nationalities.
As the pits got deeper, they began to fill with These people learned the trade of slate quarrying in
water creating a nuisance that had to be pumped Wales and emigrated to the United States, both as
out. The water was not wasted, however — it was skilled workers and common laborers. Toward the
pumped to the boiler house to be used to make end of the nineteenth century, Eastern Europeans
steam to power the steam engine. began to emigrate to Vermont to work the quarries,
A very high mast, or stick, was needed in and by the turn of the century, the Eastern
order to use these carriages. The masts varied in Europeans came in large numbers. Italians soon
length from less than a hundred feet to over two joined them in the quarries and also became very
hundred feet tall, depending on the topography of good at rock work. There was only a sprinkling of
the land. They had to be located four or five hundred other nationalities working slate in Vermont.
feet from the edge of the pit to allow for dumping of These four ethnic groups did not mix social-
66 The Slate Roof Bible — Chapter 5 — Vermont/New York
 s Clark Hicks, president of the Evergreen Slate Company (2003) in Granville, NY, gives the author’s wife a tour of one of
Evergreen’s roof-slate stockyards. Roof slates are trimmed down to size in an Evergreen Slate Co. trim room (right).
Photos by author.

ly, except perhaps to share a drink at a local bar. ing. One man was found alive the next day after
Each had different religions, which created the main being buried for 24 hours, but died the following
social barrier, as each group’s church provided their night from exposure.
social center. The Welsh were Protestants and the Another incident occurred in the spring of
Irish and Italians were Catholic. The Eastern 1916. The quarry was situated such that the engineer
Europeans had their own church and fraternity. who operated the steam engine and dumped the rub-
Throughout the history of the sea green bish from the aerial carriers onto the dump pile,
quarries and up until the 1930s, there were no health could not see the top of the dump. The quarry boss
or safety regulations. There were also no public con- saw a slab of slate on the dump which he thought
veniences available to the workers. The men had to should have been worked into slate shingles, but the
provide their own drinking water “any way they could block cutter disagreed. The two of them proceeded
get it, and sometimes under very unsanitary conditions, in to argue over the block while standing in the dump,
some cases melted ice water from some hole under an old not hearing the familiar sound of the rubbish box
dump which would dry up when the hot weather came.” approaching overhead. The engineer dumped the
Slate quarrying was a hazardous occupation rubbish right on top of them, not aware that the men
due to the cleavage of the stone and the different were standing on the rubbish pile; both were killed.
natural cuts and joints. Undermining was a common From then on, the engineer gave two blasts of the
cause of accidents, as was carelessness and faulty quarry whistle as a warning when the rubbish was
equipment. The use of black powder and dynamite about to be dumped.
added to the perilous nature of this trade. There was The lack of worker’s compensation during
no workers’ compensation, nor were there safety those days made for some tough times for families
inspections in the early years. The responsibility for that lost a family member to death or injury. A cus-
safety rested upon the shoulders of the operators and tom prevailed in which men could pledge money to
supervisors. be taken directly from their pay to benefit those
As a result, accidents were frequent, and it unfortunate families. This money went directly to
was not uncommon for a man to be killed or maimed the affected families, with no deductions taken from
for life. In 1903, for example, eleven men were killed it.
in a cave-in at the Vermont Slate Co. Quarry, locat- Today’s slate quarries are a world apart from
ed near the Warren Switch section of the sea green the old mines that produced the slates for most of
quarries. A section of ground where slate was stock- the older roofs in America. Modern quarries are
piled and where the part-owner of the quarry, Mr. much safer, and the workers are protected by insur-
Williams, happened to be standing, was undermined ance and other benefits. They now use diamond
and collapsed, taking Mr. Williams down and piling saws, forklifts, trucks, bulldozers, highlifts and
the slate on top of him. In another accident in 1910, other modern equipment. The one operation still
five men were killed in a cave-in in the Owens done by hand, however, is the splitting of the slate,
Quarry on Briar Hill, again the result of undermin- still achieved by hammer and chisel.

The Slate Roof Bible — Chapter 5 — Vermont/New York 67

Vermont’s famous colorful, durable roofing slate is abundantly available new from a variety of slate companies. Above left, Craig Markcrow of
Vermont Structural Slate Co., in Fair Haven, VT, points out the cleavage line on a slate block. Above right, David Thomas of Hilltop Slate, Inc.
in Middle Granville, NY, inspects their stockyard. Below left, Jonathan Hill of Greenstone Slate Co. in Poultney, VT, examines slate blocks that
are awaiting final splitting, and below right, Chuck Smid of the New England Slate Co., Pittsford, VT, demonstrates the impeccable production
characteristics of their North Country Black from Quebec. For a full listing of Vermont slate suppliers see page 295.

68 The Slate Roof Bible — Chapter 5 — Vermont/New York

 NEW ROOFING SLATE IS READILY AVAILABLE TODAY FROM VERMONT SUPPLIERS
Top left: Shawn Camara of Camara and Sons Slate Co., in Fair Haven, Vermont, inspects a pallet of new, extra-thick roof slate. Top right: Steve
Taran of Taran Brothers Slate Co. displays an unusually large mottled purple roof slate. Large sizes and thick slates are readily available from
Vermont producers. Bottom left: Stephen Williams of Rising and Nelson Slate Co. in Middle Granville, New York, inspects a pallet of unfading
green roof slate. Bottom right: Wm. Drew Turner, president of U.S. Quarried Slate in Fair Haven, Vermont, observes his quarry pit where some
of the famous Vermont “unfading” slate originates. For a complete listing of Vermont/New York slate suppliers see page 295 or visit jenkinss-
late.com on the internet.
Photos both pages by author.

The Slate Roof Bible — Chapter 5 — Vermont/New York 69

 Chapter Six

PENNSYLVANIA SLATE
“When the ribbon turns toward the mountain, that’s the best slate.”
Randy Rowe

P
ennsylvania slate quarries exist in two the Peach Bottom district in York and Lancaster
districts. The largest, most productive counties, which straddles the Pennsylvania and
and well known of these is the Maryland border along the Susquehanna River near
Lehigh-Northampton district, which extends about Delta, PA (see map, next page). This slate deposit is
thirty miles from Slateford in the north on the 10 miles long and may be nearly a billion years old.
Delaware River, to beyond Slatington in the south Peach Bottom slate has a higher degree of metamor-
on the Lehigh River, including the quarry towns of phism and is higher in silica, making it a harder,
Bangor, Pen Argyl, Belfast and Chapman, among more durable slate than the average Lehigh-
others. The slate belt here is about five miles wide, Northampton slate. In fact, Peach Bottom slate was
lies on the south side of the Blue Mountain, and may once considered “the best slate in the world,” but is
approach 500 million years in age. Approximately now no longer quarried. Peach Bottom slate will be
90% of the slate produced in Pennsylvania came discussed in greater detail in the next chapter.
from this district, which is still productive today. Pennsylvania has long been the nation’s
It should be noted that this slate deposit leading producer of slate. Although at least ten
extends into New Jersey, and slate quarries have states were producing slate as late as 1944,
been operated near Lafayette, in Sussex County, Pennsylvania’s slate production averaged 40-50% of
New Jersey by the Lafayette Slate Mining the nations output during the first four decades of
Corporation of Port Chester, NY. However, as the the 20th century. Today, however, slate production
New Jersey productions were dwarfed by the has markedly declined, not only in Pennsylvania,
Pennsylvania productions and are not in operation but also throughout the other slate-producing
today, the New Jersey slate deposit will be consid- regions of the U.S. This is due to the market compe-
ered in this book as equivalent to the Pennsylvania tition of synthetic roofing materials, as well as the
slate of the Lehigh-Northampton district. tremendous amount of work, and waste, involved in
The second slate district in Pennsylvania is slate quarrying. Some estimates put the amount of
s

Slate block being hoisted to the surface, probably in a Pennsylvania mine, illustrating the degree to which quarry work-
ers may be exposed to overhead hazards. [Source: United States Department of the Interior, Bureau of Mines Report of Investigations 9009, 1986; p. 7.]

The Slate Roof Bible — Chapter 6 — Pennsylvania 71

 originated at the famous Peach Bottom quarries.
Other Pennsylvania slate comes from the “hard
vein” belt, which occurs near Chapman and
Belfast, and which falls somewhere between soft
and hard on an overall durability scale. Then
there is the “gray-bed” slate, which is not as
durable as Peach Bottom, but may be consider-
ably more durable than the Pennsylvania soft
slate.
Unlike Maine slate, which is commer-
cially one primary type of black slate,
Pennsylvania’s vast slate deposits produce many
types of slate with many characteristics, although
all are black (or close to it) and may not seem
very different in appearance to the layperson. As
mentioned in Chapter Two, the main slate
Pete Papay (right) of the Penn Big Bed Slate Company in Slatington, PA, deposit in eastern PA, which produces primarily
producer of Pennsylvania’s well-known black slate and importer of for-
eign roofing slates, discusses block-cutting strategies with his diamond soft slate, is 2,800 feet thick, two to five miles
saw operator prior to sawing a huge block of PA slate rock. wide, and thirty miles long. This is such a mas-
Photo by author.
sive mineral deposit that considerable variation
waste rock in slate quarries at 70-90% before the can occur throughout its range. In the Pen Argyl
invention of the wire saw in 1926, which subsequent- region, for example, the following slate runs appear
ly enabled slate to be cut more efficiently. In 1985, a in succession: the Pennsylvania Run, United States
full 65% waste was still generally considered accept- Run, Diamond Run, Albion Run, Acme Run and
able in the Lehigh-Northampton district. Due to the Phoenix Run, each run bearing a slate of a different
decline in business, many quarries have shut down, quality, although the difference may not be signifi-
and entire regions now lay idle. cant. The runs are separated by intervening beds, 75
Some slate regions adapted to the decline in to 280 feet thick, of unworkable slate-like rock.
demand for roof slate by producing slate granules Each run is itself then separated into indi-
for asphalt shingles. Nearly a million tons of roofing vidual beds. The Albion Run, for example, consists of
granules were produced in 1942, for example, and 12 beds combining to form a total run thickness of
ground slate was also put to use as an industrial 184 feet. On a visit to the PA slate quarries in July of
abrasive, as a filler in paints, asphalt mixtures, roof- 1993, the author came upon an old list naming the
ing mastic, oilcloth and other products. Slate has veins of the Albion run. A quarry worker had evi-
other uses, including billiards tables, blackboards dently scrawled the list in pencil on a piece of card-
and for structural purposes, and Pennsylvania has board and tacked it to the wall of an old slate shan-
been the nation’s leading producer of these slate ty, long since abandoned when I stumbled upon it.
products. After blowing the dust off the cardboard, I found a
The slate of Pennsylvania is primarily black full 43 veins listed, each with a colorful name either
or dark gray. In the slate industry much of the PA pertaining to the qualities of the slate in that vein, or
slate is known as “blue-black,” as it looks slightly honoring a friend or family member.
bluish when first quarried. It ranges in durability If you’ve read Chapter Two of this book, you
from soft (S2) slate with as little as a 50-year lifes- understand how slate was formed and realize that
pan, to an extremely hard (S1) slate with a lifespan the rock was originally clay which settled under
that may approach four centuries or longer. water in layers over periods of millions of years.
The vast majority of the Pennsylvania slate Because of the immense amount of time it took for
quarried for roofing is soft black slate with a life those layers to form, they were subjected to different
span on roofs ranging between 50 years and 125 environmental factors over time, and today those
years, originating in what is known as the “soft vein” layers of finished slate will show different character-
region of Lehigh and Northampton Counties. This istics as one digs deeper into them. As a rule, the
region includes Bangor, East Bangor, Pen Argyl, deeper the slate, the older it is and the harder and
Danielsville, Slatington and Slatedale. Only a rela- more durable it is (providing that the slate deposit
tively small amount of slate from the Keystone State hadn’t been heaved upside down by geological
72 The Slate Roof Bible — Chapter 6 — Pennsylvania
forces). This is one reason why Peach Bottom slate
is more durable than the softer slates farther north
in the PA slate belt. It is geologically much older.
In any case, the list of slate veins in the
Albion Run near Pen Argyl, PA, provides an excel-
lent illustration of the variation that can be found
as one digs deeper into a PA slate deposit. When
one understands that black slate from one quarry
can have a variety of characteristics depending on
the vein in which it was found, then it is easy to
understand how difficult it may be to pinpoint the
exact origin of a slate currently serving on the roof
of a house. If you have a soft black slate on your
building, then you can be pretty sure it is from The production of roofing slate in the United States dropped dra-
matically during WWI, never fully recovering. Pennsylvania has
eastern PA. Yet some black slate from PA is hard. produced much of the roofing slate in the U.S., although relatively
And some slate from PA is gray and hard. It is the little Peach Bottom slate was ever produced.
[From Slate in Pennsylvania, p. 112]
hardness of the slate that we are interested in, as a
hard slate roof can be restored when old, but a soft
slate roof must be replaced. Many thousands of
roofs have PA slate on them, but exactly where in
PA those slates came from may be difficult to say.
There are some exceptions to this, however.
The first, of course, is that if you live near
a slate quarry, you are likely to have that slate on
your roof. If you live in Chapman, PA, you proba-
bly have a Chapman slate roof. Same for the Peach
Bottom area (Delta, PA, for example) — you have
a Peach Bottom roof. In Bangor, PA, you probably
have a slate on your roof from the Bangor area. The production of roof slate peaked in Pennsylvania around 1902,
However, all of these slates, and many others from with the bulk of the production occurring between 1896 and 1915.
Production continues to this day, and the deposits remaining in the
PA have been shipped all over the eastern seaboard ground have barely had their surface scratched. Many homes were
of the United States during the last century. And if built during that period of peak production, and many had (and still
have) PA slate on their roofs. [Source: Mineral Resources of the United States
you don’t live near a slate quarry and you think and Minerals Yearbook (dates unknown)].
your roof is a PA slate roof, how do you identify it?
Peach Bottom roof slate is easily identifi-
able because it is quite black, remains smooth (non-
flaky) with age, and stays very hard. It also has a
characteristic sheen to it that may not be evident
unless you look at the back of the slate (assuming
the front of the slate has been environmentally
stained over time).
Chapman slate is easily identifiable
because it is black, somewhat hard, and has diago-
nal bands (ribbons) across the full width of the
slate that are evident from a distance — you can
see them from the ground if the slates are on a
roof.
Bangor black is a uniform black, smooth
SLATE ROOFING RECEIPT, 1876
slate with no apparent ribbons, and is fairly soft, FOR APENNSYLVANIA BLACK SLATE ROOF IN PHILADELPHIA
but can still last a good century. With age, these Philadelphia, October 7, 1876, Levi Stokes, Dr. to True Blue Slate
roof slates will appear to become flaky and will Co., for roofing house with slate. 3,444 ft @ 8 1/4 = 284.13, 41
gutter hooks @ 20 = 8.20 (total = $292.33), rec’d payment,
crumble. Many of the older Bangor slate roofs are True Blue Slate Company, Booth (?)
reaching the end of their years at 75- 90 years old,
The Slate Roof Bible — Chapter 6 — Pennsylvania 73
 and many have already worn out. Bangor slate was
shipped with a “Genuine Bangor Slate” label which
some roofers left stuck to the slate when they
installed the roof, so when the roof is removed 80
years later, the label is still on the back of the slate,
allowing it to be readily identified.
Pen Argyl black slate may develop a light
brownish surface color due to iron in the slate, and
will also become flaky with age. In some cases, these
slates can look remarkably similar to some old
Vermont sea green slates to a layperson. People may
point out old Pen Argyl slate roofs and mistakenly
identify them as sea green roofs simply because of
the “rusty” surface color that has developed over the
years. When Pen Argyl slate gets old, however, it will
be visibly deteriorating and individual slates will be
seen falling apart on the roof. The pieces that fall to
the ground will probably have soft edges, soft
enough to crumble in your fingers. Old sea green
slate, although changing to a brownish color, doesn’t
A. J. Williams of Williams and Sons Slate Co. in Wind Gap, PA, is a turn soft so quickly.
manufacturer of Pennsylvania’s famous roofing slate. Williams also
imports and sells premium roofing slates from selected foreign Some of the soft black slates from this region
sources. exude a chalky substance over time and may eventu-
Photo by author.
ally display a whitish hue, especially around the
edges.
Slate from the “gray beds” of eastern PA
seems to be among the most admired for durability,
second, perhaps, only to the Peach Bottom slate.
They are fairly rare, “olive green in color” according
to one published source, but to me look dark gray
(but not completely black), and contain little car-
bon. When carbon makes up the bulk of the “rib-
bon” in ribbon slate, it greatly reduces the life of a
piece of roofing slate, which may be one reason why
gray slates last so long in comparison to their black
cousins. In fact, the gray-bed slates of PA are said to
resemble the green slate of Vermont in chemical
WIRE SAW FOR CUTTING
SLATE IN QUARRY PIT composition.
The first slate quarry in Pennsylvania’s
Lehigh-Northampton district opened in 1812 at
Slateford in Northhampton County, according to
one source. Another source claims the first quarry
Cutting End
was opened in 1832 by Samuel Taylor and actively
Driving End operated from 1836 when James M. Porter joined
him as partner. This occurred before railroad service
existed into the area, and the slates were sent down
the Delaware River on boats. This quarry only last-
ed about 30 years.
Another quarry near Slateford, the Snowden
These saws became an essential part of the slate quarrying indus- Quarry, opened in 1870 and operated until 1917,
try in Pennsylvania in 1928, yielding a more efficient quarrying
process with less waste.
when it was deemed a non-essential war-time indus-
[From: Bowles, The Stone Industries, 1934, p. 256] try, and closed. During World War I, many quarry
workers went to the steel mills for war production,
74 The Slate Roof Bible — Chapter 6 — Pennsylvania
 WHITE SPAR
NAMES OF VEINS IN THE ALBION RUN, PEN ARGYL, PA BALDWIN
The top of the list is closer to the earth’s surface. Names are printed as hand written (the list LISA WEEKS
was found in an abandoned quarry shack). At the bottom of the list is a question mark to indi- JACKIE WEEKS
cate that the men didn’t know what they’d find as they dug deeper. SALLY WEEKS
JENNY WEEKS
SMALL WASTE BEDI
SAM AND CELESE - HARD 24
and many quarries closed and never reopened.
LITTLE 5’
Slate was discovered in the Bangor area on a 24 BED
farm at what is now East Bangor, by Joseph Kellow GRANNIE RAINS + 3 FOOT
in 1853. This quarry was operated from 1855 by fel- BIG 5’
SARAH BRUCH
lows named Weidman and Derrick. HARD BIG RED
Bangor got its name from Robert M. Jones, a WASTE BEDI
pioneer in the slate industry in the Bangor commu- ROUNDY BACK/GLDN. EAGLE
SAM BRAY
nity who took the name from his hometown of BLACK BED
Bangor, in northern Wales. Jones opened the Old WASTE BEDI
Bangor Quarry in 1863, and the town that sprung up HANEY & ELLEN/HARD BED
THREE BEDI
around it took the same name. Once again, the WASTE BEDI
Welsh played the role of slate entrepreneurs, found- LITTLE BIG BED
ing an industry in Pennsylvania from which entire BILL BUDGE
VAN JULIA/MILK & WATER
communities emerged. STRAIGHT BEDI/BOB CORY
Some of today’s PA slate quarries are huge, JOHN WELTY & FAMILY
neatly cut holes that plunge vertically into the earth WASTE BEDI
WILCOX & JAN DENTITH
for hundreds of feet. The abandoned quarries of this JOHNNIE NACK
type have vertical cliff-like walls dropping as much CARBUNCLE & SILVER 24
as 650 feet to a pool of water at the bottom. These LITTLE 18 BEDI
TWO 24 & 24 BED
can provide quite a hazard for persons out for a
WASTE BEDI OF GRAY
stroll in the woods unaware of the one-way drop BLUE END
awaiting them should their foot slip at the edge of GRAY BED
WASTE BEDI
one of the abandoned pits. Local folks tell of deer
GENUINE 24 & RIBBON BED
inadvertently dropping off the edges on a one-way 2 LENGTH BEDI
free-fall to a watery grave. Fortunately, accidents are GENUINE BIG BED
24 + HARD TWENTY
not common despite the unfenced holes (knock on
TWO COLOR RUN
wood). FRONT BIG BED
One advantage to deep pits is that the tem- BASTARD RUN
perature remains a steady 55 degrees Fahrenheit at ?
the bottom where the workers toil daily to wrestle
s Example of thickness measurements in beds in PA. Diagram rep-
out the slate slabs. This provides a relatively cool resents 71’ of depth. “lt.” = light, “sdy” = sandy [From Slate in Pennsylvania]
work site in the summer and a relatively warm one
in the winter. The splitting of slate into the right thickness
for roofing shingles may not entirely be the respon-
CONVERTING SLATE BLOCKS sibility of the splitter, but may involve the block cut-
INTO SHINGLES ter and the blacksmith. The block cutter can split
the incoming block to the proper thickness to allow
The slate in Pennsylvania is still split into for a predetermined number of slates to be produced
roofing shingles by hand, and the blocks are kept from one slab. Since the standard thickness of a
wet with water during the splitting process to roofing slate is 3/16”, the slab should be a factor of
enhance the ease of splitting. The stone is said to that thickness. In order for the block cutter to con-
split “with much greater ease if the quarry sap is not sistently split a block to the thickness desired, his
allowed to evaporate,” an opinion echoed by slate chisel is conveniently made to the proper width and
workers in Wales and elsewhere in Europe, who can be used as a measuring tool as well as a chisel.
insist that slate blocks left out on the surface of the So the blacksmith is instructed to forge out a chisel
earth to dry will not split as readily as freshly quar- that the block cutter can use to measure his cut. In
ried slate. this manner, the slate splitter (the guy who splits out
the actual roofing slates) receives blocks that have
The Slate Roof Bible — Chapter 6 — Pennsylvania 75
 already been split to a a roof onto a concrete driveway without breaking, as
convenient size, which long as they land on edge.
he then splits by eye The final trimming of the slate shingles was
through the center, commonly done using a foot-powered trimmer with
then in half again, then a straight, steel cutting blade about three feet long.
again to end up with The outer end of the blade was attached to a spring.
the finished pieces of Another type of trimmer had a rotary blade like an
3/16” roofing slate. old-fashioned push-type lawn mower. Although
Naturally, this tech- these machines were once powered by foot or hand,
nique is not precise and today they’re electrically powered.
some slates turn out to Each slate shingle was laid against a steel bar
be thick or thin. on the trimming machine when it was trimmed, the
However, the finished bar being marked in inches so that the trimmer
slates shipped out from could trim the slate to the standard sizes, ranging
the slate yards in the from 6”x10” to 14” x 24”. The person trimming the
old days were amazing- slate could easily estimate by eye the largest possible
ly uniform when the size for each untrimmed piece, and trim according-
shingles were split from ly. Once trimmed, the slates were stacked in piles
a good quality slate — sorted by size, then handed to a person who had the
the better the quality, job of punching the nail holes in the slate. The holes
the easier it is to split a were punched into the back of the slate (the side fac-
thin shingle. When ing down against the roof) due to the countersinking
stacked, one can rou- effect of the hole punch, which then enabled the nail
tinely expect 50 slates heads to sit flush into the slate. Two men on a good
per foot of row of slates day can split and dress 12-14 squares of slate, if they
that are standard 3/16” have nice blocks to begin with.
thickness. This figure
(50 slates per foot of CHAPMAN SLATE
row) is close enough
that a person who has a It is worth mentioning the Chapman quar-
stack of standard ries, which are located (you guessed it) in Chapman,
antique American PA. The quarries are no longer in operation, but they
slates need only meas- were once considered the most productive producers
ure the total length of of PA “hard vein” slate which are still serving thou-
the rows, in feet, and sands of roofs today. This black slate has a distinc-
multiply by 50 to get a tive appearance because it is adorned with many rib-
close estimate of the bons, or bands of various shades of black that cross
number of slates (10 the face of the slate at an angle, giving the slate a
feet of slate shingles striated appearance. These ribbons are fairly hard
stacked tightly on edge and do not disintegrate as readily as the carbon rib-
will amount to 500 bons common to the “soft vein” slate of
slates, for example). Pennsylvania. I have seen many hundred-year-old
And slate should be Chapman slate roofs still in fair shape, as these
stacked on edge on slates are one of the harder and more durable of the
boards or slats, and not Pennsylvania black slate.
piled in flat, vertical The Chapman Slate Company was one of the
piles like dishes, as the oldest producers of slate in Northampton County,
weight of flat stacks can with the Chapman Standard Quarry opening in
weaken and break some 1860, and producing primarily roofing slate and
of the slates over time. slate slabs. Several other quarries operated in the
Roof slates are amaz- Chapman vicinity. The “Chapman” Quarry consist-
ingly strong on edge, ed of two large holes separated by a wall of rock
and can be thrown from about 50 feet wide, the west hole being 450 feet long,
76 The Slate Roof Bible — Chapter 6 — Pennsylvania
300 feet wide and 130 feet deep, while the east hole
is about the same width but is about 1,000 feet long,
and 150 feet deep, rivaling the largest quarries in the
Bangor and Pen Argyl districts in volume. The old,
abandoned quarry pit still lies just outside
Chapman, PA, today, and probably won’t be going
anywhere soon. There was still some quarrying
reportedly taking place there in 1924, and in 1931
the Chapman Slate Company was still listed as a
slate producer in Pennsylvania. Today, however, no s Slate blocks hoisted out of the Dally Slate Company quarry pit
quarrying is taking place there and Chapman roof lay stacked and waiting in the modern slate mill. The edges have
been sawed on a diamond saw. Some of these blocks will be used
slates cannot be bought new. for structural slate, some for roofing.
On the other hand, Chapman slates are one
type of black Pennsylvania roof slate that are recy-
clable, and care should be given to remove these
slates from roofs of buildings being demolished or
re-roofed so the salvaged slate can be used to keep
existing Chapman roofs in good repair. Otherwise, if
recycled Chapman slates are not available, almost
any black Pennsylvania slate can be used to repair a
Chapman roof, so long as the slate is sound,
although no slate will match the roof quite as well as
a genuine Chapman slate.
It should be noted that the slate in s Chapman slate roof, good condition. Note “ribbons” running
Pennsylvania seems to become harder and more across the face of the slate at an angle, which is a distinctive charac-
teristic of Chapman slate. Chapman ribbons tend to be hard, and
durable as we move farther south in the state. When don’t undermine the quality of the slate. Chapman slates, first quar-
we arrive at the border between Pennsylvania and ried around 1860, were the most productive of Pennsylvania’s “hard
Maryland, we find a black slate so hard and durable vein” slates. If cared for, these roofs can last well over 100 years.

that it is considered by many to be the best slate in All photos this page by author.

the world, as we shall see in the next chapter.

s Boro Hall of Chapman, PA. The town is not much bigger, but it
is home to Chapman slate, although the quarries are no longer in
production. The “hall” has a Chapman slate roof.
s

House near Chapman, PA, sided (and roofed) with Chapman slate.

The Slate Roof Bible — Chapter 6 — Pennsylvania 77

 s Slate block being hoisted out of quarry en route to the mill where it will be split down into roof slates.

t If roof slates are more expensive than the more commonly mass-produced, artificial roofing materials of today, then one sure reason is the
hand-made nature of the material. Each piece of roofing slate is hand split from solid rock (below left), hand trimmed into the appropriate size
and shape (below right), as shown at Dally Slate Company in Pen Argyl, PA, and then hand punched for nail holes (below center).

Photos by author.

78 The Slate Roof Bible — Chapter 6 — Pennsylvania

A block of slate is being hoisted out of a slate quarry near Pen Argyl, PA, appearing as a light colored rectangle in
the top center of the picture. The circle near the bottom of the photo indicates a quarry worker, dwarfed in this 350’
deep, vertical-walled hole. The photo on the previous page shows the block emerging from the top of the pit. It will
be taken into the mill where it will be cut and split to size, yielding PA’s characteristic black slate.
Photo by author.

The Slate Roof Bible — Chapter 6 — Pennsylvania 79

 Chapter Seven
PEACH BOTTOM SLATE
Pennsylvania/Maryland Slate District
Professor Agassiz (late 1800s) “The Almighty might have made a more perfect fish than the trout, but he never did.”
Mr. Humphrey (quarryman) “I say the same for the Peach Bottom slates.”

W
hat intrigued me most about Peach Peach Bottom slate
Bottom slate was its mystery. In was no longer in pro-
nearly three decades of working on duction and could not
slate roofs I had never seen a Peach Bottom slate (or be bought new on the
so I thought) and hadn’t a clue about what one roofing market.
looked like. One day someone phoned me and told Furthermore,
me he had some roof slates for sale. This was a guy modern maps of
just five miles down the road who described the Pennsylvania show no
slates as “really nice, beautiful Peach Bottom slate.” town named Peach
I drove to his country home to look at the slate and Bottom. However, I
sure enough, there lay a pile of really nice slate in happened to have an
his front yard, neatly stacked, with scalloped bot- old map of
toms. They were a light gray slate with a reddish cast Pennsylvania, and it
to some of them, which I recognized as sea green did show a tiny little
slate from Vermont. I didn’t buy them because the place named Peach Bottom just north of the
guy wanted too much money, but I wondered how he Maryland border on the east bank of the
came to the conclusion they were Peach Bottom Susquehanna River. So one day I couldn’t stand it
slates. Apparently, he thought the color was peachy. any longer, and I set out for the spot on the map, a
In my wanderings through the slate regions full eight hours drive from my home in western PA.
of Vermont, New York and Maine, I came upon old I was determined to find the truth about Peach
books about slate production in the United States, Bottom slate once and for all. I dragged a couple of
and Peach Bottom slate was mentioned as being of my kids with me to keep me company, and one July
the highest quality, lasting hundreds of years. This morning we took off. We drove all day until we
was hard to believe as reached a campground
most of the slate from in Maryland just across
Pennsylvania is soft and the border from PA,
relatively short-lived where we pitched a tent
compared to the harder and got a little bit of
slate from Maine, sleep under the starry
Vermont, New York and night sky. The loud ser-
Virginia. The notion enade of summer’s noc-
that Pennsylvania, with turnal creatures kept us
all its soft slate beds, awake for a while. My
could also be the source fifteen-year-old daugh-
of a slate so hard and ter’s comment was, “I
durable as to deserve wish those birds would
such high regard by shut up!” “Those are
authors of pre-1900 tree frogs,” I said, “Go
books only added to the to sleep.”
mystery. This was com- Road sign near Delta, PA, on the Maryland Early the next morn-
pounded by the fact that side of the PA/MD border. ing we drove the back

Opposite: Peach Bottom slate graces barns as well as elegant masterpieces of architecture, such as the Castle Park Apartment Complex in
the St. Louis, Missouri area. This roof was 120 years old in 2001, and the slates were nearly perfect. Photos by author.

The Slate Roof Bible — Chapter 7 — Peach Bottom Slate 81

roads to the dot on the map named Peach Bottom. the quarries themselves. He did have a pile of slate
We found one or two houses and a boat marina on in his back yard matching the solid black slate on
the east bank of the Susquehanna, right across the the roof of his house, so I bought a few. “This house
river from the Peach Bottom nuclear power plant, was built in the 1700s,” he said. “See that roof? That
which loomed on the opposite bank like a behemoth, Peach Bottom slate is just as good as the day it was
its high-powered electrical transmission wires ema- put on.”
nating from it, octopus-like, in every direction. This The slate itself is coal black and very hard,
didn’t look like a place for a slate quarry, in my opin- with a sheen to it that I had not seen on any other
ion, but I did notice that the name of the road going black slate. I passed roofs with these slates on the
uphill past the marina was Slate Hill Road. “Let’s drive to Peach Bottom, seeing more of them as I got
follow this road,” I said to the kids, excited, like a closer to my destination and wondering if they were,
bloodhound on a trail. in fact, the elusive Peach Bottom slate. I had not
At the top of the hill, we passed an old farm seen any slate like this back in western PA (although
with slate roofed buildings. We then came upon a once I learned to recognize them, I did occasionally
small, old house, also with a slate roof, where an old see them back home). The most striking characteris-
man was roto-tilling his garden out back. I pulled tics of these slate roofs were the darkness of the
over and shut off the car motor. The old fellow black color and the shiny gleam.
turned off his roto-tiller and we met in his side yard. The kids and I set out in the van for the
“I’m looking for the old Peach Bottom slate wooded hill in the distance. We found a dirt tractor
quarries,” I said, after introducing myself. “Do you road leading up to the woods, and there we pulled
know anything about them?” off and set out on foot. The air was hot and muggy
“Why sure I do. What do you want to know?” and puddles littered the lane, which was all but
“Where are they?” washed out from recent heavy rains. We were sweat-
The fellow turned around and pointed off ing by the time we got to the top of the hill, proba-
across the green fields of corn and hay to a patch of bly a half mile walk between corn fields and hay
trees on top of the hill we had just driven by. “Back fields thick with huge butterflies. We stopped under
there in those trees you’ll find a giant electrical transmission tower on a bluff over-
the old slate piles.” I looking the beautiful Susquehanna River. The
Read this in
bed if you suffer pumped the friendly man nuclear power plant was now directly opposite us,
from insomnia. for more information, but connected to the tower by electrical lines hanging
he didn’t know much about across the water, cracking and buzzing menacingly
over our heads. My hair all but stood on
ANALYSES OF PEACH BOTTOM SLATES end. From our vantage point I could see
FROM FIVE DIFFERENT QUARRIES (%) a mountain of slate rubble lurking in the
trees across the corn field, so the kids
and I wove through the rows of corn to
1 2 3 4 5
get a closer look. When we reached the
SiO2 . . . . . . . . 55.88 . . . . 58.37 . . . 60.32 . . . 60.22 . . . . 44.15 edge of the woods I plunged into a forest
TiO2 . . . . . . . . . 1.27 . . . . tr. . . . . . . n.d. . . . . n.d. . . . . . . n.d. of poison ivy, wading through it to get to
Al2O3 . . . . . . . 21.85 . . . . 21.99 . . . 23.10 . . . 19.56 . . . . 30.84 the slate pile. The kids were wearing
FeO (Fe2O3) . . 9.03 . . . . 10.66 . . . . 7.05 . . . . 5.24 . . . . 14.87 shorts so I cautioned them to stay out of
CaO . . . . . . . . . 0.16 . . . . . 0.30 . . . . ---.--- . . . . 3.87 . . . . . 0.48 the woods and go back to the van and
MgO . . . . . . . . . 1.50 . . . . . 1.20 . . . . 0.87 . . . . 2.30 . . . . . 0.27 wait for me there.
K20 . . . . . . . . . . 3.64 . . . . . 1.93 . . . . 3.83 . . . . 2.90 . . . . . 4.36
I climbed the huge pile of scrap slate
Na2O . . . . . . . . 4.46 . . . . ---.--- . . . . . 0.49 . . . . 2.15 . . . . . 0.51
like a mountain goat and stood on top of
CO2 . . . . . . . . . n.d. . . . . . 0.39 . . . . n.d. . . . . n.d. . . . . . . n.d.
it like some sort of conquering explorer,
FeS2 . . . . . . . . . 0.05 . . . . . n.d. . . . . . 0.09 . . . . n.d. . . . . . . n.d. peering with some trepidation down the
C . . . . . . . . . . . . 1.79 . . . . . 0.93 . . . . n.d. . . . . n.d. . . . . . . n.d. cliff-like bank of the river, on the brink
S03 . . . . . . . . . . 0.02 . . . . n.d. . . . . . n.d. . . . . n.d. . . . . . . n.d.
S . . . . . . . . . . . . n.d. . . . . . 11.0 . . . . . n.d. . . . 30.0 . . . . . . n.d.
of which I now perched. I had found the
MnO . . . . . . . . 58.0 . . . . . . tr. . . . . . . n.d. . . . . n.d. . . . . . . n.d. source of Peach Bottom slate! Or had I?
Where was the pit? All old slate quarries
[From: Slate in Pennsylvania, p. 375]
had huge holes in the ground, usually
filled with water, as well as huge piles of
82 The Slate Roof Bible — Chapter 7 — Peach Bottom Slate
 This manse, built in 1954 next to the Chestnut Level Presbyterian Church, was probably one of the last houses to get a new Peach Bottom
roof, although the slates may have been recycled. The nearby church, built in 1765, also has a Peach Bottom roof.
Photo by author.

scrap slate. There was no visible hole here, although getting hungry. As soon as we reached the quaint lit-
there had to be one somewhere nearby. I was reluc- tle town of Delta, we stopped at the diner on the
tant to explore further through these dense woods, main street. I ordered their lunch special, and while
however, as the ground was covered with one of the waiting for my soup I asked the waitress if she knew
thickest and most luxuriant growths of poison ivy I anything about the old Peach Bottom slate quarries.
had ever seen, and my kids were now left unattend- “I know just the person you should talk to,” she said.
ed a half mile away along a rural roadside. The swel- “Hold on a minute, let me see if he’s still here.” She
tering heat added to my desire to return to the van, disappeared into another room and soon returned
so I picked up a heavy chunk of slate and carried it with a wiry, elderly man named Harold Beucker,
back to the road where I found the kids patiently who pulled up a chair and began to fill me in on
waiting. “Let’s stop at that farm we passed and see if what he knew.
we can photograph their slate roofs.” “I was the last person to haul Peach Bottom
The middle-aged farmer, Allen Weikel, at slate out of here,” he said. “That was in 1956 or 57.”
that time a write-in candidate for Governor of PA, “Roof slate?”
explained that much of the slate was actually quar- “Yes, and I hauled it into the Pittsburgh
ried on the other side of the river. He was a very area. Fox Chapel, if I remember right. Best slate ever
friendly fellow who took a good hour out of his busy produced. Best slate in the world.”
day to make phone calls trying to locate someone “Why did they stop quarrying it?”
who knew about the history of the quarries. Soon we “Not economical. Too much waste, too hard
hit paydirt. We had Roger Faill of the PA Dept. of to work, to split. Some of it went underwater when
Environmental Resources Geologic Mapping the river was dammed. After they quit making roof
Division on the phone, and his advice was accurate slate they continued to make slate granules for a few
and to the point: “The museum in Delta. That’s years. They used the granules for roofing, like what
where you should go. I’ve never been there, but I you see on shingle roofs.”
hear that they have some good information on Peach “Where can I find out more about the histo-
Bottom’s history.” So off we went to Delta, PA, right ry of the quarries?”
on the Maryland border on the west side of the “The person you want to talk to is Ruth Ann
Susquehanna, the heart of the Peach Bottom slate Robinson. She lives just down the street. First house
region. past the Welsh church. The red brick one. She’s
By this time it was afternoon and we were all curator of the town museum. Museum’s only open

The Slate Roof Bible — Chapter 7 — Peach Bottom Slate 83

on weekends though. You won’t be able to see it ten miles, running northeast to southwest in three
today.” parallel belts 75 to 120 feet thick, and crossing both
After we finished eating, the kids and I set the Susquehanna River and the PA/MD border near
out for the Robinson house. No wonder I couldn’t where the Susquehanna flows out of Pennsylvania.
find an old quarry pit by the river, I mused as we The slate deposit, locally known as a slate “ridge,”
walked, it was probably under water! The first thing extends from York County, PA, about 3 miles into
I noticed when we reached the Robinson house, Cardiff Township, Harford County, MD. Its total
besides the Peach Bottom slate roofs on the church depth is estimated at 1000 feet, and its width is said
and the house, was a Welsh flag bumper sticker on to be one-fifth to one-half mile, although it seldom
the car parked in her driveway. Turns out that Ruth exceeds 200 feet in a quarry. About one and a half
and her husband Don had both visited the slate miles of the slate lay underneath the river until the
areas of Wales. Don was making wooden slate-split- construction of the Conowingo Dam submerged
ting hammers, like the ones used in Wales, in the more of it. The quarries were located near Delta, PA,
workshop behind his house. Once again, a kind and Peach Bottom, PA, and Cardiff, MD.
friendly person, Ruth Ann took time out of her busy Slate splitters had some problems getting
day to accommodate total strangers with absolutely Peach Bottom slate to split to their satisfaction, and
no advance notice. She opened up the Old Line eighty-eight percent of the slate mined in the Peach
Museum and dug around for material to show us, Bottom district became waste.
and some of the historical Peach Bottom slate
information about Peach was exhibited in the
Bottom slate in this book is Crystal Palace Exposition
attributable to her. in England in 1850 by
One important fact quarryman Roland Perry
that became clear to me dur- and was deemed the best
ing my investigation was roofing slate then known.
this: Peach Bottom slate is It is perhaps this award
from Pennsylvania and more than any other that
Maryland. The slate deposit gained Peach Bottom slate
straddles the state line and its fame. Ironically, and
it is a resource shared by the despite its durability,
two states. In fact, the slate Peach Bottom slate is no
was mined in Maryland longer quarried. It’s just
longer than it was mined in too hard to produce fin-
Pennsylvania. It was all ished slate products with
shipped out of Delta, PA, this material at a price the
though, and therefore market will bear. Perhaps
became known as a this will change in the
Pennsylvania slate. So now future and people will once
I’m trying to set the record again value durability over
straight. Peach Bottom slate convenience and renew the
is a Pennsylvania and markets for such fine slate
Maryland slate. products. Time will tell.
Marylanders are rightfully But don’t hold your
proud of their slate, but breath waiting. One recent
haven’t been given credit summer a beautiful and
where credit is due. In fact, rare Peach Bottom roof on
I had to go to Maryland to an old historic inn in a
photograph the highway small local town near me
sign, paid for by Maryland was damaged by a wind-
tax dollars, shown at the storm. I heard through the
beginning of this chapter. grapevine that contractors
The Peach Bottom had been hired to tear the
slate deposit extends about roof off and replace it with
84 The Slate Roof Bible — Chapter 7 — Peach Bottom Slate
fiberglass shingles. I knew this would cost the inn pening every day in the United States, it is not legal
owner many times the amount it would cost just to in Europe to tear off a perfectly good, traditional
repair the roof, so I contacted the inn manager and stone roof and staple a tar paper product on instead.
informed her that the inn would be losing one of the It is considered a breach of community standards
best roofs in the world. She passed the word on to and therefore prohibited. The entire community has
the owner, and it turned out that he didn’t care, a stake in the appearance of its buildings, and
because his insurance was paying for the replace- although this may be considered an unacceptable
ment roof. I then contacted the roofing contractor intrusion on personal liberties here in the USA, in
and offered to remove the slate, free of charge, so I Europe many quaint towns and villages continue to
could salvage them. I explained that these slates display the elegant charm they have demonstrated
would still last hundreds of years, that they’re no for centuries. Why? Because their building codes
longer quarried, they’re rare, and he would save a lot display a higher set of community standards which
of work if someone removed the slate for him, etc. I take into account such things as tradition and aes-
told him that if he didn’t like the idea of me working thetics. I fear that by the time we in the United
on his roof job, then he could take the slate off him- States have evolved to that level of standards, there
self and I would buy them from him. At the very will be few, if any, traditional slate roofs left.
least, I said, I could be there when the slate was Peach Bottom slate was more expensive than
ripped off and gather them up before they went into the other slates available at the turn of the century
a dump truck to be hauled to a landfill. The contrac- (1800-1900), so it had a tendency to be used on more
tor said he’d get back to me. A couple of weeks later expensive buildings and homes. It is certainly found
I drove by the inn to see the last of the Peach Bottom on common buildings near the quarry district, but far-
slate being smashed into a dumpster, while the last ther away it was sought after by people who had the
section of roof was having fiberglass shingles stapled extra money to spend for the very best material
to it. When I stopped and gave the contractor a piece available. Therefore, many ornate homes, churches
of my mind, he didn’t seem to understand what I was and government buildings had Peach Bottom slate
saying. Perhaps I was speaking the wrong language, on them, and today if you have an older, fancy home
but then I don’t speak Neanderthal all that well. or building with a hard, black slate on it, it may be
I’m mentioning this incident as a warning to Peach Bottom, unless the home is located near the
homeowners. Contractors may not care about your roof! Monson, Maine, or Buckingham, Virginia, slate dis-
Believe me, there are many contractors out there tricts (as these slates are also black and hard). For
waiting like vultures to tear off your good slate roof, example, some buildings that had Peach Bottom
destroy the slate, and staple glorified tar paper on slate on them by 1898 were the Pennsylvania State
instead. They care about the money they’re going to Capitol (roofed in 1820), Carnegie Library, Johns
make, not about tradition, craftsmanship, durabili- Hopkins University and Hospital buildings, Notre
ty, history and other things of character. Once your Dame Academy, the Biltmore Estate of George
permanent roof is torn off and destroyed and you Vanderbilt, and the residence of William B. Astor on
have it replaced with an inferior roofing product Fifth Avenue in New York City.
guaranteed to fail in 20 years or so, you are locked
into a cycle of roof replacement that will continue to HISTORY
put money into the pockets of the contractors forev-
er. Peach Bottom slate was first discovered in
Furthermore, when insurance is paying for 1734 by Welsh brothers who had settled in the area
something, many contractors will push the home- a few years prior. They used the slate to cover a roof,
owner to go for the most expensive option, no matter and the slates reportedly remained intact for 200
how wasteful. In other words, if you don’t protect your years until 1932 when the building burned. The roof
own slate roof, no one else will do it for you! In this case was still in perfect condition. One history book tells
I could say that the home owner deserved to lose the the story like this:
roof. But I saw this roof as an historic part of the
community, and the building as one that may last for “Two brothers, William and
generations and have many future owners. It is dis- James Reese, natives of Wales, took up
appointing when the owner of an historic building is land in 1725 under patent of the English
not considerate of the community and not concerned provincial Government, in what is now
about wasting good resources. Although this is hap- known as York County, PA, and during
The Slate Roof Bible — Chapter 7 — Peach Bottom Slate 85
A COMPARISON OF PEACH BOTTOM SLATE TO OTHER TYPES
OF ROOFING, CIRCA 1898, IN THE VICINITIES OF
PHILADELPHIA OR NEW YORK
MATERIAL COST LIFE COST/YEAR

Peach Bottom Slate . .$7.50 . . . . . .150 years . . . .5 cents

Tin . . . . . . . . . . . . . . .$5.50 . . . . . .20 years . . . . .27.5 cents
Shingles . . . . . . . . . . .$4.30 . . . . . .12 “ . . . . . . .35.3 “
Corrugated Iron . . . . .$5.10 . . . . . .10 “ . . . . . . .57.2 “
Tin Shingles . . . . . . . .$6.70 . . . . . .10 “ . . . . . . .67.2 “
Copper . . . . . . . . . . . .$30.00 . . . . .40 “ . . . . . . .75.0 “

“It will be readily seen that a Peach Bottom Slate roof is not alone
the most durable, but when the original cost and average life are
taken into consideration, it is five times cheaper than tin, seven
times cheaper than shingles, eleven times cheaper than iron,
and fifteen times cheaper than copper. Nor do these estimates
take into account the expense of maintaining metal and wooden
roofs. Tin and iron require frequent paint to prevent rust. Shingles
require paint to prevent rot. Copper requires frequent soldering
at the joints to keep the roof from leaking. A slate roof, when
properly put on, is practically permanent and requires compara-
tively no repairs.” [Times Herald, Delta, PA, November 18,
1898]

The above advertisement is from a publication dated December,

1898: “The History and Characteristics of the Peach Bottom
Roofing Slate.”

The octagonal roof (top, right) is being hoisted by crane onto the
Caparosa house in Butler, PA. The main house already has an
historic Peach Bottom slate roof (closeup, right). The tower will be
slated with Buckingham slate from Arvonia, Virginia, which today
most closely matches Peach Bottom slate both in appearance
and durability. See photo of slated tower on page 91.
Photo at top by Kevin Caparosa, other photo by author.

86 The Slate Roof Bible — Chapter 7 — Peach Bottom Slate

 the year 1734, when excavating for thirty Peach Bottom quarries or prospects were list-
foundations for farm buildings, they dis- ed west of the Susquehanna River and twelve east of
covered the slate rock from which they the river, including the remains of one I “discov-
split the pieces necessary for roofing their ered” with my kids. By 1929, only three Peach
buildings. This was the first use of slate Bottom roofing slate operations existed in
in America.” [From Peach Bottom Maryland, and none in Pennsylvania, and a year
Roofing Slate, 1898, p.5] later only two remained in Maryland. In 1997, there
were no slate quarries producing Peach Bottom roof-
Those same pieces of slate were still in use in ing slate.
1898 when the above historical account was pub- To illustrate the strength of Peach Bottom
lished, on their seventh building, apparently having slate, a compression test was conducted in 1893,
outlasted six others. “They show no disintegration or indicating that the slate would crush at 385.6 tons
decay [after 163 years] and still retain the strong, bril- per square foot of pressure applied parallel to natu-
liant, blue-black color for which this slate has become ral cleavage, and 758.4 tons per square foot applied
famous by the name of Peach Bottom.” That seventh perpendicular to natural cleavage. Another set of
building was reported to be a hog pen located near tests (1892-94) showed an average crushing strength
Delta, PA, and still standing in 1930. It is reported of 11,260 pounds per square inch, a figure typical of
in The Stone Industries (1934) that a sample of this a good quality slate.
slate was “rescued from this lowly use and is now on Because Peach Bottom slate had gained fame
exhibit at the United States Bureau of Mines in due to its award at the Crystal Palace Exposition in
Washington, D.C. After nearly 200 years of service, it England in 1850, other quarries began to falsely
shows no evidence of deterioration.” Take a look at the refer to their slate as Peach Bottom as well. These
photo of the one-inch-thick, 250-year-old gravestone imitations went by the names of Slatington Peach
illustrated on page 14 for an example of the durabil- Bottom, Lehigh Valley Peach Bottom, and Peach
ity of this slate. Bottom of Lehigh Valley, and were decried by pro-
One of the first slate roofs made of Peach ducers of “genuine” Peach Bottom slate as “cheap
Bottom slate was laid by Joseph Hewes, a signer of imitations named to deceive the public,” which they
the Declaration of Independence. The first commer- probably were.
cial quarrying began around 1785 by a fellow named Today’s lack of existing Peach Bottom quar-
William Docker, but quarrying didn’t get into full ries dictates the need to carefully salvage and
swing until the Welsh stepped into the scene in large reclaim Peach Bottom slates from buildings that are
numbers around 1845. In 1848, about 30 Welsh peo- scheduled for demolition, or even scheduled for re-
ple arrived in Philadelphia en route to Peach Bottom roofing. However, there is still one type of slate quar-
to become slate quarriers, splitters, blacksmiths and ried in the USA today that somewhat resembles
stone carvers. The Welsh introduced quarrying Peach Bottom both in appearance and durability,
methods brought over from the quarries in and which can be used with satisfactory success as a
Gwynedd, North Wales (see Chapter Four). Peach Bottom substitute. This is the “Buckingham”
By 1858, 18 quarries were reported in opera- slate of Virginia, which we discuss in the next chap-
tion west of the river and 11 east of it. At one time, ter.

Old payment receipt for Peach Bottom slate.

1901 Advertisement

The Slate Roof Bible — Chapter 7 — Peach Bottom Slate 87

 Chapter Eight

VIRGINIA AND GEORGIA

V
irginia slate (Arvonia-Buckingham itself is known
slate belt) is black, very hard and geologically as
durable, and is guaranteed by one “Arvonia” slate on
manufacturer to last 150 years on a roof. It has a state maps. The
characteristic glistening sheen indicative of a high slate lies in three
level of quartz, which sparkles in the sunlight when distinct veins, the
the slate is new. This slate is still quarried today in first having such a
the little town of Arvonia, Virginia, deep in the rich fine grain that it
heartland of the state. can hardly be
This “lustrous” slate is said to be “blue- detected, the next
black,” “deep black” or “oxford gray;” however, for having a coarser
our purposes “black” is close enough. It is said to grain, and the
have the lowest average absorption (less than .02 per third vein
cent) of any American slate when submerged in remains undevel-
water, which is a very good indication of longevity. It oped.
is also claimed to have equal strength both with and The slate
across the grain, which is unusual for slate. A man- has an overbur-
ufacturer also states that this slate shows the least den of shale sit-
deterioration of any other slate in corrosive tests. ting on top of the
Add to this the fact that the slate does not change working slate bed
color with age, and you have, all in all, one of the that is 40 to 60
best slates on the market today, rivaling Peach feet thick. This
Bottom slate (which is not on the market), Monson overburden con-
slate (also not on the market, although the Glendyne stitutes the only
Quarry in Quebec now offers a substitute), and the waste derived
best green, purple and red slates of Vermont/New today from that
York. In other words, this slate should last the life of quarry’s open-pit
the building it is attached to. And if the building operations as the Virginia’s slate quarries are in
wears out before the slate does, the slate can be slate refuse is Buckingham County near Arvonia, in
removed and used on another building. In some crushed for road the center of the state.
cases, as is done in some parts of Europe, the slate aggregate.
may be removed from an old building, the old roof Although many roof slates from this area are
boards removed and replaced, then the same slate made from single beds, others show ribbons (“rib-
renailed to the new roof boards on the same building bing”) indicating they were cleaved through a suc-
with new nails. In this way a good slate roof can be cession of beds, giving the slate an attractive striat-
preserved indefinitely. ed appearance, but not affecting durability in this
The slate bed at Arvonia is 600 to 800 feet type of slate. Some thin beds only a few inches thick
thick, 10 to 15 miles long, and 1 to 1 1/2 miles wide. contain fossils of crinoids, brachiopods and trilo-
It extends across parts of Buckingham and Fluvanna bites considered to be of Ordovician age (500 million
counties, and crosses the James River near the town years old). Other fossils including clams have been
of Bremo Bluff. Although often referred to as found. The deepest quarry in the district was report-
“Buckingham” slate in today’s slate industry, that ed to be over 350 feet deep and depths of over 200
term is a trademarked product name, and the slate feet are not uncommon. One of the largest single
Opposite: Many government buildings in Washington D.C. are covered with Buckingham, Virginia, slate roofs,
such as the Smithsonian Institution Building, known as the “Castle.”
Photo by author.

The Slate Roof Bible — Chapter 8 — Virginia and Georgia 89

 slabs of slate from the Arvonia-Buckingham slate
belt trimmed to seven and a half feet by eleven and
a half feet in width and length, and was able to be
split to only one and a half inches in thickness!
Slate deposits are also found in the Esmont
area in Albemarle County, in the Warrenton area of
Fauquier and Culpeper Counties, and in the
Quantico slate belt in Stafford and Spotsylvania
Counties, all of which are inactive.
Here again, as we have seen throughout the
other major slate producing regions of the United
States, Welsh people essentially started the slate
quarries. The name “Arvonia” for example, comes
from “Arvon” which is a derivative of “Caernarvon,”
the name of the county (and city) in North Wales
from which many a slate worker emigrated. A
“caern” is a “fort” in Welsh, and the name
Caernarvon was shortened to just Arvon when the
Welsh settled in Virginia, eventually to again be
altered to its final form, Arvonia. A principal town in
Caernarvon, Wales, is Bangor, and that name was
given both to Bangor, Maine, and Bangor,
Pennsylvania, by Welsh immigrants.
Early reports of the use of slate in Virginia
are sketchy, and by all accounts the first slate roofs
s David Crummette, of Buckingham Virginia Slate Corporation came to Virginia from England. In 1662, the Virginia
(1995), Arvonia, Virginia, demonstrates the use of a modern electri-
cally powered slate trimming machine with a “guillotine” style blade. General Assembly authorized the building of 32
Untrimmed pieces sit to his left, foreground. The trimmed houses at “James City” and specified slate roofs for
Buckingham “blue-black” slate is shown below and on page 92. these buildings. At that time, however, slate was not
Photos by author.
being procured from Virginia’s own deposits.
Likewise, in 1706, slate was again specified for the
roof of the Governor’s house in Williamsburg,
authorizing its purchase from England. During the
mid 1700s, the Virginia Gazette published notices of
shipments of slate from Germany, Ireland and
Algiers.
By 1755, slate roofs were being described in
print, along with lead, shingle and tile roofs, on
Virginia houses, and although Virginia’s slate
deposits were known then and were probably
worked to some extent, it is not clear what percent-
age, if any, of these roofs were made of Virginia slate.
In 1794, a contract was awarded to a roofing firm for
the purpose of slating the roof of Virginia’s Capitol
with slate from a Buckingham quarry, stipulating
that the job had to be completed by 1796. Again, for
reasons that are not clear today, that contract was
never honored, and the Capitol was instead roofed
with wooden shingles.
It is known that at least one quarry was in
operation in Buckingham County by 1812.
Unfortunately, just about that time, Thomas
Jefferson, noted for (among other things) his archi-
90 The Slate Roof Bible — Chapter 8 — Virginia and Georgia
tectural genius, decided that “slate is a bad covering
because [of its] constantly getting out of repair.” He
preferred roofs covered with tin instead, approving
of a roof design that only rose vertically a half inch
in each foot of horizontal run, which is practically
flat by today’s standards. So, for a while, major roof
contracts were given to tin roofers rather than slate
roofers, and Jefferson advised “to cover with tin
instead of shingles. It is the lightest and most durable
cover in the world. We know that it will last 100 years,
and how much more we do not know.”
Well, Jefferson’s advice was clearly off target
and, unfortunately, disastrous. The tin roofs lasted
only ten years, and when they were replaced, the
owners specified slate, one person noting in his
diary that he had “commenced taking off roof of the
house to be replaced by a new one to get rid of the evils of
flat roofing and spouts and gutters, or in other words to
supercede the Jeffersonian by the common sense plan.”
By 1835, the tide was turning for Virginia
slate. Geologist W. B. Rogers reported to the Virginia
legislature that “in texture, density, and capacity of
resisting atmospheric agents [Buckingham County slate] s Preservation expert Bryan Blundell squirms through a trap door in
can scarcely be excelled by a similar material in any part the Smithsonian Institution Building known as the Castle, surrounded
of the world.” by Buckingham County, Virginia, roofing slate.
By 1851, the slate was receiving “honorable
mention” at the London World’s Fair in England,
followed in 1876 by a gold medal at the Philadelphia
Exposition, and yet another medal in 1893 at the
World’s Columbian Exposition.
Perhaps the greatest factor involved in get-
ting Virginia’s slate industry moving was the Welsh
influence. In 1867, as Virginia still smoldered from
the Civil War, immigrants from North Wales began
to move into central Virginia in search of opportuni-
ty in the slate quarries. Some of the Welsh people
came down from Vermont where they had settled for
the same purposes. By 1881, one Virginia Welsh
quarry employed 100 mostly Welsh workers, when a
week’s shipment of roofing slate may have equaled a
hundred tons in weight and traveled as far as San
Francisco by rail. The advent of the railroad into the
Virginia slate district in 1885 opened the final door
to the markets, and the slate industry flourished,
booming between 1900 and 1910, approximately the
same time slate production peaked in Pennsylvania.
Once again, World War One had a bad
impact on the slate industry, and of eight Virginia
slate quarrying companies existing before the war,
only four continued afterward. By 1928, there were
s “Buckingham” slates from Buckingham County, Virginia, sold by
only three companies in operation, but with the Buckingham Slate Company, are often referred to as “blue-black”
introduction of earth-moving equipment, produc- slates. Here they are being installed on an octagonal tower by Barry
Smith at the Caparosa residence in Butler, Pennsylvania (above).
tion actually rose to new highs. Still, the Great Photos by author.

The Slate Roof Bible — Chapter 8 — Virginia and Georgia 91

 Depression caused quarry operations to virtually
cease in the early 1930s, when, in 1932, slate produc-
tion was as low as it had been in 50 years. By 1940,
the three companies had recovered sufficiently to
employ about 420 workers, but then along came
World War Two, grinding operations to a halt, after
which operations resumed at one third the pre-war
level.
By 1962, however, 100,000 tons of finished
slate products were being shipped from
Buckingham County, Virginia, to all parts of the
United States.
Today, the immense deposits of slate in
Virginia have hardly been touched. Sources of
Virginia’s high quality slate are listed in the back of
this book.

GEORGIA

The state of Georgia was never a big produc-

er of roofing slate, nor could it begin to compare to
Virginia in either quantity or quality of slate pro-
s Worker at Buckingham-Virginia Slate Corporation in Arvonia,
Virginia, trimming the famous “Buckingham” slates. duced. Yet, slate mines did flourish for a while in
this southernmost slate producing state. Deposits
Photo courtesy of Buckingham Virginia Slate Corp.
suitable for roofing are found in the northwestern
corner of the state near the Cohutta, Silicoa, Pine
Log and Dug Down Mountains in the southern
Appalachian range. The quarries were localized in
two areas: at Rockmart in Polk County, and at
Fairmount in Bartow County. Both quarry areas ini-
tially produced roofing slate, although both subse-
quently manufactured only crushed slate products
(aggregate), until eventually all production died off
in the 1970s (Fairmount) and 1980s (Rockmart).
Slate deposits have also been reported in Murray,
Gordon and Fannin Counties. Lindsay (1974),
reports that the principal slate producing states in
America in 1897 included Georgia, and Lindsay’s
History of the North Wales Slate Industry strongly
implies that Georgian slate was exported to Europe
at that time.

ROCKMART

Georgia’s two quarry regions produce dis-

tinctly different types of slate. The Rockmart slate,
debatably of Paleozoic age (between 230 million and
600 million years old), is known as black, or “blue-
black” (actually gray), and is very similar to the slate
of eastern Pennsylvania’s Lehigh-Northampton
“hard vein” district. Some Rockmart slate remains
quite hard and durable a century later, and appears
similar to Peach Bottom slate, while other varieties
92 The Slate Roof Bible — Chapter 8 — Virginia and Georgia
 s The Rockmart Presbyterian Church, built of slate, displays the gray Rockmart slate on the bell tower.

(Above right) Gravestone at the old Methodist Church cemetery in Van Wert, marking the grave of a soldier who died in
1861. The slate is still in very good condition, although many of the old slate gravestones in this cemetery have eroded
beyond recognition, demonstrating that Rockmart slate is both hard and soft, depending on the quarry site.

t Typical Rockmart slate roof.

Photos by author.

The Slate Roof Bible — Chapter 8 — Virginia and Georgia 93

 s An example of Rockmart’s harder slate, still in good condition despite its age.
Photo by author.

seem to be softer, becoming rather soft after a centu- 8, 1799, in Savannah, Georgia, of French parents,
ry. Apparently, the different grades of Rockmart and moved to the Rockmart area in 1847. One story
slate depended on their original location within the describes him stumbling over an outcropping of
actual quarries, the harder slate coming from one pit slate as he was tying up his family cow, thereby mak-
or mine, and the softer from another. ing his memorable discovery. Another version
Much of the slate quarried has been ground describes Mr. Blance’s discovery as a byproduct of a
up for aggregate and used as a concrete filler, asphalt road-grading project he was doing at the time
shingle coating, etc., due to the lack of a smooth-tex- (maybe the cow was pulling the grader). In any case,
tured, finely grained slate suitable for splitting into he subsequently established the Blanceville Slate
shingles. As a result, there is not an abundance of Mines and invited the Welsh to step in and lend a
Georgia slate roofs in the Rockmart area at the time hand. No doubt the Welsh were lured by stories of
of this writing, and many of those that still exist tend “the largest, most inexhaustible deposit of slate south of
to be, unfortunately, in poor repair. Pennsylvania” reportedly discovered near the village
According to the Geological Survey of of Van Wert (an extension of Rockmart). One
Georgia (Bulletin 27, 1912), Rockmart slate is a notable Welshman was Colonel Seaborn Jones, cred-
“very bluish-gray color and of slightly rough and ited as one of the originators of the Rockmart slate
lusterless surface.” The survey adds, “This is a mica industry. Colonel Jones established extensive land
slate of the fading series [will change color some- holdings and became a major benefactor of the city
what with exposure to the weather], although some of Rockmart.
obtained from a tunnel at one of the quarries is The average value of farmland in Polk
reported to have kept its color for many years. Its fis- County in 1850, when slate was being discovered,
sibility [ability to split] is fair.” was about $10 an acre, and most people earned their
Once again, the development of the slate living growing cotton, corn, peaches and other
industry in the Rockmart fruits, or operating dairy
area was attributed to the farms. Some worked in
Welsh (pronounced cotton mills. That all
“Welch” by the locals, changed as the slate
with a hard “ch”), industry expanded and
although the first quarry became a major employer
was opened around 1850 of men in the area.
by a Mr. Blance, who dis- Although the Civil
covered slate on his own War interrupted the
plantation in 1849. Mr. development of
Blance was born on May Rockmart’s slate industry

94 The Slate Roof Bible — Chapter 8 — Virginia and Georgia

as the men took up arms and engaged in battle, in although one older farmer did remember a hotel on
1863 some mining was done to provide roofing for Slate Mine Road that had Fairmount slate on the
military purposes. The quarries nevertheless roof, but which had burned to the ground. It
remained at a standstill for fifteen years after the appeared that, although Fairmount slate was once
war, reopening around 1880. They then produced quarried for roofing, it was only done in small quan-
their greatest yield during the following decade, tities and the roofs were eventually lost to neglect or
with 5,000 squares of roofing slate (enough to cover ruin. There are some roofs in Atlanta, and presum-
420 houses) valued at $22,500, being produced in ably in other areas of Georgia, with green slate roofs
1894. According to the U. S. Geological Survey, which may have originated in Fairmount, but the
Georgia produced 38,097 squares of roofing slate origin of the roofs is pure speculation due to the sim-
from 1879 until the beginning of World War I, val- ilarity in appearance to green and sea green roofs of
ued at $165,918, although these figures are thought Vermont.
to be incomplete. It is reported that the total roof The green slate belt was first prospected by
slate production of the Rockmart district was over Mr. G. W. Davis, a slate worker from Pennsylvania
50,000 squares, enough to cover about 4,200 average employed in the Rockmart district. The exact date is
size homes. uncertain. The belt extends through Gordon, Bartow
Roofing slate production dropped off after and Murray Counties. Huge water-filled pits remain
1900 and was replaced by the quarrying of slate to hidden among the forested hills about four miles
make light-weight aggregate. The aggregate, known south of Fairmount, bearing evidence of the old slate
as “Galite” (a contraction of Georgia lite), was made industry. From these pits emanate large tunnels for
by heating crushed slate to 2,000 degrees F., which a total distance underground of 12 miles, according
causes it to expand. The resulting “expanded shale to quarry owner Ray Sullivan (see photos, page 96).
aggregate” was added to concrete to reduce the con-
crete’s weight, but not its strength, and is incorpo-
rated into such structures as the Golden Gate Bridge
and the White House. The Rockmart Slate
Corporation quarry in Rockmart, Georgia, was plan-
ning to renew the production of ground slate in 1997
to be used as a horticultural mulch material called
“Slatescape.”
FAIRMOUNT

The slate near Fairmount, thought to be

Cambrian in age (600 million years old), is green,
similar to the sea green slate of Vermont, but with
more color variety, showing shades of blue, buff,
brown and red.
Fairmount slate at quarry sites appeared to
the author to be quite hard, although not a single
Fairmount slate roof could be found by the author
and a colleague, who spent a couple of days in 1997
searching in vain for slate roofs in the Fairmount
area. It is reported in historical accounts that these
slates did not “possess the hardness of the best
Rockmart slates,” and due to the lack of existing
roofs, the author had no way to visibly and with cer-
tainty determine the longevity of Fairmount slate
roofs.
There weren’t many local folks who remem-
bered the operating slate quarries either, and those s Slate Mine Road near Fairmount, GA, is reportedly a site of old
that did only remembered the slate being ground Georgia slate mines, but only traces now remain there. The huge
into aggregate. No one was old enough at the time to quarry holes pictured on the next page are several miles away, on the
other side of town.
remember slate ever being quarried for roofing, Photo by author.

The Slate Roof Bible — Chapter 8 — Virginia and Georgia 95

 s Abandoned slate quarry pit near Fairmount, GA. Note person standing near top, just right of center (circled).
t These huge tunnels extend 12 miles underground, now accessible only by boat.
Photos by author.

96 The Slate Roof Bible — Chapter 8 — Virginia and Georgia

 Chapter Nine

MAINE AND CANADA

T
he slate from the Monson region of berg when he saw
Maine is black, smooth and will last that first slate out-
for centuries on a roof. The people of cropping, for it was
that area will say what is commonly heard in all slate only a tiny section of
regions in the US, that their slate is “the best slate in one of Monson’s two
the world.” Unfortunately, at the time of this writ- immense slate belts.
ing, Monson slate is no longer being quarried for The village belt was
roofing. Quarries stopped producing roofing slate in 200 feet in width,
Monson for the same reason they stopped elsewhere and became one of
throughout the world: increased cost, market fluctu- two belts known as
ations and decreased demand. the Monson-Maine
Older Monson slate roofs are, nevertheless, Co. vein and the
excellent roofs very much worthy of restoration Po r t l a n d - M o n s o n
efforts. People who put their money or efforts into Co. vein, both of
restoring their Monson roofs will benefit greatly in which ran east to
the long run, both financially, by keeping a perma- west.
nent roof over their heads, and aesthetically, by pre- Soon after
serving a traditional, natural and beautiful stone Jones’ discovery,
roof. slate quarries sprung
The restoration of Monson roofs requires up all over the area.
ample supplies of replacement slates, and since the The first quarry
slates are no longer being manufactured, old roofs after Jones’ was
that are being removed (as on buildings to be demol- called the Hebron
ished) should be carefully salvaged and stored until Pond Quarry, started
needed. This careful recycling of Monson slate will by a Mr. Chapin. It
ensure that many of the old roofs will be kept intact, suffered an unfortu-
as one of the most necessary ingredients in slate roof nate accident in
restoration is replacement slates that match the slate 1881, when two men
on the roof. Recycling of roof slate is discussed in were injured and a
greater detail in Chapter 16. third man killed. In
Monson is a quiet, quaint little village, 1872, a Mr. Norris opened a quarry and installed
founded in 1822, just two years after Maine gained steam power, a new-fangled addition to the Monson
statehood. Nestled on the shore of Lake Hebron, area quarries at that time, but he didn’t have much
near Monson Pond, it is just a few miles south of the luck with it — his buildings burned to the ground
beautiful Moosehead Lake in north central Maine. five years later.
Life changed for the residents of Monson in In the meantime, many people of English,
the summer of 1870, when William Griffith Jones, a Irish and Scottish descent immigrated to the
Welshman, discovered an outcropping of slate while Monson area from New Brunswick and Nova Scotia
riding his horse. Welshmen at that time were consid- to develop and work the quarries. William Thomas,
ered the foremost authorities on excavating and cut- Commissioner of Immigration, brought Swedes to
ting granite, marble and slate, and apparently Mr. the area in 1870, and later Finnish people arrived to
Jones understood that slate had commercial value, help work the slate mines.
so he bought the slate-bearing land from a hotel In 1873, Fred Jackson founded the Cove
keeper and started the development of his Eureka Quarry, which utilized some of Mr. Norris’ machin-
slate quarry within days. ery, thereby sparing its loss in the later fire. The
Mr. Jones discovered only the tip of an ice- same year, Dexter and Portland Companies founded
The Slate Roof Bible — Chapter 9 — Maine and Canada 97
 s Monson, Maine, slate roofs with the characteristic smooth sheen of the legendary Monson slate. Photos by author.

Arthur Day recorded the layout of the mine where he worked by a crude sketch on a piece of paper, from memory,
before he died. The only notes associated with his mine diagram stated, “The west end tunnels do not connect with the
east end tunnels. There is no heavy flow of water in any of these tunnels and shafts, just a few trickling springs. This
is the reason they never found any of the dye they put in the dump. The water in the pits neutralizes trickling spring
water so no flowage occurs.”

98 The Slate Roof Bible — Chapter 9 — Maine and Canada

the Dirigo Quarry, followed by the Forest Quarry early 1990s. Sheldon Slate Products of Monson,
(opened by people named Forest) in 1874. Then the Maine, the only slate quarry in operation in that
Underground Quarry, operated by John Folsom, area today, produces countertops, floor tiles, flag-
sprung up in 1875; then John Tripp’s Oakland stones etc., but not roofing slate.
Quarry in 1877; the Monson-Maine Quarry in 1880 On the opposite page is a map of the
(by Allen Williams); the Kineo Quarry and the Monson-Maine Co. mine shafts and tunnels as
Burmah Quarry in 1882; the West Monson Quarry recorded by Arthur Day, a quarryman who drew the
(W. M. Jones) in 1895 (the buildings burned January map for posterity in the 1980s at about age 80. He
16, 1897); the Matthews Quarry in 1902; the indicates that some of the tunnels descended to 900
Portland-Monson Quarry in 1906; the Farm Quarry feet, and that an electric locomotive eventually came
and the Wilkins Quarry in 1910; and the Eighteen into use in the tunnels, presumably to move the slate
Quarry in 1919 (abandoned in 1922). along tracks laid on the tunnel floor. He also shows
Some of these smaller quarries were eventu- where a side tunnel was carved from the main tun-
ally bought up by the larger ones, and by 1882, 12 nel to allow men a safe place to duck, complete with
years after Mr. Jones discovered the first slate out- benches to sit on, when blasting took place in the
cropping, $150,000 had been invested in the opera- main tunnel. Other quarrymen of the area tell of
tion of five quarries in the Monson area. Six hun- mine tunnels 1,100 feet deep, and of a shaft under
dred and twenty railcar loads of roofing slate, equiv- Monson Pond, two of which are evident in Mr. Day’s
alent to 2,500,000 square feet of roofing, were being diagram.
manufactured annually, requiring 200 men and 35 In addition to the quarries in the Monson
horses, as well as twelve teamsters to haul the slate area, the neighboring town of Brownsville, twenty
to the railroad. Two thousand five hundred cords of miles to the east, had quarries that produced much
wood were used each year, and about $6,000 was of the famous roof slate known as Monson slate.
being generated annually in local wages by the quar- Also, a small town called Blanchard a few miles to
ries. By 1885, a newspaper was being published out the west of Monson quarried slate, as did Burnham,
of Bangor, Maine, called “The Monson Slate.” about 45 miles south of Monson.
By 1922, a scant forty years later, there were The quarry business was not without its dan-
only three quarries in operation — the Portland- gers, as we have seen in previous chapters, and
Monson, the Monson-Maine and the General Slate Monson was not immune to them. Numerous acci-
Co. The Monson-Maine Quarry outlived the dents took place over the years in addition to the loss
General Slate Co., but was eventually abandoned in of buildings to fire. Not only were workers killed or
1943. The Portland-Monson Slate Company was run injured in the mines, but people drowned in aban-
by the Coleman family until April 1, 1965, eventual- doned quarry pits that filled with water, and others
ly to change hands to the Tatko family, who renamed died after falling over the cliff-like sides of the open
the company the Sheldon Slate Products Co. in the slate pits.
Perhaps the most well-known use of Monson
slate was for the Kennedy Memorial stone marking

s A slate splitter at Trinity Slate in Newfoundland using a pneumatic splitter. (Right) The purple and green slates that are characteristic of
Newfoundland grace an older home. These slates have a reputation for being quite durable. Photo at left courtesy of Newfoundland Slate, Inc.; photo at right by author.

The Slate Roof Bible — Chapter 9 — Maine and Canada 99

 The Glendyne Slate Quarry in Quebec, Canada, produces the sought after “North Country Black” roofing slate.
Photos courtesy of Glendyne Slate Quarry.

CANADIAN
SLATE QUARRYING AREAS
One of the first known Canadian slate quarries opened
in Rimouski in 1728.

Glendyne Slate Quarry at St.-Marc-du-Lac-Long is

an internationally known source of high quality black
roofing slate, known by the trade name of “North
Country Slate” in the U.S.

The durable purple and green slates of Newfoundland

are quarried on the shores of Burgoyne’s Cove, off
Trinity Bay, on the remote east coast of Newfoundland.

The Kingsbury, Richmond, Danville and Melbourne

area of Quebec once quarried a black slate similar to
that of eastern Pennsylvania. A slate museum is now
located in Melbourne.

100 The Slate Roof Bible — Chapter 9 — Maine and Canada

President John F. Kennedy’s grave at Arlington 1992, and is dedicated to the preservation of slate
National Cemetery. Saint Patrick’s Cathedral in roofs in the Kingsbury-Melbourne-Richmond area
New York City also has a Monson slate roof. of Quebec.
Slate was discovered in the mid-1800s on the
(Much of the historical information about Monson’s quarries eastern seacoast of Canada in Newfoundland, the
comes from “The History of Monson, Maine - 1822 - 1972,” pub- slate being of Cambrian age, meaning it had been
lished by the town of Monson, Maine).
highly metamorphosed into a very hard and durable
stone, and is therefore categorized as S1 (hard) slate.
CANADA
This type of slate can be expected to last hundreds of
years on a roof, with proper maintenance. It is iden-
“Newfoundland possesses one of the great roofing slate
tical to the slate of Wales, particularly from the
deposits in the world.”
Professor G. B. Walcott, Director of the Smithsonian Institute Penrhyn, Dinorwic, and Dorothea Quarry areas,
(late 1800s) yielding shades of purple and green.
The first quarry in the Newfoundland region
One of the first known slate quarries to be was opened by the Welsh in the mid 1850s and most
opened in Canada was near Rimouski on the south of the slate quarried at that time was used locally or
bank of the St. Lawrence River. Opened in 1728, the shipped overseas. The quarry shut down in the early
slate was found to be of a poor quality and the quar- 1900s, as did many others throughout North
ry was abandoned in 1733. Another formerly pro- America, due to economic hardships and market
ductive Canadian slate district is located about 60 fluctuations. However, the Newfoundland quarry re-
miles north of Newport, Vermont, near Richmond opened in the mid-1980s, and in 1991 the ownership
and Danville, Quebec. Here, slate was first mined in changed and the operation expanded into a new,
1854 at the Steele Quarry (later called the Bedard large mill building with new equipment. Roofing
Quarry), about 3 kilometers southeast of Richmond. slate was subsequently produced there under the
The first profitable quarry opened in 1860, less than trademarked brand name “Trinity Slate,” using fully
2 kilometers northeast of the village of Kingsbury, automated equipment including diamond wire
and was known as the Melbourne Quarry (also machines in the quarry, laser guided saw systems for
called Walton Slate). A square of slate at that time cutting blocks, pneumatic hammers for splitting the
sold for $3.50 Canadian, while the quarry wage 30 individual roof slates, and pneumatic trimmers for
years later still only hovered around eighteen to trimming the slates to their final size.
twenty-three cents an hour. The slate from this In the late 1990s, Newfoundland claimed to
region was black and similar to the slates of eastern have the largest production of natural roofing slate
Pennsylvania. in North America with distribution in the UK,
In 1878, the Melbourne Quarry shut down, Europe, Japan, Australia, New Zealand, and North
and the New Rockland Quarry, which began in 1868, America. Newfoundland Slate, Inc. with its quarry
then became the only important slate quarry in the site at Burgoyne’s Cove, off Trinity Bay, laid claim to
region, monopolizing 80% of the Canadian roofing being “the only slate quarrier in North America with
slate market. The New Rockland Quarry employed the prestigious ISO 9002 Certification,” an interna-
150-300 workers in the late 1800s, many of whom tional standard for quality assurance. However, at
were Welsh and Cornish, and who were localized in the end of the 20th century, Newfoundland slate was
the village of New Rockland. The quarry continued no longer in production, and with the vagaries of
until 1924, after which the inhabitants of the village slate manufacturing such as they are, the reader may
moved away and now no buildings remain there. By have to do some independent homework to keep up
the time the New Rockland Quarry was in its wan- with the changes in the industry. The latest indica-
ing years, it produced no more than a third of the tion is that, in 2003, roofing slate was again available
slate consumed in Canada, while much was instead from the Newfoundland quarries.
imported from the United States. Roof slate is still being quarried at the
Today, one may visit Melbourne’s “Slate Glendyne Quarry at St-Marc du Lac Long in
Interpretation Center,” a slate-roofed museum at 5 Quebec, which is about a hundred miles north of
Belmont Street, Melbourne, Quebec, just across the Monson, Maine. This quarry began operation in
river from Richmond via an old steel bridge (10 1995 and yields a slate similar in appearance to
miles from Kingsbury, or about 60 miles north of the Monson slate.
Vermont border). The center was incorporated in
The Slate Roof Bible — Chapter 9 — Maine and Canada 101
 Chapter Ten

INTERNATIONAL SLATE
Germany, Italy, France, Spain, China, Scotland and the U.K.

Slate is also produced in

Norway (see Industry Resource

T
his is by no means meant to be an Guide in the back of this book).

exhaustive description of interna-

tional slate. There have been and still
are slate quarries in numerous countries not elabo-
rated upon here, such as South Africa, Australia,
Switzerland, India, Belgium, Brazil, the Czech
Republic, Norway and others. Consider this as only
an introduction to the slate of the world, and please
understand that any omissions and deficiencies in
the information presented herein are simply a
reflection of the author’s limited knowledge.

GERMANY

German slate roofing expertise is renowned

across Europe and around the world. German slat-
ing styles and skills have been perfected over hun-
dreds of years, if not thousands. Archeological evi- Schlema in the
SLATE IMPORTS TO THE U.S.
dence in Germany indicates that roofing slate has Erzgebirge in the September 1997
not only been used there since 300 BC, but a unique Saxony Ore (customs values in dollars; all slate products)

style of slating known as “Altdeutsche” (Old Mountains (See Italy . . . . . . .896,626

German) has been carried on since that ancient Chapter 14). These India . . . . . . .729,295
schools, funded by tax China . . . . . .526,890
time. Germany is the source of many fine slate roof-
dollars, teach the var- Brazil . . . . . .377,432
ing tools made by such well-known firms as the UK . . . . . . . .193,075
Freund Company and the Carl Kammerling (CK) ious old traditional Canada . . . .156,122
Company. The world’s second largest roofing slate slate roofing skills Spain . . . . . .130,000
distributor, Rathscheck, also resides in Germany, in and techniques as South Africa . .67,211
well as tile roofing, Portugal . . . . .12,764
the beautiful Mosel River Valley. Mexico . . . . . .11,576
Germany’s characteristic black roof slate is sheet metal work, Philippines . . . .7,149
still mined in Germany at four locations — the artificial slate and
Mayen area in the Mosel Valley of western Germany even low-slope roof-
SLATE EXPORTS FROM THE U.S.
(known as “Mosel Schieffer,” or Mosel Slate); the ing applications. It September 1997
Bad Fredeburg area in the pine-covered mountains seems that in (customs values in dollars; all slate products)

of north central Germany (known as Magog Slate); Germany, like in the Bahamas . . . . . .199,419
the rural hills south of the Mosel Valley in the United States, roofing Belize . . . . . . . . .170,172
is almost strictly a Canada . . . . . . .155,389
Bundenbach area; and Lehesten, where Japan . . . . . . . . . .80,065
Schmiedebach (Thuringia) slate is mined in an open man’s trade (to the
Venezuela . . . . . .55,351
quarry. relief of most women, Cayman Islands .44,317
Germany also has at least four roofing no doubt), as no Mexico . . . . . . . . .30,455
schools, one in the Bad Fredeburg area, one in the females were seen South Africa . . . . .25,939
studying at either of Ireland . . . . . . . . . .9,636
Mayen area, one in Lehesten (Thuringia) and one in Source: Stone World, January 1998;
these schools during originally from U.S. Dept. of
Commerce
Opposite page: Building at the Castle complex in Edinburgh, the author’s visits.
Scotland, built in 1630, with graduated Scottish slate roof. The schools were
Photo by author.

The Slate Roof Bible — Chapter 10 — International Slate 103

 Georg Guntermann, manager of the Magog slate mine and
production facility near Bad Fredeburg, Germany, leads the author
into the gaping maw of the mine (top, right), for a long walk down its
wet throat to a depth of approximately 900 feet where the slate is
being extracted.

Rathscheck Company in Mayen, Germany, maintains a

stock of roofing slates from around the world (right), here inspected
by Dr. Uwe Dittmar. Dr. Dittmar examines Rathscheck’s own slate
(below), deep in their Katzenberg Mine near Mayen, a mine with 27
km of tunnels and a record of slate production since 1362. See
Chapter 14 for more information about German slating styles and
techniques.
Photos by author.

104 The Slate Roof Bible — Chapter 10 — International Slate

teeming with eager, hard-working young men, how- ed Chinese slates is a black variety, which can be
ever, who were being trained in a respected very hard and can perform quite well under ASTM
European trade. Master level training was also testing. As in all slate-producing areas of the world,
offered for those roofers who had already gone into a range of slate qualities can be found in China.
the roofing industry and gained sufficient experi- Some of the slate quarried there has a record of
ence on the job. longevity observable on the older buildings still
Perhaps what most sets the Germans apart standing there today. Other quarries are so new that
from the rest of the world in the realm of slate roof- no track record for their slate has yet been estab-
ing is the unique style of slating seen everywhere on lished. Quality control can also vary significantly
Germany’s charming Tudor-style dwellings. from producer to producer. It is always wise to buy
Altdeutsche and its very similar modern cousin, slates from a known source (quarry) that has a good
Schuppen (fish-scale) slating is unheard of in the business reputation, and this is especially true when
United States, although such roofs can be seen buying slates from abroad; otherwise what you order
throughout Europe wherever German slaters have and what you get may be two entirely different
been employed to display their incredible craft. The things! For best results when buying in quantity, it is
slating style is unique in that the slate is in the shape important either to visit the slate mills yourself or
of a parallelogram rather than a rectangle, and laid have a reliable person available to you in China who
on the roof with one side and the top overlapped in knows what’s going on.
such a manner that only one corner is exposed. This Commercial development of Chinese roof-
corner is always cut into a curved shape, usually by ing slate for western markets only began in the
hand with a slater’s hammer and stake on the job 1980s. Until then, Chinese slates had been used
site (in the Altdeutsche method), or manufactured mostly in remote villages. As the Chinese economy
as such in the Schuppen method. Each piece of roof- develops, State Owned Enterprises (through which
ing slate is nailed in place with three nails onto a most business was previously transacted in China)
solid board roof deck rather than the lath roofs more are allowing more private companies to use their
common in the UK and other parts of Europe. The quarries or lease the mineral rights. This has caused
result is a totally unique style that enables the roofer more Chinese slate to become available on the world
to dispense with much of the exposed flashing metal market. Some new slate deposits have been discov-
common to American roofs and instead simply wrap ered accidentally during construction of large infra-
the slates over the valleys and dormers in a smooth, structure projects in China.
sweeping style that is both artistic and functional. There are numerous sources of slate in
Needless to say, this German slating technique China, including the following provinces: Beijing,
requires specific training and time to master, which Hebei, Hubei, Jiangxi, Shaanxi, Yunnan and
is perhaps why it is not more widespread throughout Sichuan.
the world when compared to standard lap rectangu- Currently, 50% of the export market origi-
lar slating — a much easier, simpler, but less exotic nates from Hebei, which is the province that
system of roofing. includes Beijing. Beijing slate from Men Tou Gou
With 2,300 years of tradition behind them has reportedly been used for roofing for over 500
dating back to the Romans, the Germans have kept
alive and perfected a unique style of slating that is
incredible and beautiful. Examples of the fine art of
German slating can be found in Chapter 14.

CHINA
Special thanks to John Wright, IEL International, Hong Kong (www.iel.com.hk/slate); and to
John Xue (johnchina@china.com).

Chinese roofing slates have become a com-

mon sight in American and European roofing slate
markets, as China continues to grow as a major pro-
ducer and world supplier of roofing slates.
Although Chinese slate is available in many colors
ranging from black to red, yellow, green, gray, blue
and purple, one of the most widely used and respect-
The Slate Roof Bible — Chapter 10 — International Slate 105
 s A Chinese black-slate quarry in the North of Jiangxi province in full operation is busy with workers,
one of whom splits individual roof slates from a block (below).

106 The Slate Roof Bible — Chapter 10 — International Slate

 CHINESE SLATE

Back-breaking work greets Chinese slate quarry

workers (top left) as they move an extremely
heavy piece of stone. Slate is being punched for
nail holes (top right), trimmed (above) and cut
from blocks (above right) at Chinese quarries.

The finished product awaits shipment (right).

All China photos provided courtesy of

John Wright, IEL International, Hong Kong
(www.iel.com.hk/slate).

The Slate Roof Bible — Chapter 10 — International Slate 107

years. About 80% of the production is now exported two main transport hubs are Hong Kong and
for flooring, walls, roofing, etc. The color varies from Beijing. Any business person planning to visit China
black to black/gray to purple, green, jade green, etc. will either need to speak Mandarin or have an inter-
The green slate from Fang Shan is very popular, preter. English is widely spoken in Beijing, Xian,
especially for use in billiards tables. Shanghai and elsewhere in tourist areas, but as soon
Zhu Xi and Zhu Shan areas in the Hubei as you get off the beaten path, you will have great
Province are supposed to have the largest reserve of difficulty communicating without some knowledge
Cambrian, Ordovician and Silurian slates. Colors of the language.
include black, gray, bean green and green.
Unfortunately, the overburden is quite large, averag- ITALY
ing 50 meters. “Here is where slate was born.”
The Shaanxi slate vein runs for over 200 km
east-west, averaging 50 km wide. Most of the slate A visit to the Italian slate region will take the
was formed during the Ordovician and Cambrian traveler over rugged, mountainous terrain in a jun-
periods, 400 to 600 million years ago. Here you will gle-like coastal setting with very winding, narrow
find the beautiful, high quality black slate, which roads. Ancient villages clinging to steep hillsides or
comprises 50% of the national production capacity. nestled in misty valleys are dotted with pastel stuc-
People from all over the world have come to visit the co houses. The slate or tile roofed abodes overlook
area for sourcing, purchasing and investment in spectacular views of the Gulf of Tegullio where palm
slate. trees dot the coastline.
Many Chinese quarries are served by poor The author had the pleasure of being intro-
transport systems which makes getting the material duced to Italian slate by Vittorio Terzo Arata
to port costly. Exporting quarries are often located (founder and president) and Sophie Boulay (export
close to a main navigable river such as the Yangtze manager) of Euroslate in Orero, Italy. Vittorio is a
or Yellow River or near rail lines. During the wiry, fit, 70-year-old, with dark glasses and a bristly,
Chinese New Year in late January or February gray crew cut, who speaks English fairly well. An
(depending on the lunar cycle), some quarries may animated, energetic man for his age, Vittorio was
close for a month, meaning production can come to dressed in work boots with clothes that were obvi-
a standstill during this period. ously being used for hands-on work in the mill. You
China is almost exactly the same size as the couldn’t have picked him out from any other worker
U.S. with similar climate differences. The best time by his clothes, despite the fact that he owned and
to visit is in the spring (March/April) or autumn operated three slate factories. Vittorio is not a suit-
(Sept/Oct). Winters can be very cold and summers and-tie type — he apparently gained his success by
extremely hot. Most major cities have air trans- working side by side with the others in his company.
portation and the rail system is efficient, although His grandfather, Vittorio I, started the first slate mill
even 1st class can be basic. Roads are variable, rang- there in 1880.
ing from highways to muddy tracks. Consequently, Euroslate’s primary product is billiards
it can take up to 5 days to reach some quarries. The slates, with the claim to being the largest billiards
slate factory in the world,
producing 100 billiards
slate sets per day, pocket
holes and all, ready to ship
out. It’s all done on an auto-
mated factory line designed
by Vittorio. They also hand
split slates for that natural
cleaved look for table tops
and flooring, and they do
make roofing slates. The
ones in stock at the time
were with all sawn edges.
Their roofing slates tend to
be larger in size, 1 cm thick
108 The Slate Roof Bible — Chapter 10 — International Slate
(about 1/2 inch), and a typical size is 57x13 Vittorio Terzo Arata of Euroslate, and Orion Jenkins, the author’s son, gaze
across the rugged terrain of northern Italy (below), where the distinctive black
cm (about 12x24 inches), with no nail holes. slate is quarried. Sophie Boulay and a worker at Euroslate inspect the roofing
Vittorio insists that hooking them in place slate before palleting (center). Italian slates are known for their “weathering” char-
with stainless steel hooks is the best installa- acteristics which can create a beautiful roof (bottom). Photos by author.

tion method, and they even have the

machine that makes the hooks from a roll of
wire. Perhaps with this large, thick slate, a
hook would be preferred.
The slate here is black, mined
underground, and easily split into large
sheets. It reminds me of the slate in eastern
Pennsylvania (USA). However, it has a large
amount of calcium in it and much of it turns
white upon exposure to the weather. Many
of the older roofs in the area are made of this
slate, which seems to hold up pretty well,
especially when used with a half-inch thick-
ness. Some of these older roofs are fairly low
slope, perhaps 4:12, but installed with a
head lap that reaches down to the top of the
third slate below, a technique known as
“triple slating” or “triple covering” (see
Chapter 14).
There are reportedly 50 or more
slate mines operating in this area of Italy,
called the Val Fontanabuona (“valley of the
good spring”), just east of Genoa, plus
another 10 or 12 on the French border at the
Arma di Taggia exit off the highway. The
word for slate in Italian is “ardesia.”
According to Vittorio, the Romans
found that slate was being used in this area
20 centuries ago. They called slate
“tegmen,” and the name of the Gulf of
Tegullio is derived from this word. He also
reports that the history of slate in this region
goes back to the bronze age, 4,000 years ago,
according to archeological digs in the village
of Chiavari, nearby. Therefore, says Vittorio,
“Here is where slate was born.” Italians have
made billiards slates for three centuries.
Vittorio’s mine is underground with
access through a tunnel that begins at the
very top of a mountain reached via a wind-
ing, narrow, overgrown road. You can drive
right down into the throat of the mine and
see the men extracting the slate blocks deep
inside. The blocks are covered with a layer
of mud and then a sheet of plastic before
being taken out of the mine and to the mill,
in order to preserve the natural moisture
and therefore the best splitting qualities.
The mine is characterized by huge, solid
The Slate Roof Bible — Chapter 10 — International Slate 109
slate pillars that are left in place in order to support dangerous in the mining industries. In 1892, six
the roof, each about 30 meters square. For more men out of 794 employed in the Angers mine were
information about Italian slate, see Chapter 14. killed, or a proportion of 7.56 per 1,000, while in the
same year the proportion in coal mines was 1.18 in
FRANCE 1,000, and, in all the mines and quarries of France,
1.09 in 1,000.
Angers is a A Scientific American Supplement of 1894
city in northwest- describes the making of roof slate in Angers in this
ern France, capi- manner: “The working of the slate for roofing must be
tal of the depart- done in situ before the material has dried, and, in losing
ment of Maine-et- its water, has lost also its fissility. The block is first slit into
Loire, located 191 thick plates by means of a chisel. Then the slitter, seated
miles southwest under a wind screen, his feet incased in thick sabots and
of Paris at the his legs wrapped with rags to prevent him from wound-
confluence of the ing himself, places the fragment of schist between his legs,
river Loire and and, provided with a very thin chisel and a mallet, strikes
the Maine. With the edge in order to detach sheets from it. All that has to
a reputation for be done then is to give this sheet its proper form and size.
being one of France’s most pleasant cities (pop. This is done by means of a plane iron–very heavy iron
136,038 in 1982), Angers is known for its wine and knife, whose extremity is shored into a ring and which
the famous Cointreau liqueur — and for its slate. turns down against the edge of a block. It is estimated
France is the world’s largest consumer of roof- that an outside laborer earns from fifty-five to seventy
ing slate, utilizing not only their own locally mined cents a day, and a pitman from sixty to eighty cents.”
slate, but also imported slates, especially the black “In 1893, the slate quarries of Maine-et-Loire
Spanish slates, which are similar to French slates gave employment to 1,034 inside and 2,185 outside labor-
(Spain is currently the world’s largest producer of
roofing slates). The French black slate (also Partial reproduction of an old article about the Angers slate mines.
described as “blue-black”) is mined near Angers at
the Fresnais Mine in Trelaze in the beautiful Loire
River Valley. This “Grade A” material has been used
as roofing for over 500 years, and today has a repu-
tation for being very consistent in thickness. A tonne
of this slate equals approximately 3 squares (300
square feet of roof coverage). There are five or six
thousand companies doing slate roof installation in
France today, a country with a population of about
60 million people. Angers is known as “Black
Angers” or the “Black City” for the black slate roofs
that cover the entire area. There is a roofing school
in Angers known as the Ecole Superieure
Couverture at Rue Darwin, Belle-beille.
The evolution of the slate industry in France
parallels that of the UK, with the most progress
accomplished after the mid 1800s. Viollet-le-Duc's
Dictionnaire contains accounts of slate roofing in
Angers from the eleventh century, and slate became
commonplace in France by 1200. By the end of the
1800s, according to Planat's Encyclopedie, French
quarries were located in Angers and Poligny, where
gray and dark blue slates were mined.
French slate quarries were some of the most
Opposite page: Castle in Angers, France with local slate on the roof. (not continued)
Photo by author.

110 The Slate Roof Bible — Chapter 10 — International Slate

The Slate Roof Bible — Chapter 10 — International Slate 111
ers — say altogether 3,219, of whom 1,511 were slitters. opposed to an open quarry). Westmorland Green
In 1891, a total of 2,749 laborers were divided into 2,121 Slate is taken from beneath the hills in eleven miles
for the center of Angers (Trelaze), 109 for the Foret and of tunnels. Quarrying was taking place here by the
135 for Misengrain. During the year these 2,749 laborers 1750s, and from 1833, development expanded with
produced 159,820,047 slates, worth $710,650.” underground mines as well as open quarries. The
Slate is still actively mined in the Angers Buttermere Green Slate Company was established
area of France today. in 1879, but slate mining and quarrying ceased in
1986, then restarted in February of 1997.
THE UK AND IRELAND British slate quarries reached their peak in
the late 1870s with an annual production of half a
IRELAND million tons, 90% of which came from the 670 Welsh
quarries operating at the time. By the year 2000,
Roof slate was quarried in Ireland as late as nine Welsh quarries were producing 40,000 tons
the 1930s. Slate mined in Ireland included a fine annually.
slate similar to Welsh slate near Newtownards, Co. Despite the UK’s long history of slate pro-
Down; a coarse and heavy slate near Kilrush in Co. duction and slate roofing, today natural slate
Clare, and slate in Killaloe, also in Co. Clare. A accounts for only 7% of total roofing products used
blue-black slate was quarried in Valentia Island (Co. there, which includes locally quarried material and
Kerry); a softer, greenish gray slate near Ross, recycled slates as well as imported slates. Concrete
Wexford and Wicklow in Waterford County; a low- tiles now make up the bulk of the roofing at 72%,
quality clay slate near Westport was wrestled from artificial slates make up 14%, and clay tiles make up
the ground in County Mayo; and more slate was 6%. The balance (1%) is made up of metal roofing or
removed from the earth at Clonkilty in Co. Cork. other shingles.
Extensive quarry operations also took place at
Curraghbally, Co. Clare and Portroe, Co. Tipperary SCOTLAND
where 10,000 tons per year were being produced in
the 1840s. Bluish-gray slates were also quarried near Scotland has its own slate roofing history
Ashford Bridge, Co. Wicklow. dating back to the mid 1500s. Production levels rose
to 25 to 30 million slates per year at its peak at the
ENGLAND AND WALES end of the 19th century, employing thereby 1,000 to
1,500 men. By 1937, this had declined to 10 million
For an in-depth look at Welsh slate history, slates and 370 men. By World War II, roofing slate
please refer to Chapter 4. The UK still has 36 oper- production was neg-
ational, natural slate quarries, according to a year ligible, and by the
2000 publication by Historic Scotland. These are mid-1960s slate pro-
located in three main slate producing regions of the duction in Scotland
UK including Wales, Cornwall and the Lake had come to an end.
District. The largest of these are in Wales and are Scottish
operated by Alfred MacAlpine Ltd., in north Wales slates tend to be
at Bethesda. Other Welsh quarries are located at rough, course, thick,
Blaenau Ffestiniog, including Cwt-y-Bugail, and extremely
Ffestiniog, Gloddfa Ganol Slate Mine and Nantile. durable, perhaps
England’s main quarries outside Wales are owing to the great
in Cornwall (primarily the Delabole Quarry) and in geological age of the
the Lake District (Burlington and Kirkstone quar- slates from the west
ries). Burlington slate from Kirby-in-Furness, coast of Scotland —
Cumbria (the Lake District) of northern England, is at 650 million years,
either a “Blue-Grey” slate or a “Westmoreland the oldest in the UK.
Green” slate. These popular slates have been used Scottish slates are
for over 300 years. traditionally center
Also in the Lake District, the Buttermere nailed (single nail at
and Westmorland Green Slate Company Limited is the top center of the
now England's only underground slate mine (as slate) onto a fully
112 The Slate Roof Bible — Chapter 10 — International Slate
boarded roof deck, as described in Chapter
14. Most of the slate found in Scotland
comes from the Grampian Highlands, bor-
dered on the south by the Highland
Boundary Fault, or Highland border.
The four main slate producing local-
ities were:
1) Ballachulish, which produced a dark
gray/blue slate with a distinctive, well-
marked grain referred to as lineation;
2) Easedale Islands, producing a dark
blue/gray slate occasionally showing a
brown weathering, with a marked grain;
3) The Highland Boundary Fault, produc-
ing a variety of colors including blue, gray,
green, purple and mottled, generally lighter
than the slates of the west Highlands. These
slates have the finest texture in Scotland,
almost entirely without grain.
4) The Banff-Aberdeen Slate Belts in the
northeast of Scotland, including the
Macduff quarries, producing a rough,
course, dark blue/gray slate without grain.
The Scottish government has shown
a great interest in the historic preservation
of its nation’s antiquities and has published

Delabole slate roof in Cornwall, England (top, right).

Welsh slate on a cottage in western Wales (right).
Lake District slate on a barn in northwest England
(below).
All photos by Dave Starkie.

The Slate Roof Bible — Chapter 10 — International Slate 113

 comprehensive books on Scottish slate quarries and
Scottish slate (see reference section). These are
available from the Publications Department,
Historic Scotland, Longmore House, Salisbury
Place, Edinburgh EH9 1SH, Scotland (www.his-
toric-scotland.gov.uk).

SPAIN

Last, but not least, Spain is the big boy on

the world’s roof slate production block, producing
more roofing slate than any other country in the
world, with slate quarries scattered across the nation
and particularly concentrated in the northwest in
the provinces of Orense and Leon. The most com-
mon Spanish slate seen in the U.S. is the smooth-
grained, jet black variety that is also prized through-
out Europe.
Spanish slate had begun to develop a ques-
tionable reputation in the U.S. at one time, due to
imports of poor quality materials that were begin-
ning to give Spanish slate a bad name (a similar sit-
uation occurred with Chinese slates too, by the way.)
Apparently, American importers were just buying
the cheapest slate they could get without research-
s Easedale slate on a Scottish house built in 1785.
t Working woman at the Franvisa slate mill, northwest Spain.
ing the quarries of origin or the characteristics of the
Photos by author. slate. As a result, they were receiving slates with
high pyrite levels that would develop unsightly red
rust spots in only a year, slates that were too thin to
nail onto a roof, and/or slates with no nail holes at
all. Many roofing contractors in the United States do
not realize that slates produced for European mar-
kets are quite different from those preferred in the
U.S. market. For example, European (especially
French and German) slates tend to be thinner than
American slates, and European slates are frequently
produced without nail holes as Europeans often
don’t nail slates — they install them with slate hooks
instead. Things have changed somewhat over the
years, however, and now a high degree of quality
control at the Spanish end and reputable suppliers
at the American end have introduced high quality
Spanish slates to the American market.
Some Spanish quarries produce slates par-
ticularly for the American market. These slates tend
to be thicker than the European variety and they’re
punched with nail holes for a 3” or 4” headlap.
There are quite a few companies marketing roof
slate in Spain today, some of which are listed in the
Industry Resource Guide at the back of this book.

114 The Slate Roof Bible — Chapter 10 — International Slate

 Province Slate Produced

Lugo . . . . . . . . . . . . . .gray, green, multicolor

Leon . . . . . . . . . . . . . .black, gray
Guipuzcoa . . . . . . . . .gray
Barcelona . . . . . . . . . .multicolor
Segovia . . . . . . . . . . . .gray, multicolor
Badajoz . . . . . . . . . . . .black
Zamora . . . . . . . . . . . .black
Orense . . . . . . . . . . . .black, gray
La Coruna . . . . . . . . . .gray

Source: Piedras Naturales, Anuario 1997

s The rugged mountains of northwestern Spain yield a high quality black slate produced by (among others) Franvisa slate company (Pizarras
Franvisa). Franvisa’s quarry is at the top right corner of the photo on the mountainside. Pilar Cubelos Martin (left) and Francisco Vime Losada,
of Franvisa, inspect the pallets of roofing slate awaiting export. Top: A typical Spanish slate mill.
Photos by author.

The Slate Roof Bible — Chapter 10 — International Slate 115

 THE SLATE ROOF BIBLE
SECOND EDITION

Part II

Installing Slate Roofs

• What’s It Like to Work on a Slate Roof?
• Chapter 11: Safety First
• Chapter 12: Basic Tools and Equipment
• Chapter 13: Installing Slate Roofs
• Chapter 14: European Slating Methods
• Chapter 15: Roof Inscriptions and Designs
• Chapter 16: Recycling Slate Roofs

Bats were rudely evicted, live wasp nests were destroyed, and feet were baked — all in a summer morning’s
work on a slate roof. At 95 degrees Fahrenheit in the shade, roof soot clings to sweat as evidenced by three
slaters taking a merciful lunch break.

Photo by author.

116 The Slate Roof Bible

 Foreword – Part II you’re not afraid of bats or hornets, but when you
grab the can of spray you wince and drop it to the
floor. The temperature in the room has risen to
WHAT’S IT LIKE TO WORK ON AN 1350F and the can is literally too hot to touch, so you
OLD SLATE ROOF? put on some gloves, despite the heat, grab the spray,
sneak back to your desk and spray the hell out of the
A friend once asked what it was like to work yellow jackets, while muttering some vengeful
on slate roofs. He worked in an office and was think- obscenities. Then you fling open a window to get
ing about quitting his job and was even considering some air and, luckily, the bat flies out.
taking up slate roofing as a trade. I was certain that Now that most of the bees have been killed,
he would immediately change his mind if he had you sit back down at your desk, being careful not to
any idea of what slaters go through on an average touch anything metallic without insulating yourself
summer day, so I decided to describe the work in from the hot surfaces. Only now you find that your
terms he would probably understand: typewriter is gone, and in its place are steel and iron
Imagine you’re in your office one fine sum- hand tools, including a formidable looking hammer
mer day, sitting at your desk, comfortably typing and a long tool that looks like a sword. Your co-work-
away at your computer, listening to the hum of the er informs you that your job henceforth will be to
air conditioner while your wonderful co-worker gra- beat on the sword as hard as you can with the ham-
ciously brings you a freshly brewed cup of coffee. mer. “And don’t cut yourself on the sharp edges!”
Then the air conditioner dies. You continue “Sharp edges of what!?” you ask.
typing until you realize that not only has the air con- “Of the slate and sheet metal, of course!” she
ditioner stopped, but someone has turned on the fur- impatiently replies. “They can be sharp as razor
nace! The temperature rises, passing 1000 F while blades, dummy!”
sweat beads on your brow. Then you become aware Sure enough, you nick your finger the first
that now someone has turned on a humidifier. The time you impatiently beat on the slate ripper, so you
heat is so intense and muggy that soon you start rip- stop and wrap the bleeding appendage with a band-
ping off clothing, flinging your suit coat and tie to age, wondering if maybe you should have washed
the floor, along with your shirt. Sweat is now pour- your filthy hand first. When you resume your labor
ing into your eyes, blinding you, so you grab a rag you realize that your desk is covered with a thick
and wrap it around your forehead. Your co-worker layer of bat droppings, and you’ve been grinding the
informs you that this is now your new work environ- guano into the skin of your arms. Just when you’ve
ment, and you must do your day-to-day tasks under stopped to ponder this new discovery, an amazing,
these sweltering conditions, whether you like it or unexpected and terrifying thing happens: the floor
not. She hands you a jug of drinking water, which of the room suddenly heaves into the air, tilting at a
you desperately chug. 45 degree angle! Everything in the room goes flying
Stunned by this new development, you pull downhill! Your desk somehow remains attached to
open your desk drawer, hoping to find something to the “floor,” however, so you cling to it for dear life.
fan yourself with, when a cloud of black dust flies in Your co-worker yells up from the bottom of
your face covering your sweaty skin. You now look the heap shouting that she has a hook ladder you can
like a coal miner as you take a tissue and wipe the hook to the top of the room so you have something
dirt granules out of your eyes so you can continue to to stand on. She carefully slides the ladder up the
work. You pull your drawer open further and a slanting floor past your desk and somehow it hooks
swarm of yellow jackets flies out mad as hell as they at the high end of the room. You carefully stand on
go for your face. Some lodge in your hair as you fran- the ladder, crouched low and leaning to compensate
tically swat at them. In a panic, you fall backward in for the 45 degree angle of your new work surface.
your chair, scrambling on the floor to get away. “Back to work!” she yells up, “but here, take these.”
You run for the closet to get a can of hornet She throws up a pair of rubber-soled shoes. You
spray, and as you poke around looking for the spray, slowly take a seated position on the hook ladder, and
pounding the buzzing bees in your hair, a bat flies remove your wing tips. The soft, lightweight shoes
out of nowhere, startling you. You duck as the bat give you better traction.
skims past your head chirping insanely, then you Back to work!? OK. But you find that the tilt-
watch it assume a circling pattern in the office as it ed “floor” is so hot you can’t touch it and you can’t
flies around looking for a place to land. Fortunately, even rest your foot on it to stabilize yourself, because

The Slate Roof Bible 117

it burns the soles of your feet right through the ning begins to flash. You realize you’ve suddenly
shoes. You must keep your entire body perched only become a human lightning rod, so you scramble
on the aluminum hook ladder, which holds you an down the hook ladder and hasten down the ground
inch or two off the floor surface, now radiating heat ladder, fearing for your life as you rush to get off the
like a heat lamp. You take off your headband and roof. Rain begins to pelt down and the wet roof sur-
wipe your sweaty forehead, clinging with one gloved face turns as slick as ice. Your co-worker has enough
hand to the ladder. Then you replace the sweatband sense to get down ahead of you, so you join him on
and grab the iron implements. The last thing you’re the ground where you seek shelter together. The
worried about right now is bats or bees, although pouring rain has cooled things off, washed some of
you don’t want to be startled under these conditions the dirt off your face, and now you’ve got your feet
and risk falling. So you move slowly and deliberate- back on the ground. Your prayers of gratitude are
ly as you once again begin beating as hard as you can suddenly interrupted with a shocking thought —
on the iron tools in your hands. you forgot to close the gaping hole you left in the
But you can’t relax yet. Suddenly, the entire roof and now it’s raining buckets!
work environment lurches forty feet in the air and You’d give anything for a nice, cushy office
all the walls and ceilings drop away, leaving you out job again — wouldn’t you?
in the beating sun on a steep slope with your hind-
end flapping in the wind. The heat, dirt, bats, bees [Unfortunately, the above scenario is not much of an
and humidity remain with you, however, and now exaggeration. Interestingly enough, it’s a true story. The
you have the blasting sun beating down on you too. office worker was apparently a masochist at heart,
Although there is an occasional breeze, it doesn’t because he did quit his middle management position at
seem to do anything but blow the heat around. With the factory where he worked, despite my earnest discour-
both hands clinging to the ladder, you look over your agement; and now, seven years later, he is a very success-
shoulder and see your co-worker standing way down ful slate roof restoration contractor. Because he started
there on the ground. “No more pushing paper for out in the slate roofing business on the author’s crew, he
you,” she yells up. “You need to come down here and managed to get his photo in this book in more places than
carry up these slabs of stone!” one, including slating an octagonal tower, shown in
“What! How many?” Chapter Eight.]
“Oh, a ton or so,” she says, without exagger-
ating.
You are now asking yourself if
your miserable working conditions can
possibly be any worse. You can’t imagine
what else can go wrong when suddenly
you smell something, and it doesn’t smell
good. “Oh god, what’s that?” you ask your-
self out loud. “What’s what?” replies your
co-worker in a gruff voice. You’re aston-
ished to discover that your gracious, gen-
tle, attractive co-worker is now clinging to
the same hook ladder you’re clinging to,
and she’s had a horrible sex change opera-
tion. He now bears a striking resemblance
to a species of lower primate. Worse, he
has developed a notable proclivity for the
use of expletives in his language. The
smell? As luck would have it, your co-
worker is now listed in the Guinness Book
of World Records as the world’s greatest
source of natural gas!
Just at that moment, a thunder-
storm blows in out of nowhere and light-

118 The Slate Roof Bible

 Chapter Eleven

SAFETY FIRST

M
ost old slate roofs are in need of was working happily away, his wife had a sudden
repair, and ninety percent of what’s and unexpected urge to go shopping. Unfortunately,
involved in repairing them is sim- the man had neglected to inform his wife of his
ply a willingness to climb. If a slate roof could be ingenious safety precautions. She hopped in the car
laid down on the ground, almost anyone would be and took off without a second thought. This story
able to climb on it and repair it. But it’s not down was reported in the newspaper, and although the
here — it’s up there. This is where the element of man was yanked off the roof and dragged down the
risk comes into play, and safety precautions must be street, he reportedly survived, though his final con-
taken seriously. dition was unclear.
You can actually walk out the front door of Even though this man had safety in mind, he
your house, trip on your shoe string, fall, hit your went about it in the wrong way. This illustrates a
head on a rock, and die. If you fall from a height of case where a person violated all the rules of safety —
six feet, same story. If you fall from a roof top . . . he had the wrong attitude (too careless), didn’t
well, let’s not imagine the consequences, but let’s be understand the potential hazards (in this case, not
aware of the possibility and take measures to pre- informing his wife), and he didn’t use the proper
vent any sort of accident. The author, at the time of equipment (ropes wrapped around one’s waist are a
this writing, has worked on slate roofs for nearly 35 mistake).
years and will try to pass on some insight and expe-
rience related to safety when working on the high, 1) PROPER ATTITUDE
steep, slippery surfaces characteristic of slate roofs.
But first the obligatory disclaimer. I’m pass- First, and perhaps most important, safety is
ing on this information for educational purposes, a mental attitude. You must be careful and cautious.
but I can’t be held responsible for the actions of oth- You must realize that you are responsible for your
ers. The author cannot control the attitude of the own safety, and if you fall or hurt yourself you, and
reader, nor sharpen his or her senses. You are perhaps your family as well, must suffer. If you don’t
responsible for that, and if you trip on your shoe- take care of yourself, no one is going to do it for you.
string on the way to the ladder, don’t blame me. You probably understand this when driving a car or
When working at heights, you must proceed with when chopping vegetables at the kitchen counter;
utmost care and caution, and you must take full per- you must understand this when climbing on a roof.
sonal responsibility for yourself. Read all instructions The man in the incident above could have at least
carefully, and follow the recommendations of the opened the hood of the car to indicate that it should-
manufacturer of any roofing tools and/or equip- n’t be moved (or he could have put a note on the
ment. Be aware of safety codes and regulations in steering wheel). You don’t want to be telling yourself
your area, and do not proceed with any roofing work what you should have done — instead, think ahead!
unless and until you, and you alone, will take full Never rely on someone else’s judgment about
responsibility for your actions. whether a situation is safe or
Perhaps you heard the true not (unless you’re an appren-
story of the man who wanted to tice working alongside a master
work on his roof but feared for his roofer). Use your own judg-
safety. He tied a stout rope to the ment. If you don’t feel safe in
rear bumper of his car, flung the any given situation, don’t pro-
rope up over the peak of his house, 1. KEEP A SAFETY ATTITUDE. ceed. Stop and do whatever is
then climbed up a ladder on the necessary to improve the safe-
other side of the house and tied the 2. KNOW THE HAZARDS. ty of the situation to your satis-
rope around his waist. While he 3. USE PROPER EQUIPMENT. faction, then continue.

The Slate Roof Bible — Chapter 11 — Safety 119

 Never be in a hurry when working on a slate jackets look sort of like honey bees, and many peo-
roof. It only takes one slip and you’re history. This ple can’t tell them apart, but honey bees are fuzzy
issue about attitude cannot be overemphasized. and yellow jackets aren’t. Also, yellow jackets die off
Keep your eyes and ears open at all times when in the winter except for the queen, who hibernates and
working at heights. starts a new nest in the spring. Therefore, yellow
Always make certain the correct equipment jackets don’t nest in the same spot from one year to
is being properly used and always be aware of the the next, but they will nest in the same house. Honey
potential hazards. Find them before they find you, bees, on the other hand, usually stay put in the same
and prevent accidents before they happen. nest year after year.
One reason yellow jackets are such a hazard
2) BE AWARE OF THE ROOFTOP HAZARDS is because they’re just plain mean. They’ll go out of
their way to sting you. I’ve had them fly from under
There are a number of hazards that exist on the eaves clear over the peak of the house to the
old slate roofs that you must memorize and look for other side of the roof just to try, successfully, to sting
every time you get on any roof. They can be summed me. When you’re hanging on a ladder and perched
up as: BEES, BATS, CHIMNEYS, WIND, LIGHT- precariously at some considerable height, you don’t
NING, ELECTRICAL WIRES and CO-WORK- want a bunch of yellow jackets flying in your face.
ERS. It’s a natural reaction to recoil, swat like hell and
run when attacked by bees. You can’t do that when
BEES on a ladder or a roof, so make sure you don’t put
yourself in that situation. If by chance a bee does fly
Bees are one of the worst hazards on old slate at you, it is critical that you hang on to whatever it is
roofs. One recent summer in a local town, a man was you’re holding on to, and don’t panic! Leave the area
found at the bottom of a ladder riddled with bee as quickly as possible without being reckless. Don’t
stings, and dead. He had probably set his ladder up let a puny bee force you to meet your maker.
in front of a nest of yellow jackets, which may not I might add that some people are allergic to
have been apparent to him, and when they attacked bee stings, and yellow jacket stings are among the
him he panicked, fell off the ladder and thereby most venomous, according to my observations. A
made his last mistake. You must always look for friend of mine was stung in the forehead by one, and
nests of bees during the summer months on any her head swelled up like a pumpkin. She looked like
house, rural or urban, before even putting up a lad- something out of a horror movie for about two days.
der. There are generally seven types of common My neighbor was stung by one and his whole body
bees: yellow jackets, honey bees, paper wasps, bald- swelled up, and he had trouble breathing for hours.
faced (white-faced) hornets, bumble bees, carpenter I have worked on slate roofs since 1968 and have
bees and mud daubers. never been stung by any bee except yellow jackets
The first and worst are yellow jackets. These and honey bees, and only once or twice. I am not
are small, mean and nasty wasps that live in highly allergic to them and was once stung by 17 yellow
populated paper nests sometimes shaped like foot- jackets as a teenager (not on a roof) with no adverse
balls, but the nests are usually not visible — they’re reaction. But now I spot them before they spot me,
in the wall or roof of the house. Sometimes the nests and I avoid them if I can. If I can’t avoid them, I
are in the ground and yellow jackets are sometimes spray them with hornet spray if I can get close
called ground bees (there are other types of ground enough to spray the nest itself. It does no good to
bees, too). Sometimes the nests are exposed under just spray the bees because there are thousands of
the eaves of the building anyplace from down on the them, but if you can knock out the nest the remain-
porch to the very top of a three story house. Yellow ing live bees will usually leave you alone (they
become demoralized and disoriented after the queen
has died).
Being a honeybee keeper, I can safely say
that the best defense against harmful bees is aware-
ness of their habits, patterns and weaknesses, avoid-
Bees are one of the most serious hazards when working on ance of them, or eradication if all else fails. I don’t
slate roofs. Yellow jackets and white-faced hornets are recommend hunting down and killing every yellow
especially aggressive.

120 The Slate Roof Bible — Chapter 11 — Safety

jacket nest you can find, because then you’re just net spray. Finally, if you have to approach a nest
asking for trouble, but if you do need to kill them, closely to spray it, wear coveralls, gloves, and a bee
here are some tips: veil. A prudent roofer will always keep these essen-
Most of the bees will be out working on a tial materials in his work truck. They may save you
sunny day. That’s how you can locate the nest — from bee stings many a time. If the nest is in the
look for the insects flying toward and away from the ground, you can pour a flammable liquid down the
house. When you see insects flying back and forth hole and light it, unless the hole is near a house or
like that, you can trace their flight path back to the other object that you don’t want to burn to the
house and either find the nest, or you may see a ground!
small hole under a window sill, between some clap- Honeybees aren’t as mean as yellow jackets,
boards, in a chimney, or even on the roof itself where but will defend their nest just as violently if need be.
a slate is missing. You’ll see the bees flying in and Their nests are rarely exposed and are made of wax
out of the hole. Once you’ve located the nest (almost cells where the bees store honey and hatch out
every old farmhouse and many city houses have young. You can locate their nests in the same man-
them), stay away from it. Do not put a ladder up in ner as yellow jacket nests — by looking for their fly-
front of a bee flyway. Remember that bees, like some way. You will see them flying in and out of a hole in
people, are friendliest on sunny, dry days, and mean- the building.
est on cloudy and muggy days. This is a fact. So on a Again, their behavior is affected by the
sunny, dry day you may be able to work closer to a weather, and they don’t want you anywhere near
bee nest than on a bad weather day, but don’t count on their nest when rain is impending and humidity is
it. rising, probably because their nests are vulnerable to
Because the bees are working during the day, rain. They, too, are friendliest during sunny, dry
the ideal time to spray the nest is at night when weather. Honeybees (and yellow jackets) tend to
they’re all home. Unfortunately, night time is the attack black and rough surfaces first. That’s why
hardest time to spray because you can’t see anything, they go for your hair. Maybe they evolved in such a
so dusk or dawn may have to do. Otherwise, you can manner that they think everybody is a bear trying to
spray them during the day and expect to see bees steal honey, and so they dive for that part of you that
returning to the nest all day and swarming around looks like a bear. Knowing this, you would never
the door to their nest, wondering what the heck hap- approach a bee nest wearing dark, rough clothing.
pened to their home. When they realize their home Beekeepers wear smooth, white coveralls.
and queen have been destroyed they probably won’t Honeybees generally will not go out of their way to
attack you in a mad frenzy, as they’re most defensive sting you like yellow jackets will, but if the weather’s
when protecting their queen. Once the queen is bad and you resemble a bear — look out!
dead, the bees don’t seem to know what to do. I have never destroyed a honeybee nest and
However, they may still sting, so watch out. probably never will — they’re beneficial insects. It’s
The yellow jacket nest starts out in the easier to wear protective clothing around them than
spring with only one bee — the queen. She builds a it is to try to kill them. A full grown honeybee nest
small paper nest about the size of a golf ball, then will contain tens of thousands of bees that will polli-
starts laying and hatching eggs. By fall, the nest will nate many flowers, as well as produce much honey
be the size of a football and have thousands of bees and beeswax. But they do live in the walls of old
in it. Obviously, a good time to destroy a nest is in houses where they remain year after year, although
the spring when it is tiny. The longer the nest is they’re not as common as yellow jackets. The solu-
allowed to expand, the more bees it will have and the tion to honeybees is to avoid them. If you can’t, then
more effort it will take to get rid of it. Of course, the wear protective clothing and work around them
bigger a hidden nest gets, the easier it is to locate, when they’re in a good mood.
because there are more bees flying in and out of it. Bald-faced (white-faced) hornets are mean like
Fall is the worst time for roofers where bees are con- yellow jackets. They live in paper nests which can
cerned, because the nests are bloated with bees, and get rather large (football size or bigger) and hang
in September and October, the roof worker needs to down from the eaves of a house, containing as many
be especially vigilant. as 10,000 hornets. I have seen their nests hanging on
Do not try to kill yellow jackets or any other almost anything, including tree branches and brush,
bees with general insect spray — it doesn’t work and and saw one nest sandwiched between two windows,
it just makes the bees mad. Use only wasp and hor- thereby exposing the entire inner workings of the

The Slate Roof Bible — Chapter 11 — Safety 121

hive. These nasty critters can’t be trusted. They’ll ability to startle you, a danger you can’t afford when
come after you aggressively and should be destroyed. working at heights.
Paper wasps are not mean, they just look like Finally, mud daubers are common on old
it. They’re a relatively benign stinging insect. They roofs. They’re long, thin, purplish wasps that nest in
will sting you though, if you disturb their nest. You clumps of mud they build on or in chimneys, under
can get quite close to a paper wasp nest and they flashings, and especially in attics. They’re not mean
won’t come after you unless you vibrate the nest by and are usually not a problem.
banging near it. It is recommended to spray their
nests when you have to work near one because a BATS
number of roofers do get stung by these fellows.
One of my workers was stung by a paper Bats come in various sizes and shapes and
wasp while tying a ladder to a rain gutter. The nest are very common around, in and under old slate
was up under the slate at the eaves, and he stuck his roofs. They are not a danger except that they may
hand practically right in it, then developed an aller- startle you if they fly out at you, and your instinctive
gic reaction when stung. One minute he was normal recoil can knock you off the roof. However, if you’re
and the next he was covered with hives, his face was aware of their presence and expect them, you won’t
swollen, and he was lying on the tailgate of the truck be startled if one does appear.
trying to breathe. I watched another fellow also get Bats love to hang out under ridge metal,
stung in the hand by paper wasps for the same rea- under chimney flashing, in old chimneys (some-
son — reaching under the eaves of a dormer (a times between the bricks), under loose slates, and
favorite spot for paper wasps) without looking first. especially in the attics of old houses. They can get
Another roofer I know fell off the peak of a roof after into the roof through almost any hole, and are
exposing a paper wasp nest while removing ridge almost impossible to keep out. Again, these are ben-
iron. The wasps came flying out at him and he eficial creatures that eat a lot of bugs, so the solution
backed off the roof in panic, falling nearly thirty feet to bats is not to kill them but to learn to live with
off the gable end. He was lucky — he only broke his them. I’ve seen people try getting rid of bats by put-
leg! You must always look under eaves and in any ting mothballs in their attics (not very effective),
area that may hide a nest of bees before putting your and by using electronic pest repellent (might work).
face or hands in it. Remember to find them before Some people swear that you only need to keep a light
they find you! Paper wasps love to build nests under on in the attic to keep them away, but this is hearsay
ridge metal, so always remove ridge metal and other and I can’t vouch for it.
flashings carefully and have a can of hornet spray Bats hibernate in the winter, then become
handy in the summer months. active again when it warms up. In the fall when the
Bumble bees and carpenter bees look very simi- days are cold, bats, like wasps, move in slow motion
lar. They’re round, black and yellow and fuzzy, and and are easily captured. They do have a lot of teeth
they’re usually not mean. Bumble bees live in and might bite, so I don’t recommend handling
colonies often in the ground, while carpenter bees them without gloves. Of course, everyone says they
live in holes they bore in wood. There are large car- carry rabies, but this threat may be exaggerated.
penter bees and small ones. The small ones seem to You can usually locate bats easily because
live in groups, while the large ones are loners. You’ll first, their droppings give off a characteristic odor,
often see the large carpenter bees when on the roof and secondly, the bats themselves give off a familiar
of old buildings, especially barns, because they live high-pitched squeak or chirp when agitated.
there, too. They’re very territorial and will hover in Furthermore, you can hear them scrambling and
the air like a tiny helicopter staring at you from a scratching under ridge metal when you’ve climbed
couple feet away, trying to intimidate you. If any on the roof and disturbed them. On one roof, I
other insect happens to fly past at that moment, the shoved my slate ripper under a broken slate to
carpenter bee will chase after it until it leaves its ter- remove it, and when I pulled the ripper out a live bat
ritory, then it will come back to you as if to ask came out with it! If you have an old house with a
“What the heck are you still doing here?!” I’ve never slate roof, you probably have bats. If you expect
known anyone to be stung by one, although I’ve had them and look for them, they won’t startle you and
to swat a few with my slate ripper just to get rid of cause an accident.
the persistent little devils. Their danger lies in their

122 The Slate Roof Bible — Chapter 11 — Safety

 CHIMNEYS face of a slate roof, and have read that 1400 is not
uncommon. People do keel over from heat stroke,
Never grab onto a chimney for support unless and if you are susceptible to this sort of thing, stay
you’re quite sure that it is solid — most aren’t. Many of off a slate roof during the heat of a summer day.
the old chimneys on slate roofs have soft mortar, and Furthermore, sunburn can lead to skin cancer in
the bricks can easily be lifted apart. This becomes a later years, so protect yourself from excessive, chron-
hazard when someone grabs onto a chimney to ic solar exposure. Rain, dew, and of course frost
steady himself when moving along a ridge, and the make the surface of slate roofs wet and slippery. As
bricks give way. Also, when taking chimneys apart, a rule, never work on a wet or frozen slate roof.
remember that bats do live in them, and sometimes
bees do, too. Find them before they find you. Finally, ELECTRICAL WIRES
chimney swifts (birds) also live inside chimneys in
shelf-like nests fastened to the side of the bricks or Electrical wires are a very serious hazard. If
stone. When you peer down into the top of the chim- your aluminum ladder happens to hit a high-voltage
ney, a startled bird may fly out in your face. Be pre- wire while you’re touching the ladder, you’re dead
pared. — instantly. Electric lines may contain as much as
7,200 volts, or may be stepped down to 2,400 volts
WIND, LIGHTNING, HEAT AND RAIN until the lines reach the transformers located on a
pole near the house, where the voltage is reduced to
Wind is an obvious hazard when working on 110/220 volts. The “high voltage” lines are certain
roofs. It’s much windier on top of a roof than on the death, and the 110/220 lines can also kill, so always
ground, and on very windy days it may be a good be aware of the location of electrical lines and keep
idea to stay completely off the roof. The danger of your aluminum ladders away from them.
wind is magnified when you’re carrying a hook lad- When electrical lines enter the house from a
der up onto a roof, across the roof, or back down off public electric service source, there will always be at
the roof. The wind will catch the ladder and push it, least two lines, and they will attach to the house on
which may cause you to lose your balance. Also, an insulated mount, usually leading to an electrical
wind will readily knock a ground ladder off a house, meter. This differs from telephone lines because
so erected ground ladders must always be tied to the telephones only need a single line (although if the
house to prevent this from happening. Aluminum house has several phones there may be several phone
ladders are light and easily blown down onto a per- lines), and phone lines usually don’t lead to an insu-
son, car, or other property, not to mention the dam- lated mount, and never to an electrical meter. If you
age to the ladder, or the embarrassment to the see lines entering the building you want to work on
stranded roofer. and aren’t sure what they are, avoid them.
Roofers are human lightning rods. Always Electricity causes muscles to contract. If
vacate the roof as soon as any lightning becomes evi- you’re holding on to a ladder and you hit an electri-
dent. Thunderstorms have a way of coming out of cal line with it, the electricity will cause your hand
nowhere, so this can be a real hazard, especially muscles to contract forcing you to remain holding
when aluminum ladders are being used, as alu- on to the ladder. If you have to touch a surface to see
minum is a great conductor of electricity. Don’t if it is conducting electricity (don’t try this), touch it
stand on the ground near a standing aluminum lad- with the back of your hand, then, if the surface is
der during an electrical storm, either. “hot” it will contract your muscles and throw your
Heat can be terrible on a slate roof during hand away from the surface. Better yet, if you have
the summer months. I have personally measured a any doubts about whether a metal surface on the
temperature of 1350 Fahrenheit on the working sur- outside of a house is “hot” or not (it happens), call
the electric company and let the experts take care of
it.
I have heard several accounts of people get-
ting electrocuted while working on construction
jobs. In one case, a man was carrying sheet metal
roofing up onto a barn roof, and the wind caught the
WEATHER HAZARDS ON SLATE ROOFS
metal and blew it against a high voltage line while
SLATE ROOFS ARE SLIPPERY WHEN WET!
the guy still had hold of it (he died instantly). One

The Slate Roof Bible — Chapter 11 — Safety 123

highly publicized case involved three men trying to der jacks and planks are available at almost any
take down a metal flag pole in the front yard of a lumber yard. The only specialty tool is the ridge
town hall. The pole hit a high voltage line and the hook, which is used to make a hook ladder (available
men stood in the yard in the center of town welded from several sources, including jenkinsslate.com).
to the flag pole literally frying to death in front of a In severe cases, a “harness” may be necessary, which
crowd of horrified onlookers for a full half hour is a safety belt that wraps around the worker and ties
until the electric company could shut off the power on to something to prevent a fall. In 35 years of
(the three men all died instantly). working at heights, I have had to wear a harness on
Interestingly, when I contacted my local only a few jobs, and I generally avoid anything with
electric company (West Penn Power) to get accurate ropes on a slate roof because ropes impede mobility
information on voltage levels of power lines, they and create a tripping and snagging hazard. People
routed my call to four different people (receptionist, who are not so accustomed to working at heights
engineer, public relations officer and safety manag- may want to use a harness more often. Some people
er) before finally stating that they wouldn’t give me use them all the time, and in some cases they’re
that information. They told me to look it up at the required by government safety codes.
library. So much for the “experts.” Go figure.
GROUND LADDERS
CO-WORKERS
A ground ladder is one that stands on the
Co-workers can be an unintentional hazard. ground and is used to get up to the roof. This is the
Like the uninformed wife who took off in the car typical ladder that most people are familiar with.
without first ensuring that her actions wouldn’t Aluminum ladders are recommended because
adversely affect her husband’s safety, co-workers they’re light in weight and easy to handle, although
cannot always be relied on to maintain safe working aluminum ladders do conduct electricity and are
conditions. As stated earlier, don’t rely on the judg- very dangerous around electrical wires. Ladders
ment of co-workers when your own safety is at stake. must be put up properly or they can be very haz-
Co-workers can drop things on you from above, ardous. Ladders will blow off the house if not tied
throw or drop things on the ground without looking, on, and are typically tied to a rain gutter, or a nail or
bump into you carelessly on the roof causing you to hook driven into the fascia. They must not be set up
lose your balance, knock you while carrying a ladder too steeply, or not steep enough (at too great an
on the roof, put up a ladder recklessly, attach a lad- angle), and must be put up plumb (perpendicular to
der hook to a ladder carelessly, install a roof bracket the force of gravity — not leaning sideways).
incorrectly, fail to tie ladders in place securely, over- Although smaller ladders can be put up by one per-
load roof scaffolds with too much weight, etc. This is son, longer ladders should be put up by two people,
not to suggest that co-workers are bad, but accidents for safety’s sake (see next chapter).
can and do happen, and you must keep an eye on
your co-workers when working at heights as if they HOOK LADDERS AND RIDGE HOOKS
were hazards themselves, because they can be.
Conversely, co-workers can greatly enhance your Once you get up to the eaves of a roof, you
safety, but accidents occur when people get tired, generally must use a hook ladder to get to the peak.
cranky, impatient, over-worked and careless. So con- Hook ladders enable the roofer to gain access to
sider this “a word to the wise.” most spots on a roof safely, without damaging the
slate. Don’t try to climb up a slate roof by walking on
3) USE THE PROPER EQUIPMENT the slate, hanging on a rope. Not only does this dam-
age the slate, but a loose slate can slip out when you
You can safely do almost any job on a slate step on it, and you will suddenly know what it’s like
roof with the following equipment: ground ladders, to ride a skateboard forty feet in the air.
roof ladders (also called hook ladders), roof jacks Good ladder hooks (ridge hooks) are inex-
(also called roof brackets), planks and ladder jacks pensive and will attach to almost any ladder.
(also called ladder brackets). Sources of tools and Typically, you would separate an aluminum exten-
equipment are listed in the next chapter and in the sion ladder into its two halves, then attach a hook to
back of this book, although ladders, roof jacks, lad- one of the halves in order to make a hook ladder. The

124 The Slate Roof Bible — Chapter 11 — Safety

ladder is simply slid up the roof until the hook drops pop up (the see-saw effect), the hook will disengage,
over the peak and secures itself. Usually, the hook is and you and your ladder will quickly plummet
facing upward when the ladder is slid up the roof, earthward. This is a very serious hazard when using
then the ladder is flipped over when the hook reach- hook ladders on old barn roofs, and you must be very
es the top. Better hooks have little wheels attached careful that the bottom of the hook ladder is lying tightly
to make it easier to roll them up the roof. against the roof when the top is firmly secured.
The hook ladder must be long enough to Otherwise, a block of some kind (a piece of 2x4 or
reach from the peak of the roof to the eaves in order 4x4) must be tied to the bottom and underneath the
to be able to climb onto it from the ground ladder. It hook ladder to prevent the seesaw effect from ruin-
is critically important that the ridge hook be secured ing your life. Also, a co-worker can sit on the top of
tightly to the hook ladder, as several contractors the hook ladder to make sure it doesn’t disengage.
have told me that their ridge hooks have come off at Hook ladders can also be hazardous when
the most inopportune of times. This is somewhat they have to be carried around on a roof, especially
surprising to me, as I have used hook ladders since long hook ladders. Typically, the hook ladder is car-
1968 and have never had a hook come off a ladder. ried along the ridge like a tight-rope walker carries
But then, I do keep a safe- his balancing pole along a tight-rope. This is the eas-
HOOK LADDERS ARE ty attitude, and check my iest way to move a ladder around on a roof, but it
SAFER THAN EITHER equipment regularly. requires a good bit of balance. However, a ladder will
ROPES OR “CHICKEN
A greater danger catch the wind much more readily than a pole will,
LADDERS”
when using hook ladders and a gust of wind can knock a person off balance
Swiveling angle-iron arises on old barns, and when carrying a hook ladder along a ridge.
end piece some old buildings. Such Alternatively, the person can sit on the ridge and
roofs tend to have a hump drag the hook ladder along the roof, but this actual-
in the middle, halfway ly requires a lot more effort (but little balance).
between the peak and Many contractors will use what are called
eaves. This causes the bot- “chicken ladders” instead of hook ladders. These are
tom of the hook ladder to home-made contraptions, usually made of wood,
be lifted off the roof sever- that function in the same manner as hook ladders.
al inches, and if you put They are not as safe or convenient as an aluminum
your weight on the bottom ladder with a ridge hook attached to it though, and
of the ladder, the top will therefore are not recommended.

Ladder hook (also called Gap under ladder

BARN ROOFS PRESENT A PAR-
ridge hook) shown attached (exaggerated)
to ladder. Hook ladders TICULAR HAZARD WHEN USING
allow for relatively safe HOOK LADDERS.
access to the top of roofs.
This type of hook is best
Old post-and-beam barn roofs
suited for slate roofs
will develop a hump across the
because it has a hinged,
middle, which will cause the
flat piece of metal contact-
bottom of the hook ladder to
ing the slate, which pre-
stick up in the air. When you put
vents breakage. This hook
your weight on the bottom of
is easily removable and
that ladder, the hook at the top BARN with gable roof
can be attached to any pair
pops up like a seesaw and dis- (not a gambrel roof)
of rungs on the ladder,
engages from the ridge, after
allowing for the working
which the ground begins to rise
length of the ladder to be
rapidly toward the roofer!
adjusted. The manufactur-
er of this hook specifies
that they be used in pairs
This is a common
(two hooks on the end of
type of hook ladder
a ladder instead of one),
not recommended
but two hooks on one lad-
for use on slate
der are sometimes heavy
roofs, because the
and hard to handle, thereby
hooks are pointed
posing a hazard them-
and will damage the
selves, and some roofers
slate.
use only one per ladder.

The Slate Roof Bible — Chapter 11 — Safety 125

 LADDER JACKS, ROOF JACKS slate roofs when two hook
AND PLANKS Old advertisement ladders are positioned on the
for roof jacks. roof next to each other, and a
Again, these tools are ladder jack is attached to
discussed in greater detail in each one, then one or more
the next chapter, but are men- planks are laid across the lad-
tioned here because you can- der jacks. This allows for a
not safely work on slate roofs, solid roof platform to be
at times, without them. Hook quickly and easily construct-
ladders only gain access to ed without the need to nail
roofs that have horizontal anything into the roof. This
ridges, which not all slate “roof scaffold” system is par-
roofs have. Some roofs come ticularly useful when working
to a point like a pyramid, on chimneys, as a hook ladder
some have flat tops, while others, such as gambrel can often be positioned on either side of the chim-
roofs, do have horizontal ridges but they can’t be ney, and planks can be run across from one ladder to
easily reached with a hook ladder. When you can’t the other just below the chimney in a very short
get a hook ladder up to a ridge, then you have to use period of time.
roof jacks and planks in order to get on the roof. Let’s take another look at the guy who tied
The terms roof jacks and ladder jacks are old- himself to his car and got yanked off the roof. He
fashioned roofers’ terms. Manufacturers call these obviously had a ground ladder or he wouldn’t have
things roof brackets and ladder brackets. They will been on his roof at all. If he had had a hook ladder
generally be referred to as roof and ladder jacks in he would have been able to climb onto his roof with-
this book for tradition’s sake. out the need for a rope. Two hook ladders would
Roof jacks usually nail to the surface of the have enabled him to get practically anywhere on his
roof, right through and on top of the slates, although the roof (one to go up and down from the ground ladder,
tongue can be slid underneath a slate before nailing and one to move around the roof by walking along
if necessary. They support horizontal planks which the ridge, which is the “sidewalk” on the roof). If he
are used as working platforms. A ladder can then be had the sort of roof where a hook ladder wouldn’t
carefully set on these planks and laid flat on the roof work, he could have nailed a pair of roof jacks to his
to get up higher. Roof jacks, when properly nailed in roof, working from his ground ladder, then laid a
place and used with a good quality, proper size plank across them and climbed onto this roof plat-
plank, are quite safe and indispensable for slate roof
work. They can be nailed into a slate roof and
Lightweight aluminum ladder jacks shown
removed from the roof without damaging the roof with and without scaffold planks
(this procedure is described in the next chapter).
A ladder jack does not attach to the roof, but
instead attaches to a ladder. They must be used in
pairs, much like roof jacks, and they have the same
purpose as roof jacks, namely to support planks so as
to provide a work platform. They come in handy on

Two hook ladders with ladder jacks are positioned on either side of
a chimney (left). 2”x10” planks are laid across both the ladders and
the jacks to make a safe and easily installed roof scaffold (right).
Double-wide planks can be laid on both the ladder and the jacks to
make a platform with greater capacity. If this scaffold is expected to
bear heavy loads, then use two ridge hooks per ladder. Access the
Roof jacks (also called roof brackets) come in several styles. other side of the chimney with a set of roof jacks and planks, or use
Some fold up and some are rigid. All are designed to hold planks. two more hook ladders with longer planks. Be careful not to over-
load the roof scaffold, as too much weight can mean disaster.

126 The Slate Roof Bible — Chapter 11 — Safety

form. He could then have set another ladder onto guardrail systems, safety net systems, or personal fall
this platform to get to the spot that needed fixed. If arrest systems.” For steep roofs, OSHA includes,
he still couldn’t reach the spot, he’d have to install “Each employee on a steep roof with unprotected sides
more roof jacks and planks until he got to where he and edges 6 feet (1.8m) or more above lower levels shall
wanted. Then if his wife got a sudden urge to run to be protected from falling by guardrail systems with toe-
the store, he’d survive unscathed. boards, safety net systems, or personal fall arrest systems.”
OSHA promulgates detailed regulations on every
OSHA aspect of construction workplace safety from the
type of extension cords that can be used, to fire pro-
The Occupational Safety and Health tection, sanitation, illumination, scaffolding, safety
Administration (OSHA) under the U.S. Department belts, ladders, tools, written safety records and just
of Labor, promulgates safety standards for the con- about anything else you can think of.
struction industry that apply to all employees and According to the National Roofing
subcontractors on any construction job. These regu- Contractors Association Safety Manual (2000), roof-
lations are detailed and extensive and require a ing slide guards (roof jacks and minimum 2”x6”
thick volume all to themselves. Persons subject to planks) can be used as alternative means of fall pro-
OSHA regulations should contact the U.S. tection on residential steep slope roofs, as long as the
Department of Labor and obtain a copy of the roof has an 8:12 slope or less and a rafter length of
OSHA regulations as they apply to the construction 25’ or less. Such slide guards must be installed along
industry. the entire length of the eaves and then every eight
OSHA regulations require that “no contractor feet up the roof. Roof brackets must be supplement-
or subcontractor shall require any laborer or mechanic... ed with guardrails and toeboards or with personal
to work in surroundings or under working conditions fall arrest systems.
which are unsanitary, hazardous, or dangerous to his
health or safety.” They further require that “each
employee on a walking/working surface with an unpro-
tected side or edge which is six feet (1.8m) or more above
a lower level shall be protected from falling by the use of

Nothing enhances the safety of working at heights quite like frame scaffolding, especially when securely tied to the building and otherwise used
properly — with safety rails, clamp-on platforms, self-leveling feet, and a hoist for lifting heavy material to the top. The author is shown, above
left, preparing to install new Vermont sea green slates on the Staples home in Sandy Lake, Pennsylvania. Brent Ulisky, the author’s step-son,
erected the scaffolding and is preparing to send up slates (above right). Photo at left by Brent Ulisky, at right by author.

The Slate Roof Bible — Chapter 11 — Safety 127

 Chapter Twelve

BASIC TOOLS AND EQUIPMENT

D
on’t read this chapter until you’ve from existing slate roofs when flashing metal is
read the previous Chapter Eleven on replaced, or when holes are cut into the roofs to
safety, which introduces you to some install (for example) skylights. The ripper is as
of the equipment required for slate work and important to the slater as the hammer is to the car-
explains some of the hazards one can, and will run penter.
into when working on slate roofs. This chapter will Although slate roofs are unique in many
show you how that equipment, as well as hand tools, ways, they have one particular quality that separates
are meant to be used. them from most other roofs: they can readily be
Slate work is a specialized endeavor requir- taken apart and put back together. A slate roof
ing some unusual tools and equipment not readily should be seen as an entity consisting of thousands
found at a hardware store. If you don’t use the right of parts, each removable and replaceable. Those
tools, you’ll have a very hard time doing any work on parts are the slates themselves, and they’re remov-
a slate roof. The tools you will need are available, able with the help of a slate ripper. Any individual
however, and it is strongly urged that if you intend slate can be removed from the field of the roof, and
to do any work on any slate roof, you invest in a few replaced, without hurting the roof in any way. This
tools appropriate for the job. Slate tools are not pro- is also done whenever flashing is being replaced, all
hibitively expensive and are well worth the invest- of which is routine when the proper tools are used.
ment. Like an automobile, slate roofs need to be
“tuned up” now and then. A car needs its spark
SLATE RIPPERS plugs replaced, while a slate roof needs a few slates
replaced occasionally. When you consider that an
There are several hand tools necessary for average slate roof may have 3,000 or more slates on
working on slate roofs, and the most important is the it, and that many slate roofs after a hundred years
slate ripper. The ripper is a long, sword-like steel have only had maybe 30 slates replaced, then you
tool that is inserted under a slate in order to hook can see that 99% of the roof has not needed repaired
the nails holding the slate and then pull or rip them in a century’s time. Nevertheless, many people will
out. They do not cut the nails as many people convince themselves that a 1% breakdown after a
believe, and they should not do so, as the remaining
cut-off nail shaft left underneath the slate creates an
irritating obstruction when trying to slide the new
slate into place. The nails should be completely
removed, and that is the job of the ripper, which is
inserted underneath the slate to be removed. The nail
shaft is hooked by the end of the ripper and the nail
is pulled out, usually bent in half, by vigorously
pounding on the ripper handle with a hammer.
Once both nails are pulled out, the slate can
be removed (some roof slates have more than two
nails). This procedure is necessary when replacing
slates, as the ripper enables the worker to remove the
old, broken slate, which must be done before a new
slate can be slid into place. Slates are also removed
A typical American slate ripper weighs about three pounds and is
about 30” long overall. The end with the hooks is inserted under
Opposite page: the slate to pull out (not cut) the nails. Sources of slate rippers
Old building in Angers, northwest France, displays include: Stortz; North American Bocker; AJC Hatchet Co.; ABC
the characteristic black slate of the region. Supply Co., Inc., and Jenkinsslate.com.
Photo by author.

The Slate Roof Bible — Chapter 12 — Tools 129

 out, and cut nails by both pushing and
pulling. It can be used to feel around
under slate to find obstructions, old
repairs, hidden nails under tarred slates,
etc. It even makes for a suitable bee swat-
ter in an emergency. It should never be
used to pry with, however, as it bends
easily and is not designed for prying.
Rippers are designed to pull out
roofing nails and not some of the larger
The diagram above shows the nails holding slate #1 in place (slates 2, 3 and 4 nails (such as 8 penny and 16 penny
are overlapping slate #1). In order to remove slate #1 from the roof, the two nails nails) that some roofers will incorrectly
must be pulled out, one at a time, with the ripper, as shown. The ripper is insert-
ed underneath the slate to be removed. A hammer is used to pound downward on
use to fasten replacement slates. A quick
the handle of the ripper in order to force the nails out, while the worker pulls on way to break a ripper is to hook it onto
the ripper with the other hand. Once the slate is out, a new slate can be installed an eight penny nail and try to pull it out
(see Chapter 17). Sometimes it is difficult to get the ripper under the slate and
hooked on the nail, because the slates are too “tight.” This problem can be allevi-
by beating on the tool. Broken rippers
ated by gently sliding a couple of nails under the bottom edge of the slate to can be welded back together, however,
wedge it up a bit (shown at right, above), and/or by pounding on the slate nail with and used again for quite some time.
the tip of the ripper before trying to remove it, as shown above, middle.
Sometimes a ripper will bend the
nail but not pull it out, and even though
century means it’s time to replace the roof. This is the old slate will come out, the old bent nail or piece
similar to saying that when the spark plugs of your of nail remains behind and blocks the replacement
car wear out, it’s time to replace the car! slate from sliding in. The solution is to use the rip-
The reason this may be hard to understand per to bend the nail back and forth until it breaks
is because slate roofs follow a time line that is not on off. That’s one reason the point of the ripper is
a human scale. Humans typically last maybe 80 indented — so nails can be pushed with the tool as
years, while slate roofs may last hundreds. So when well as pulled. Sometimes there is absolutely no way
people see an 80-year-old roof, they jump to the con- to get a ripper hooked on a nail, and then the nail
clusion that its time is up. This misperception is must be cut by using the point of the ripper and
compounded by the fact that America is a throw- pounding upward on the end of the handle. This is
away culture where people take for granted that only recommended as a last resort because you risk
when something breaks, it is simply thrown away pushing the nail up under the slate where it won’t
and replaced. Slate roofs, however, don’t break. Like come out at all (without removing more slates).
cars, they wear out, but unlike cars, it’s usually over Alternatively, when a nail nub is left under the slate
a period of time which may be centuries, depending because the ripper cut the nail rather than pulled it,
on the type of slate. And like cars, they can not only and the nub interferes with sliding the new slate into
be tuned up, but also completely overhauled. place, it is often easiest to simply remove more over-
A standard overhaul of a slate roof requires lying slates, expose the culprit, and pull it out or
replacement of such things as the metal flashings, pound it down with a hammer.
chimney tops, broken slates and possibly some roof The pointed end of the ripper can also make
sheathing (wood). A total and drastic overhaul may a suitable chisel for scraping old roofing cement off
involve removing the entire slate roof, replacing the the surface of a slate. Many tarred slates are cleaned
wood underneath, then re-nailing the same slate to up this way only to reveal that there was no reason
the new wood with new nails. At this point in time whatsoever for the slate to be tarred in the first place
(early 21st Century), many American slate roofs do — no hole, no crack, no exposed nail!
need overhauled somewhat if they’re going to last Hand tools can get very hot on slate roofs
another century. However, like a mechanic who can’t during the summer months, and rippers are particu-
get your spark plugs out without a spark plug larly notorious for this. They can actually get too hot
wrench, a slater can’t take your roof apart without a to handle, and gloves must be worn when using
slate ripper. them. When the ripper is not being used, the point
Like any craftperson’s tool, the ripper is a is slid far enough under a slate on the roof so that
tool that becomes more versatile as the user gains the ripper will remain safely lodged, out of the way,
more experience. It can pull nails out, push nails and easily accessible until it is needed.

130 The Slate Roof Bible — Chapter 12 — Tools

 SLATE CUTTERS

Contrary to popular opinion, roof slates are

not difficult to cut using a slate cutter, a simple hand
tool which is similar in principle to a paper cutter.
The slate cutter has a long arm with a cutting blade
on it; the slate is worked through the blade with one
hand while the cutting arm is operated with the
other. New slates, however, are quite a bit more dif-
ficult to cut than most old slates.
Slate roofing became an art long before elec-
tricity came into common usage, and usually no
electric tools are needed to work with roof slate.
Occasionally, a diamond blade cutter or a masonry
blade may be needed to cut very thick slates, or very
hard, new slates, especially when delicate cuts are
required. Generally speaking, though, standard
thickness (3/16” to 1/4”) roofing slates need nothing
but a hand-held manual slate cutter. The disadvan-
tage of using a diamond blade to cut slate is that the
saw cut leaves a square edge, whereas most roof
slates have beveled edges. The hand-held slate cut-
ters leave a beveled edge on the slate, matching the
original slate much better than a cut from an electric
saw. Also, electric cutters are much more dangerous
than manual ones, especially when used on the roof.
The best hand-held slate cutters can cut both
convex and concave curves in slate, and punch holes
in the slate, as well as make a simple, straight cut.
Many commercial slate cutters today don’t have hole
punches on them and can’t cut concave curves.
Concave curved cuts are necessary when the slater is
making a scalloped cut in a square slate to match the
scalloped design on an existing roof.
Old slate tools can occasionally be found at
flea markets, auctions, garage sales and antique
stores. Old tools can sometimes be superior to new
ones, and are often used by professional slaters. You
may still find an old Pearson cutter collecting dust
in someone’s basement or attic, as well as an old
Belden, Pecto or Red Devil ripper or slater’s ham-
mer, but not for long — these old tools are disap-
pearing fast.
A professional slater will carry a cutter with
him while on the roof, so it must not be a cumber-
some or awkward tool. Most cutters are designed so
they can be mounted on a board, which is fine when
using the cutter on a flat surface, such as on the
ground. But when up on a roof, a board is not neces-
sary, as the slate is being cut by a roofer usually
crouched in an awkward position, and the bottom
half of the cutter is simply tucked into the roofer’s
tool belt as the slate is cut. The cutter is then opened
The Slate Roof Bible — Chapter 12 — Tools 131
up and laid over the ridge of the roof for safe storage, page). Instead of a stake, though, almost any straight
or propped in a rung of a hook ladder until needed edge, such as the edge of a ladder or even another
again. slate, may do. Installation hammers also tend to be
Nifty little slate cutters are the “one-hand” lighter than the others — the amount of weight
cutters, which are small (about 10” long) and can be needed to pound slating nails is not great. Notable
carried in a tool belt. Made in France and Germany installation hammers include the German-made
and sold in the U.S. by Stortz and Bocker, they will Stortz hammer, the American-made Gilbert and
cut roof slate much as a pair of tin snips cuts sheet Becker hammer, the German-made Freund slating
metal. hammer, and a variety of other European brands.
Restoration hammers, on the other hand,
SLATE HAMMERS tend to be heavier hammers which are more useful
for beating on slate rippers, pounding larger nails,
A slate hammer is a unique tool that is very and doing the various demolition and reconstruc-
handy for a slater because it not only drives nails, tion tasks that restoration work dictates. Although
but also punches holes in slate. Traditional installa- these hammers do not include a slate-cutting shaft,
tion hammers are also used to cut slate. If you intend they do have a slate punch end which can also cut
to do any significant amount of work on slate roofs, slates in a pinch by perforating along a line, then
a slate hammer is an essential tool. breaking. Notable restoration hammers include the
Slate hammers generally fall into two loose American-made Estwing Latthammers and the
categories: installation hammers and restoration ham- German-made CK and Freund hammers. Europeans
mers. The installation hammers are distinguished refer to these hammers as “carpenters’ hammers,”
by their slate-cutting shafts. They’re available as but Americans tend to refer to them as “European
right-handed or left-handed hammers depending on roofing hammers.” An American carpenter wouldn’t
which side of the shaft the cutting edge is on. Some, be caught dead with a hammer designed to punch
such as the Gilbert and Becker slate hammer, have holes in roof slate, so the term “carpenters’ hammer”
cutting edges on both sides and are therefore suit- wouldn’t make sense in the U.S. In Europe, on the
able for either right-hand or left-hand use. This type other hand, slate roofs are so common that even car-
of slating hammer will cut slate on the job site by penters want their hammers to be able to punch a
chopping the roof slate while it’s laid over a slater’s hole in a roof slate.
stake. A stake is a T-shaped piece of iron that is driv- Few people realize that a hole can be
en into the ground or into a board or block of wood punched easily in roof slate by using a sharp object
and used as a back support for a piece of slate while — slates of standard thickness do not need to be
the slate hammer chops the slate to size (see next drilled. Traditionally, holes are punched in roof slate

SOURCES OF SLATE CUTTERS (see back of book)

Stortz; Evergreen; New England Slate; North American Bocker; ABC Supply Co., Inc.;
GT Products and Jenkinsslate.com.

ONE-HAND SLATE CUTTERS (right)

These devices are widely used in Europe where thinner roof slates are common.
Measuring about 10” long, these handy little cutters will go through a piece of stan-
dard thickness roof slate (3/16” or less), and still fit in a tool belt. The two on the right
have hole punches. French-made models sold by Stortz, German-made model sold
by Bocker.

132 The Slate Roof Bible — Chapter 12 — Tools

 Estwing Hammers: 34+ ounces
with a 21-ounce (600 gm) head
with cross-hatch face. Overall
length is a standard 13” (330mm).

805 grams (28.3

ounces), 12” long,
8.75” head

28.6 ounces
(811 grams),
12.5” long,
6.75” head

G&B Hammer:
11.5" long
overall; 9.5" AVAILABLE FROM
head; 852 LARIVIERE
WOOD HANDLE
grams total STORTZ
weight (30 (LEFT) AND
HAMMER: 7/8” STEEL HANDLE
ounces) Round strik- (RIGHT)
ing face;
Length of
head = 8.5”;
Length of
handle =
12.5”; Weight
= 25 ounces

The classic German-made Stortz slate hammer shown above is a “right-

handed” hammer. The cutting edge, on the right side of the shaft, as shown,
cuts roof slate with a chopping action when the slate is backed with a sup-
port, such as another slate, or a slater’s “stake” (see below). The pointed
end punches holes in slate. The handle is wrapped in leather. The leather-
handled Gilbert and Becker slate hammer is an American made classic with
a double-edged shank that can be used either right- or left-handed. Freund
and CK hammers, also German imports, include the European “roofing”
hammers (called “carpenter’s hammers” in Europe), which are ideal for
slate roof repair and restoration due to their heavier weight. Most of the top
row of hammers are heavier hammers having no slate-cutting shank (as the
ones below have), although all have a slate punch. The heavier hammers
are more suitable for beating on a slate ripper (for example) than are the
lighter slate installation hammers. The American-made Estwing hammers,
like some of the Freund and CK hammers, are called carpenter’s hammers
in Europe, but are slate roof restoration hammers in the U.S.

SOURCES OF SLATE HAMMERS (see rear of book): John Stortz and

Son; North American Bocker; Carl Kammerling and Co.; ABC Supply Co., Slater’s Stake (approx. 20” long) — to support a roofing
Inc., GT Products and Jenkinsslate.com. slate while being trimmed with a slate hammer.

The Slate Roof Bible — Chapter 12 — Tools 133

using any slate hammer, all of which have sharp mers without cutting shanks can be used to cut
points for that purpose. If the hammer doesn’t have slates. Also, this slate-cutting technique can be per-
a slate punch on it, it’s not a slate hammer. formed with any hammer and a nail, so that even the
A crude way to cut slate is to use the pointed average do-it-your-selfer can cut roof slate without
end of a slate hammer (or a hammer and nail) and special tools.
perforate holes along a line on the slate, then break
the slate on the dotted line. Once the slate is cut, the MISCELLANEOUS HAND TOOLS
jagged edge is tapped straight-on with the hammer
to remove the roughness. In this manner, even ham- Other hand tools commonly required for
work on slate roofs and frequently carried in a
slater’s tool belt are tin snips (aviation snips) for cut-
ting flashing and sheet metal; utility knife for gener-
al purposes; tape measure (25’ length); chalk line
(for chalking lines when installing new roofs or val-
leys); utility pencil (carpenter’s pencil or other
marker); flat pry bar (also called “wonderbar”), for
removing face-nails, prying up slates, removing
ridge iron and flashings, scraping tar off roofs, etc.;
hand tongs for bending sheet metal; thin chisel for
flashing work; and a nail punch, such as a 1/2” bolt
about 4” long, for setting the nail when replacing a
slate, and for punching nails down through the slate.
An additional set of tools is required for
masonry work on chimneys, and that is discussed in
Chapter 19.

GROUND LADDERS

Not much work would be done on slate roofs

without ground ladders — they’re critically impor-
tant pieces of equipment that have a degree of versa-
s John Stortz and Son, Inc., Philadelphia, have provided for over 150 tility to them and, with experience, can be used to
years some of the highest quality slate roofing tools found anywhere.
Their standard (USA) ripper is widely considered the best available
gain access to even the most unlikely places. The
on the market and indispensable to the slate roofing trade. Above, recommended type of ladder is either a medium or
John C. Stortz puts the finishing touches on one of the rippers. Stortz heavy duty commercial aluminum ladder. Be sure to
also manufactures/distributes slate hammers, cutters, stakes, tongs
and many other tools for roofing and masonry applications. Photo by author. read the section pertaining to ladders in the safety
chapter first, and don’t electrocute yourself when
putting up or taking down an aluminum ladder.
The first task when using a ladder is putting
it up. This can be done by one person by simply
lodging the base of the ladder against a solid object
such as the side of a house, and “walking” the ladder
up. To walk the ladder up, simply start at the top of
the ladder, hoist it overhead at arms length, and start
walking toward the stabilized base of the ladder,
moving your hands forward rung to rung until the
ladder is standing straight up. Then pull the base of
the ladder back away from the building so the ladder
is standing vertical, extend the fly until it reaches
the eaves, and lean it against the building. If you’re
A variety of miscellaneous tools and materials can come in handy
when working on slate roofs. All are available at
walking up an extension ladder, do not extend the
slateroofcentral.com (ph: 814-786-9085). ladder before walking it up; instead, extend it after it
has been stood up in a vertical position (this may
134 The Slate Roof Bible — Chapter 12 — Tools
take some practice for the inexperienced person). quick anchor to tie to when nothing else is available.
The ladder is taken down in the same manner — the Many aluminum ladders come equipped
extension is retracted, the base is wedged against with an attached rope meant to be used to extend the
something solid and stationary, and the ladder is ladder. Some people swear by this rope, others take
walked down backwards. the rope off right away and never use it at all.
Once a ladder is standing vertically and not Originally, extension ladders were made of wood
leaning on something, it’s very unstable unless it’s and were quite heavy, and ropes weren’t sufficient to
kept perfectly plumb (straight up and down). So it’s extend them, so many older roofers developed the
extremely important to hold the ladder plumb when habit of extending the ladder by climbing up the
moving it around, such as alongside the house. rungs and pushing the “fly” ahead of themselves.
Better to leave the top of the ladder leaning slightly This requires two people when a ladder is long or
against the building when moving it along, if possi- must be extended very far, but can easily be done by
ble. one person in most situations.
It’s easier to handle a ladder with two peo- Any time a ladder is stood up vertically and
ple. To put up a ladder with two people, one keeps a the base placed in its permanent location, the ladder
foot on the base of the ladder while the other walks will not stand plumb if the ground on which it is
it up. The ladder is turned on edge during this pro- standing is not level. Before the ladder is leaned
cedure to make it easier to keep a foot on the ladder. against the building, it must be plumb in order for it
The foot must not be taken off the ladder until the to be safe, otherwise it may slide in one direction or
ladder is vertical, otherwise the base will fly up, the another along the eaves or along the rain spouting,
top of the ladder will plummet to the ground, and causing the ladder climber to lose balance. To check
loud, unpleasant noises will come from the guy who whether a ladder that is already leaning against a
was trying to walk it up. building is plumb, stand on the bottom rung and
Once the ladder is up in a vertical position, pull the top of the ladder away from the building
one person stands behind the ladder (between the slightly. A plumb ladder will drop right back against
ladder and the building) and supports it with two the building in the original place. The top of an
hands, while the other extends the fly (moveable) incorrectly erected ladder will move to one side or
section of the ladder, even climbing the ladder if another. It’s always wise to make certain a ladder is
necessary. The person supporting the ladder must be plumb before you climb it, especially if someone else
strong enough to hold it nearly plumb, but leaning a put it up. You don’t want to get to the top and real-
little toward the house so it doesn’t fall backward or ize the ladder hasn’t been put up properly and the
sideways with the other person on it. top is now sliding sideways, with you on it!
If a person is putting a ladder up alone and To make the ladder plumb on an uneven sur-
must extend the fly, the ladder is held plumb with face, don’t prop one of the legs on top of something if
one hand, a foot solidly holds down the bottom rung you can avoid doing so. Instead, dig a hole and drop
of the ladder, and the other hand extends the fly the other leg into it. It is much more stable and safer to
either by pushing on it, or by pulling on the ladder dig a hole for one ladder foot than to prop the other foot
rope, until the fly reaches the eaves of the building, on something. A hole can be dug quickly in soil with
if possible. Then the person can climb the ladder the claw end of a claw hammer, and easily restored
and extend the fly to the desired height by pushing after the ladder is moved. This can’t be done, of
the fly upward as the ladder is climbed, being care- course, when on pavement, or setting a ladder up on
ful that the ladder is leaning against the building a roof (porch roof for example), and in these cases a
with enough slope to keep it from falling backward. prop must be used to level the ladder’s feet. A solid
Once the ladder has been extended, the base can be plank with one end propped on a block of some sort
moved back from the building to its proper final dis- usually does the trick.
tance, which should leave a slope on the ladder that Most ladders have feet that swivel backward
is not too steep or too shallow. or forward. These come in handy for leveling the
The ladder top should always be tied to the base of the ladder when the surface is just slightly
building after the ladder has been erected. Rain out of level. Many ladders can be lowered slightly on
spouting often comes in handy as a place to tie on to, one side if the foot on that side is swiveled backward,
but when no rain spouting is available, something and can be raised slightly if the foot is swiveled for-
else must be used. A 16-penny nail driven solidly ward. Some ladders do just the opposite, so you’ll
into the fascia and bent into a hook will make a have to experiment with yours. It’s routine to climb

The Slate Roof Bible — Chapter 12 — Tools 135

Ladders have a top and a ladder when its feet are bent already attached to it. Instead, you buy the hook sep-
a bottom. The bottom
has the feet. The move- (swiveled) backward or forward. arately and attach it to one of your own aluminum
able part of the ladder The more extended the lad- ladders. Hook ladders are discussed in the previous
is called the “fly.” der is the more top-heavy it will chapter, and if you haven’t read about them there
be, and the less stable it will be already, now is a good time to do so.
when trying to move it. The rule Hook ladders enable a roofer to climb on
of thumb is to retract the fly before slate roofs without putting weight on the slate itself,
moving a ladder, then extend it thereby preventing damage to the slate. They also
again when the ladder is where keep the roofer off the slate when the roof is too hot
you want it. The other rule of to touch, preventing the roofer from becoming roof-
thumb when moving a ladder is to burned (it happens). Never use ropes to climb on slate
keep it as plumb as possible when roofs because they force you to walk on the slates,
moving it. Often it’s best to walk which are subject to breakage under the weight of a
the ladder down, move it, and person’s feet. Slate roofs are not sidewalks and
walk it back up. should not be walked on unless absolutely necessary.
Most of the work commonly One of the main reasons slate roofs go bad on porch-
done on slate roofs is done on es and other low-slope roofs is because people tend
hook ladders (roof ladders), not to walk on them. Generally speaking, the steeper
on ground ladders, unless work- and higher a roof, the better condition it will stay in,
ing along the eaves or drip edge since people stay off steep roofs. In addition to
of a roof. If both hands are ropes, home-made chicken ladders (wooden hook
required when working at the ladders) don’t make any sense when steel ladder
top of a ground ladder, then one hooks are so inexpensive and relatively safe.
of the worker’s legs should be A good ladder hook has a flat, swiveling
wrapped around a pair of ladder piece of angle iron on the end which prevents the
rungs as shown in the illustra- slate from breaking under the pressure of the hook.
tion on the following page. It should also be easy to clamp onto a ladder.
A good all-around ladder for Although the hook is typically attached to the top
working on a two-story house is two rungs of the hook ladder, it can be attached to
a 32-foot, medium duty com- any pair of rungs lower down on the ladder in situa-
mercial ladder. A 40-foot ladder tions where the available hook ladder is too long to
is necessary for higher homes, be practical.
but a 32-foot ladder will easily The better ladder hooks have a rolling wheel
reach well beyond the eaves of that enables the hook ladder to be rolled up the roof.
most homes, and it’s a relatively A rolling hook should have a wheel that only rolls in
easy ladder to handle, especial- one direction (up and down the roof), and not side-
MAKING A GROUND
LADDER PLUMB VERTICAL
ly for one person. ways. So if you have a hook with a swivel wheel on it,
you should take the wheel off before an accident
Moving a ladder foot happens.
backward or forward will
HOOK LADDERS
drop or raise that foot It should be noted that the manufacturers of
slightly thereby helping A hook ladder is any ladder some ladder hooks specify that two hooks be used at
to plumb the ladder. the same time, side by side, on the same rungs of
that has a ridge hook attached
to the end, so the ladder can be each hook ladder. If you do any amount of slate
hooked over the ridge of a roof. work, however, you’ll soon learn that a hook ladder
Hook ladders are one of the with two steel hooks is very top-heavy and hard to
most important pieces of equip- handle and therefore a hazard of its own. Two hooks
ment for anyone wanting to are likely to be required, however, when a heavy
work on a slate roof. They make weight will be loaded on the ladder hooks, such as a
a difficult and dangerous job roof scaffold holding masonry materials.
relatively safe and easy, and The disadvantage of a hook that can be fas-
they’re not hard to come by tened on and taken off the ladder easily is that the
because you don’t have to buy a hook may come off when you don’t want it to, like
special ladder with a hook when you’re sliding the ladder up the roof to hook it

136 The Slate Roof Bible — Chapter 12 — Tools

 It is much easier for two people to put up a long or heavy
ladder than one person alone. The fellow on the left
keeps his foot planted firmly on the ladder until it is
walked up all the way by the other fellow. He also pulls
on the ladder to help lift it as the other fellow walks it up.
The ladder is turned on edge to allow for a secure place
to set one’s foot. The procedure in reverse will safely
bring a ladder down.
Always watch for electrical wires when putting up
or taking down a ladder!

on the ridge. The author has never had

this happen, but other contractors
have had their hooks fall off. The
solution to this potential problem is
to always make sure the hook is
attached square, snug and centered
on the rungs of the ladder and the
wing nut is firmly secured. Obviously,
if you put the hook on the ladder
hastily, you’re asking for trouble. The
top edges of ladder rungs are slanted
in one direction so as to allow for a
level surface to stand on when the lad-
der is angled against a building.
Hooks are designed to clamp onto those rungs and hook facing up, until the top of the hook ladder
are made to accommodate that slant, so they can be reaches the peak. The hook ladder is then flipped
put on backwards by someone who’s not paying over and hooked on the ridge. The reverse procedure
attention, and if so, they won’t attach firmly. When will get the hook ladder down. If the hook ladder
you’re standing on a hook ladder on a high roof, the needs to be moved sideways one way or the other, it
hook itself is the only thing protecting you from the can be “rolled” from the ground ladder (turned on
force of gravity, a force to be reckoned with when its back, then onto its front in a rolling motion).
working on steep slopes. That hook should be high- It takes some practice to get hook ladders up
ly respected and used properly, with utmost care. and down safely, and it can be a dangerous job, espe-
There are other styles of ladder hooks, such cially on high, steep roofs requiring long hook lad-
as pointed ones that are used in pairs and attach to ders, or on windy days. Perhaps the most important
the side rails of the ladder; these are used by people trick in carrying hook ladders up to and down from
who only need to get up and down the roof (such as roofs is to learn where the center of balance of the
firemen) and don’t need to actually work on the roof hook ladder is (hook ladders are top-heavy because
itself. They are of no use to slate roofers. of the hook). Grab the ladder just above its center of
In order to get a hook ladder up onto a roof, balance when carrying it up or down a ground lad-
first the ground ladder must be set up properly. der. It will then tilt over the eaves and lie on (or
Then the hook ladder is “walked” up (often by prop- come off) the roof easily. Make sure your body’s
ping it against the base of the ground ladder) and chest level is just above the pivot point at the eaves
leaned against the ground ladder, leaving enough of the roof when you tip the hook ladder on or off the
room beside it to allow the worker to climb the roof. Once again, remember the rules of safety, and
ground ladder. The ground ladder is then climbed if it doesn’t feel safe to you, don’t do it — you can
until the climber reaches about 3/4 of the way up the always practice with a shorter, lighter ladder first.
hook ladder. The worker then holds the hook ladder A professional slater will often use several
against his shoulder while grasping one of its rungs hook ladders at the same time on a roof. One may be
tightly, and climbs up to the top of the ground lad- used just to get up and down from the ground ladder
der carrying the hook ladder. At the top, the hook to the roof peak, while another may be used to work
ladder is raised up far enough to tilt over the edge of the other side of the roof. Smaller hook ladders may
the eaves and lay on the roof, after which it is care- be used to get around chimneys or to work on
fully (so as not to damage slate) slid up the roof, dormer roofs, and often hook ladders will be paired
The Slate Roof Bible — Chapter 12 — Tools 137
to make a roof scaffold around a chimney. So it’s need to be drilled). This is especially true of older
always a good idea to have more than one hook slates, although some of the very hard slates, such as
handy, and more than one hook ladder available. the New York red slates or Peach Bottom slates, may
Fortunately, any extension ladder can be taken apart tend to crack when nailed through even after a cen-
and one half (or both) put to use as a hook ladder, tury of age, and may require drilling first with a
then the extension ladder can be put back together masonry bit. For the most part, though, a nail can be
when the hook ladder is no longer needed. This is driven through an old slate roof with impunity.
one reason to remove ropes from ladders when not Alternatively, a slate can be removed using a slate
needed — then the ladder can be taken apart and ripper and the roof jack can then be nailed to the
put back together more easily. roof without damaging any slates. The removed slate
is later replaced using a slate hook.
ROOF JACKS (BRACKETS) Roof jacks will always have at least three
holes through which to nail them. Many have two
Roof jacks are important tools for any roofer, sets of three holes. There is a good reason to have
especially slate roofers. Also called roof brackets, three holes on a roof jack — that’s how many you
they’re used to support planks on the roof and there- should use when safely attaching the jack to the roof.
by create roof scaffolds, which allow a safe place to One nail is not enough, two may do, but three is the
stand or to set another ladder on the roof surface. It’s right number. When nailing a roof jack to a roof
very important to know how to attach roof jacks to a always use three nail holes or slots and make sure all
slate roof safely without damaging the roof, as roof three nails hit something solid. If you’re not hitting
scaffolds will make many a seemingly impossible something solid with your nails, move the roof jack
roof job vastly easier and safer. Speaking of safety, and try again (and be sure to cover your old nail
roof jacks are discussed in the previous chapter, and holes with flashing slid under the slate, if you punc-
that information should be reviewed before attempt- tured the roof!).
ing to use roof jacks. Furthermore, on steep roofs use 16d com-
Many roof jacks fold up for storage, and this mon nails (3.5” long) when nailing roof jacks
can be a hazard when the jacks have not been cor- through the slate. When doing so, it’s critically
rectly latched open before being nailed on a roof. important to make sure the nail heads have properly
You don’t want to get up on a roof scaffold and have hooked the roof jack, and aren’t driven in so far that
it suddenly collapse because a roof jack wasn’t the roof jack has nothing to hold on to (it’s the nail
locked open. Always check them before putting your heads that keep the jack from sliding off the roof, so
weight on them, or else use fixed (non-collapsible) use stout nails with good, large heads). When nail-
jacks. ing jacks to a felted roof deck when no slate is pres-
Roof jacks are typically nailed on top of the ent, standard 1.5” roofing nails will usually suffice.
slate roof, in the slots between the slates where the
slates abut one another side to side, and are nailed
VERSATILITY OF HOOK LADDERS
through the underlying slate. In the same way that a
hammer and a nail can be used to punch a hole in a The longer hook ladder in this illustration is slightly angled across
the roof, which is often necessary to gain access to difficult areas.
slate, a nail can usually be driven through a slate The shorter hook ladder has the hook attached two rungs down
without cracking it (new slates or thicker slates may from the top to shorten the working length of the hook ladder in
order to access a section of roof that would otherwise be difficult
to reach. The hook ladder can be angled across the roof only
when the ladder hook has a swiveling piece of angle-iron on the
end that contacts the roof.

SOURCES (see back of book): Jenkinsslate.com; Fulton

Corporation; Acro Building Systems, Inc.; Reimann & Georger.

138 The Slate Roof Bible — Chapter 12 — Tools

 The jacks themselves only hook onto the jacks are sufficient for a plank that’s eight feet long,
nails, and they’re readily removable with an upward although three roof jacks over a span of eight feet are
tap of the hammer on the bottom of the jack, much safer when a lot of weight is involved. If you
although removing the nails is often another matter doubt the strength of your roof scaffold, you can
altogether. The nails must be removed from the slate always add a central roof jack to beef it up.
roof or else covered with hidden flashing after the Other types of scaffolding are also useful
work is done. Sometimes 16 penny nails can be pried when doing work on slate roofs, and these include
from the roof with a hammer using a slate ripper or ground scaffolding (pipe or frame scaffolding)
the jack itself as a backing to prevent the pressure of which sits on the ground and stacks one stage on top
the hammer head from breaking the slate. If this of another; pump jacks, which attach to vertical
won’t work, then the nails are simply driven into the 4x4’s; and planks (either wood or aluminum) that sit
roof using a nail punch (a 1/2” x 4” bolt will do fine), on ladder jacks positioned on ground ladders below
and left there. the eaves of a building. Ground scaffoldings usually
After removing the roof jack, you’ll have won’t be required when doing general slate restora-
three nail heads or nail holes (depending on whether tion work, although they can come in handy at
you pulled the nails out or drove them in) situated times. Frame scaffolding especially can greatly
in a slot on the roof between two slates, and these enhance the safety of high jobs, as well as new instal-
will leak. This is not a problem, however, as a piece lations, eave and gutter work. Frame scaffolding can
of metal flashing called a bib is simply slid under the readily be rented, and the rental agencies will often
slot and over the holes to leave the area leak-proof. erect the scaffold for an extra fee.
The metal should be non-corrosive (copper is ideal, When using frame scaffolding, always tie the
but aluminum, especially brown-painted aluminum, frames to the building every three stages of height,
works well too), and should be bent lengthwise minimum. If the building is masonry, drill holes
slightly so as to be force-fit under the slate, thereby into the mortar joints and slip in lead sleeves, then
preventing it from sliding back out. A lengthwise screw sturdy eye-hooks into the sleeves to tie to.
bend in the middle of the metal not only wedges the These hooks will be readily removable when the
metal in place, but helps the metal ride over the nail scaffold comes down. Always use a complete set of
heads, if there are any. The insertion of this metal safety rails at the top of the scaffold, which includes
flashing is almost always assisted by a slate ripper, vertical posts and a double set of horizontal rails. To
which pushes the flashing into place. make it easier to get materials up to the top of the
The metal flashing should be at least 4” scaffold, a well-wheel and pulley system made
wide and long enough to cover the nail holes with at specifically for the scaffold will be necessary.
least an inch or two of overlap on the bottom, and 2” Otherwise, a much more expensive electric ladder
of underlap under the next course of slates above. A hoist system works well, too. And finally, always (in
length of 7” works well on many roofs, although my opinion) use aluminum planks at the top of the
sometimes longer and wider bib flashing is required. scaffold, the kind that are made specifically for the
Don’t use shiny flashing or white flashing, as it looks scaffold and that hook safely into place. Do not use
unsightly in the cracks between the slates. Using the wood planks. Aluminum scaffold platforms are not
above technique, roof jacks can be safely attached to that expensive and safety should never be compro-
and removed from slate roofs without creating leaks. mised to save a buck. Wood planks may be cheap,
but they’re narrow, can slip or break, and just aren’t
SCAFFOLDS worth it. You can always tell a good contractor or
craftsman by the condition of his or her equipment.
Roof scaffolds are either typically made with Wood planks on scaffold frames are sub-standard
roof jacks and planks, as already mentioned, or with and should be avoided. I guarantee that when you
ladder jacks (on hook ladders) with planks. Planks read about people dying from falls from scaffolding
can be either wood or aluminum. The roof scaffold (and you will), it’s because they did not use proper
is only as good as its weakest part — even if roof aluminum scaffold planks, proper safety rails, or
jacks are nailed in place with three 16 penny nails proper tie-off procedures.
each, and (if collapsible) firmly latched open, a bad Furthermore, pipe scaffold must be set up
plank will make the scaffold unsafe. A 2”x10” plank exactly plumb. Adjustable screw feet make this job
free of large knots, splits, checks or other flaws infinitely easier. Do not pile blocks up on the
makes a good scaffold plank. Typically, two roof ground to try to create a level surface and then set
The Slate Roof Bible — Chapter 12 — Tools 139
 ATTACHING ROOF JACKS TO A SLATE ROOF your scaffold on top of them; if you don’t have screw
feet, then buy some. Finally, avoid electrical wires
On standard thickness (3/16” to 1/4”) slate roofs, the roof (and lightning) when using metal scaffolding.
jacks can be nailed on TOP of the slates in a slot between
the slates. On thicker slates such as on the bottom of a
graduated roof, the roof jacks should be nailed in the same SLATE HOOKS
position but UNDERNEATH the top slate. In both cases,
the nails penetrate the slate through the overlying slot. Use Slate hooks are widely used by slate roofers
three 16 penny common nails, making sure they all hit to attach replacement slates, instead of using the
something solid. To remove, knock off the bracket, then pry
out the nails using the bracket as a backing to prevent
nail and bib flashing technique discussed in the
breaking the slate, or pound the nails down into the roof Chapter 17, and no list of slate equipment would be
using a hammer and a bolt. Install a copper or brown-alu- complete without the slate hook. The slate hook is a
minum bib flashing under the slate, but over the holes. simple copper, galvanized, or stainless steel hook
that is nailed into the roof after a bad slate has been
Alternatively, first remove the slate where the roof jack is to
be nailed, then nail the jack directly to the roof sheathing in removed. The new slate is slid into place and the
the space between the underlying slates. When done, hook keeps it from sliding back out. Copper hooks
remove the jack and replace the slate (this is the most can be difficult to use on roofs that have hardwood
common roof jack installation procedure on ceramic tile sheathing because they may bend when you try to
roofs).
nail them into place. Galvanized slate hooks will
16d nails rust in time and leach rust stains onto the slate roof.
Stainless steel slate hooks are recommended.

NAILS

The common nails for nailing standard

thickness (3/16”) slate are 1½-inch-long, 11 gauge
copper roofing nails (see Chapter 13). One way to
calculate nail length is by using the following for-
On standard thickness slates (3/16”- Slide roof jack underneath very
1/4”), nail roof jacks on top of the thick slates if nailing on top of mula: nail length = thickness of slate X2 plus one
slates through slot between the slates. slates. Otherwise, remove the inch. For a standard quarter inch slate, the nail
Alternatively, remove a slate and nail top slate and nail the jack to the
the roof jack to the roof in the space roof deck between the underly- length, then, would be 1.5 inches.
between the underlying slates. ing slates.
Although copper roofing nails are the pre-
After removing the roof jack, slide a piece of non-shiny metal “bib”
ferred nails specified by professionals, 99% of old
flashing under the slate to cover the holes, (or nail heads) as shown. slate roofs do not have copper nails — they have hot-
Use the point of a slate ripper to push the metal under the slate. dipped galvanized nails, or even cut steel nails, both
Bend the metal lengthwise to make it easier to ride over the nail
heads, and to force-fit the metal so it won’t slide back out. Use cop- of which are far less expensive than copper and will
per or brown-painted aluminum flashing so the metal won’t rust. usually last at least a century. In fact, many century-
old nails of these types are in good enough condition
to be used over again. So even though industry pro-
fessionals insist on using copper nails, if you’re
using a good, hot-dipped galvanized nail to fasten the
slates to a roof (especially salvaged slates), you’ll
find that they work quite well. Copper nails, howev-
er, are superior to hot-dipped galvanized, and stain-
less steel are superior to copper, so these are the
nails to use when installing new slate. Aluminum
nails should be avoided as they don’t last long
enough on a roof. Longer and heavier copper nails
are required for thicker slates or for nailing copper
ridges, ceramic tiles, etc.
Never use electroplated galvanized nails,
which are cheap nails made for asphalt shingles, and
should not be used on a slate roof. Electroplated
nails are marked “EG” roofing nails (electro-galva-
140 The Slate Roof Bible — Chapter 12 — Tools
nized), whereas hot-dipped nails are clearly marked 1) Roof cement should never be visible
“hot-dipped.” on the surface of a slate roof. This
The traditional nail for fastening galvanized goes for both installations and for
(“tin”) ridge iron to a slate roof is the eight penny (2 repair work. Granted, there is one
1/2” long) hot-dipped galvanized nail. After this nail type of slate ridge installation
is pounded into place, the head is covered with a dab which requires exposed nail heads
of caulk (lifetime durability clear silicon is recom- (an installation procedure that I do
mended). Some roofers insist on using gasketed not recommend, shown on the
nails on ridge iron, but a standard eight penny nail Smithsonian, p. 27), but these nail
with a caulked head works best. Copper ridge, of heads can be caulked with lifetime
course, requires copper nails. When nailing copper silicon caulk rather than the more
flashings, valleys or ridges, one should always use unsightly roof cement. 2) Roof
copper or brass nails to prevent galvanic action. cement should not be routinely used
Galvanic action occurs when dissimilar metals are underneath slates during installation
placed in contact with each other, leading to the as is sometimes recommended by
deterioration of the electropositive metal. This is printed installation directions. The
discussed further in the Chapter 18. incorrect practice of cementing
Stainless steel roofing nails should be con- eave, valley and ridge slates into Available from:
sidered whenever installing a new slate roof onto place was, unfortunately, pub- Jenkinsslate.com
and from slate
old, hard roof sheathing. Southern yellow pine or lished as an accepted procedure in suppliers (see
northern hardwoods, although they can last for cen- the 1926 book, Slate Roofs, now back of book)
turies on a roof, become quite hard when dry and extensively reprinted and therefore
may bend copper roofing nails. Switch to stainless perpetuating an un-ending plague to those of us who
steel roofing nails to solve this problem. actually have to repair or maintain slate roofs.
Fortunately, most slaters of old either never saw that
ROOF CEMENT AND CAULK book or else had sense enough to know not to cement
the slates into place, as 99.9% of all old slate roofs
Remember these two rules about roof were not installed in this manner. Slate roofs are
cement, also known as “mastic,” or “tar” — a black, ingenious roofing systems because they can be taken
plastic material that is either trowel or brush grade: apart and put back together, but not when they have

USING ROOF JACKS

The technique shown below can be used to repair most WITHOUT NAILING THROUGH SLATES
holes in slate roofs. If a slate has a hole in it, slide a piece
of metal under the slate, do not put tar on top of it. 1) Remove a slate by pulling it out with a ripper. Nail a roof jack
into place by nailing directly into the roof deck in the slot
between the slates underneath.
2) Stage the roof with adequate roof scaffolding.
3) When done, remove the roof jack by knocking it off the nails
and then either pry the nails out or punch them down. Then,
install a stainless steel slate hook where the slate is missing and
hook a slate in place. The slate can always be removed again
later should the unlikely need for future roof scaffolding present
itself.

The Slate Roof Bible — Chapter 12 — Tools 141

been cemented into place! Slates are best installed with such as during a rainstorm, and it’s a good idea to
nails, and no roof cement is needed. The only excep- keep some handy if you’re a roofer, although stan-
tion to this rule is when small pieces of slate are dard roof cement has more body and is the preferred
being installed in an unusual circumstance, such as material for general roof repairs. Roof cement is also
on a steep hip or small finial, or when edge slates are available in caulking tubes.
exposed to abnormally high winds and likely to be A good all-around caulk for slate roofs is
blown off — then some cement or caulk under the clear, lifetime silicon caulk. It really sticks to just
slates is recommended. about anything, holds tightly, lasts a long time, and
Roof cement comes in two standard vari- is waterproof immediately (although it can’t be used
eties: standard or “wet surface.” Wet surface roof on damp surfaces). It’s used to seal exposed nail
cement can be used to seal leaks on damp surfaces, heads, to glue small pieces of slate into place when
necessary, and to fill mortar joints on chimneys after
they’ve been reflashed.

LADDER JACKS AND STAND-OFFS

Ladder jacks (also called ladder brackets)

are used to support planks and create working plat-
forms on ground ladders or on hook ladders. There
are many different types of ladder jacks, and they’re
most often used often by contractors who attach
them to ground ladders for the purpose of working
on the siding, gutters, soffit, fascia or eaves of a
house. Ladder jacks are most useful to slaters when
attached to hook ladders to create a quick and stur-
dy roof scaffold without nailing anything into the
roof. As such, the best ladder jacks to use are light-
weight, aluminum ladder jacks, which can be car-
ried up and down a ladder with ease. They require
no tools to attach to the ladder, and simply clamp
onto the ladder by design. They must be used in
pairs, and therefore require pairs of hook ladders.
They’re especially handy when working on chim-
neys. Hook ladders must be heavy duty if the roof
scaffold attached to them is going to support heavy
weight, such as bricks.
Planks are laid across the ladder jacks in
order to create a work platform. Aluminum planks
span longer distances and can be much safer than
wooden planks when the ladder jacks are attached to
Pipe scaffolding provides additional safety
when working on high roofs. ground ladders, especially as aluminum planks can
Photo by author.
be clamped to the ladder jacks and can be used with
safety rails.
Stand-offs are aluminum devices that clamp
to the top of the ladder and hold it away from the
building or roof. They enable one to work on, for
example, the gutters or drip edge of the roof without
the ladder having to lean against the work area. Both
aluminum ladder jacks and stand-offs are available
at most building supply stores.
Ladder jacks and planks on hookladders make a quick and safe
roof platform for easy access to a chimney or other roof protrusion.

142 The Slate Roof Bible — Chapter 12 — Tools

 Chapter Thirteen

INSTALLING SLATE ROOFS

A
slate roof is a perfect roof. It’s beau- tionally nailed onto solid wood roof decks built of
tiful, natural, durable, recyclable, natural boards. This traditional style of construction
environmentally friendly, easy to has been tried and proven over centuries and can
maintain and costs less than just about any other easily be duplicated when installing slate roofs on
serious roof when the life of the roof is taken into new or restored construction today. The primary
consideration. Although there are many myths and characteristics of traditional American slate roof
misconceptions about installing slate roofs, there’s construction are as follows:
really nothing mysterious about building a roof of 1) The slates are nailed, not hooked, onto a
stone. The stone is dug or quarried from the earth, completely sheathed roof deck rather than a lath
brought to the surface, then hand split with a ham- roof. Lath roofs are not uncommon in the U.S. but
mer and chisel into thin sheets about a quarter of an they are not preferable to solid board decks, as we
inch thick (more or less). These slate shingles are will discuss later.
then trimmed into particular shapes, usually 2) Full one-inch-thick, local, green or air-
punched for nail holes, and are then ready to be dried lumber boards are used for roof sheathing, or
installed on a roof. They typically come from other comparable roof decking material such as 3/4”
American quarries already trimmed and punched, kiln dried boards, tongue-in-groove boards, or 1½" t-
so the roof installer only needs to know how to put i-g lumber (more suitable for large institutional
them on the roof. buildings). Laminated woods, plywoods, particle
There is, however, no “one right way” to boards, and chip board decks are avoided.
install roof slates. The covering of roofs with stone is 3) The roof deck is covered with 30 lb. felt
an age-old tradition that has been practiced around paper — self-adhesive underlayments are not need-
the world for centuries. Different regions of the ed. Even the felt paper is optional.
world have their own traditional slate roof installa- 4) The slates are nailed onto the wooden
tion techniques. We will look at some of the various sheathing using two nails per standard slate (no
types of international installation methods in this adhesives are used). Four nails per slate may be used
chapter, but we will focus primarily on the tradition- in hurricane prone areas or when installing exces-
al American styles of slating. sively large, heavy slates. The nails recommended
Roof slates in the United States are tradi- today are copper or stainless steel, although most old

s Traditional British stone roofing style (above) involves the use of lath strips in the roof construction. This abandoned farm building is
located on the Yorkshire-Lancashire border in the UK. Close-up on following page. Photo by Dave Starkie.

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 143

 roofs used iron or galvanized steel.
5) A headlap measurement of three inches is
typically used (more for lower slopes or ice-dam con-
ditions).
6). Sidelaps, or the lateral spacing of the
slates in relation to the courses above and below,
should incorporate a minimum 3” overlap, if possi-
ble.
7) Slate roofs are installed on slopes greater
than four inches of run in twelve inches of rise,
although the most long-lasting roofs are installed on
slopes that are too steep to walk on.

1) SOLID WOOD ROOF SHEATHING

The slates are nailed onto a completely sheathed

roof deck — the roof deck is constructed of full
boards abutting each other so as to cover the entire
roof surface, leaving no, or negligible, gaps between
the boards, other than perhaps “toe-holds” or spaces
left between the boards for footholds during con-
struction. This is in contrast to the practice of nail-
ing the slates onto “slater’s lath,” which are narrow
strips of wood spaced evenly on top of, and perpen-
dicular to, the roof rafters so as to provide a place to
nail or hook the slate (as shown at left). Roof lath
construction only requires the bare minimum of
wood — just enough to provide an anchor for the
nails or hooks, and is therefore more conservative in
s Close-up of lath and peg roof construction on old abandoned farm
building in England showing the minimal amount of wood that can
the use of lumber. This is the preferred method of
support a stone roof. The slates were attached with wooden pegs, not construction in parts of Europe where many of the
nails. traditional buildings are constructed of stone or
masonry and wood is minimally used. American
t Solid wood sheathing (decking) made from local mixed hardwoods barns often have lath-type roofs, no doubt because of
only one week “off the stump.” This Pennsylvania outbuilding roof will
be slated with Vermont “sea green” slates. The finished roof can be
the lesser cost of the materials. Many homes in spe-
expected to last 150 years or longer. cific regions of the U.S. also have lath roofs, proba-
Top photo by Dave Starkie, bottom photo by Bob Sayre. bly reflecting the ethnicity of the people who built
them.
The practice of using roof lath to support
slate may have developed as a response to the scarci-
ty of forest resources in Wales and Europe in the
18th and 19th centuries. That scarcity did not exist
in the United States during that time, when most
roof decks were completely covered with wood as
opposed to just strips of lath. Perhaps this technique
can be traced back to Scottish ancestry, as the Scots
choose not to make their roofs of lath, but to use a
solid wood deck instead, for reasons we will discuss
later in this chapter. This turned out to be a good
idea for American roofs — it created a stronger, bet-
ter insulated roof that could withstand the snow
weights typical of the American northeast. A
stronger roof makes for a stronger building, and
144 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs
America’s wooden building styles benefited from a
roof of solid sheathing. Solid sheathing also provides
much more nailing surface, making it easier to
repair slate roofs, and therefore facilitating their
later restoration.
It’s interesting to note that roof slates in
Wales were originally “hung” on roof lath using only
wooden pegs driven through the slates (as shown at
right). The thin lath were stripped, not sawn, from
local logs. The hardwood pegs were split down to the
size of a pencil stub from a block of wood, and a sin-
gle peg was driven through the top center of the slate
so that the peg was flush with the front of the slate,
which was then hung on the lath. The heavy weight
of the slates overlapping each other held the roof
together.
Today, the Welsh use a modified version of
the lath and peg system, which we will look at later
in this chapter.

2) USE SOLID LUMBER s A “stone slate” from a 16th century abbey in Wales showing the
actual peg and lath used in the construction of the roof.

Full one-inch-thick, local lumber boards

have been traditionally used for roof sheathing, t The author replacing a valley on a century-old, American barn with
white oak lath construction. Note the deplorable condition of the dis-
unplaned, not tongue-in-groove, and not kiln dried. integrated terne metal valley, 34 feet long, draping between the lath
The author stayed in a house in Scotland, built in strips like paper. The oak lath was still solid, however, making the val-
ley replacement a routine job. Imagine the nightmare if the barn had
1785 and still covered by its original slate roof been sheathed in a shorter-lived laminated wood, which would have
(restored). The existing 215-year-old roof sheathing delaminated, rotted, and warped along the entire length of the valley!
was made of 1” rough-sawn lumber. Kiln-dried and
planed lumber, although not as commonly used a
Top photo by author, bottom photo by Umberto Perlino.
century ago probably due to the extra and unneces-
sary expense of drying and planing, has also been
proven to work well as a roof deck under slate.
Green lumber is not kiln dried, and may not
even be air dried, but it still makes a great roof deck.
The boards simply dry in place after being nailed to
the rafters. When fully dry, they’ll have a gap
between them of about 1/2” (wood shrinks more
width-wise than lengthwise by a factor of seven).
Some contractors may insist that the boards will
warp, crack, and twist when they dry, but when
nailed properly, the boards will remain flat.
In fact, many hardwoods such as oak must be
used green. When completely dry they’re too hard
— nails won’t penetrate them without bending. It’s
worth mentioning that a tree felled in the winter
when the sap is down will dry more quickly and
shrink less than one felled when the sap is up.
A one-inch-thick, solid wood roof deck is a
strong, durable one which will last for centuries.
And if a leak damages part of the roof sheathing, it
can simply be cut out and replaced with the same
material — local lumber.
The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 145
 Local lumber can be air dried, which simply boards will vary as much as 1/2” (or more) in thick-
means that the lumber is “stickered” for a few weeks ness or width from one end to another. If you do run
or months before using. Stickering lumber means across a bad board in your lumber, set it aside and
stacking it with dry sticks of uniform thickness use it for something else — not for the roof. If you
(about an inch) between the layers of boards so air find a board with an excessively large knot or other
can circulate around the lumber, thereby drying it defect, cut the defect out before using the board, or
out. However, when building, framing or sheathing don’t use it at all. This is one of the simple tricks to
with green lumber, stickering is not necessary if the using local, green lumber (or any lumber) — sorting
lumber will be nailed in place within two weeks of out the bad boards, and you probably will have
cutting. If the lumber is going to sit around longer some. It’s the boards with the bad knots that are
than that, it should be stickered and protected from likely to warp when drying. When nailing the boards
rain until it’s time to use it; otherwise it may devel- to the rafters, butt them firmly against each other,
op surface mold. both at their sides and at their ends, and nail them
Local lumber is typically only sold by the down tightly. The slates are nailed to the roof
sawyers who saw it; it usually needs to be ordered in sheathing while green; you need not wait for the
advance and the buyer may wait for weeks when wood to dry. The wood is felted while green as well
large quantities of specific species are ordered. It’s — it will dry in place (providing you’re not using
also “green” (undried) when you buy it. self-adhesive underlayments, which are not recom-
Furthermore, it’s heavier than the kiln-dried soft- mended).
woods typically sold by building material centers, A suitable alternative to local lumber for
and therefore it requires more effort to work with. roof decking is 3/4-inch-thick, planed, kiln-dried
Because of the extra effort in locating a sawyer, roof sheathing boards available from any lumber
ordering the lumber, waiting for it, hauling it, stick- yard. These are usually made of spruce, fir, or pine
ering it (if necessary), then lugging it up on the roof, and can be quite a bit more expensive than local
only the most conscientious of builders use it nowa- green lumber, but are certainly preferable to ply-
days. It is well worth finding those builders when wood. You can also use tongue-in-groove roof deck-
installing a slate roof if you want the roof to last. If ing under slate. One of the longest lasting roof
a contractor tells you he can’t use local lumber sheathing lumbers is white oak, although it is heavy
because it’s green and it will twist and warp, find and somewhat difficult to work with, and hard to
another contractor. And it’s well worth locating a nail into when dry.
local sawyer and ordering your roof decking directly Nail 3/4- or 1-inch-thick roof sheathing to
from him if you’re going to build your own roof. the rafters with eight penny common nails (2 1/2
You can locate local sawyers by looking inches long). Thicker decking will require longer
under “lumber-wholesale” in the yellow pages of nails.
your phone book. Rough-sawn lumber is full size —
a 1x8 is a full one inch by eight inches — therefore, THE PLYWOOD ROOF DECK CONTROVERSY
the “board feet” required for the job is actually the
square feet of roof area including overhang. When Unfortunately, a new generation of slate
ordering local lumber, always allow for at least 15% roofs is now being constructed in the United States
waste when figuring your total area, and more when using plywood roof decks, some as flimsy as 1/2”
valleys and hips are being built. Don’t deduct from thick — even on multi-million dollar homes! These
the total area for skylights or chimneys. roofs can present many headaches for the slate roof
Use #2 grade, one-inch-thick boards at least restoration professionals of the future when the ply-
6” wide. Preferred species are the softwoods such as wood begins to delaminate, sag, or rot.
white pine, yellow pine and hemlock, or the hard- Plywood is a material that is designed for
wood yellow poplar (tulip poplar) because they’re the convenience of the contractor, not for longevity.
lighter and therefore easier to work with, although Although it is a convenient material for the contrac-
almost any tree species suitable for lumber will do, tor and the architect, it should not be used on roofs
including oak, cherry, maple, ash, chestnut, birch expected to last a century or two. A slate roof will not
and beech. The boards do not need to be planed or be routinely ripped off and replaced every twenty
joined, or milled in any way, although it is important years like its asphalt cousin. Plywood has not yet
to get boards from a sawyer who does a good job of cut- proven to have any longevity approaching the phe-
ting his lumber. Some sawyers are sloppy and their nomenal life span of slate. Some argue that this is
146 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs
only because plywood hasn’t been on the market 3) NAILING THE SLATES
long enough to prove itself. On the contrary, ply-
wood has been used long enough on roofs to display Roof slates are nailed onto the wooden
an uncomfortable failure rate. For example, here’s a sheathing using two nails per standard thickness
quote from a roofing magazine: slate, the nails being approximately 1.25” to 1.5”
long and typically (on older roofs) made of hot-
“Though the building was only twelve dipped galvanized (zinc-plated) steel. Alternatively,
years old, the roof was leaking at every con- hardened copper nails of the proper length are used,
ceivable point. The original shingles were guar- which are the preferred nail on more expensive
anteed for twenty years, but poor ventilation homes and buildings with slate roofs and on new
had caused the plywood deck to delaminate in roof installations today. Stainless steel nails may be
many places, and shingles to blow off during preferable where older roof boards have hardened
high winds. The roof was repaired on a consis- with age, which is typical of southern yellow pine
tent basis, but the efforts were in vain due to and northern hardwoods. Roofs with thicker slates
the delamination of the plywood." require longer nails. The rule of thumb is that the
Quoted from Roofer Magazine, November, 1997: The Roof Doctor’s
Prescription for Success, by Melinda North (page 27).
nail length should be twice the thickness of the slate
plus one inch.
Today it’s often recommended that all ply- American roof slates are supplied by the
wood roof decks be covered with a self-adhesive manufacturer already pre-punched with nail holes,
underlayment along the eaves, under valleys, and in contrast to European roof slates, many of which
almost everywhere else on the roof deck in order to come from the quarry or mine without holes.
preserve the plywood. Not only is this more expen- American roofs tend to have solid sheathing, where-
sive than the traditional, tried-and-proven, wood as many European roofs tend to use slating lath, so
boards and 30 pound felt roofing system, it is also American slates can be pre-punched without worry
more time consuming and less ecologically sound. It as to whether the nail holes will line up with the
creates a roof deck that cannot breathe, adding new lath. Many European roofers must “hole” their
roof problems related to condensation and ventila- slates at the job site.
tion. Nail holes should just clear the top of the
Wood decks made of boards are composed of underlying slate. This allows the slate to lay best. If
pieces of wood perhaps six to twelve inches wide. In the holes are too low you’ll nail through the top of
between each of these boards is a small gap. This gap the underlying slate, which should be avoided. It’s
not only allows for the roof deck to breathe, but it much more difficult to remove and replace “double-
also allows for any water penetration to drip into the nailed” slates due to the inaccessibility of the upper
building and be quickly discovered (and repaired). pair of nails to the slate ripper. On the other hand, if
Neglected leaks on old roofs can rot the board the regular pair of nails are nailed too far up on the
underneath, but the rot will be localized and easily slate, the slates may not lie flat on the roof.
repairable — it is not inclined to spread. Plywood, The slates should not be nailed down too
on the other hand, is made up of four foot by eight tightly, but are actually “hung” on the roof nails, so
foot sheets of thin layers of wood glued together. If they can “float” on the roof, although nailing snugly
water penetrates the roof, the moisture wicks is OK. This prevents the slates from being subjected
through the sheet causing delamination and rot to to damaging pressures which can crack the slate
spread over a wider area. The plywood becomes over time, referred to as “over-nailing.” It takes
punky and soft — any roofer who has put his foot some practice to nail roof slates properly, but it isn’t
through rotten plywood knows exactly what I’m difficult. The nail holes are pre-punched so the
talking about. beveled side of the hole faces outward, allowing for
When slate roofs get to be a century old, they the nail head to sit down into the beveled hole,
may have suffered a lot of neglect. Although slate thereby preventing the nail from rubbing against the
roofs are fantastically successful roof systems, a lot slate over top of it and wearing a hole in it (referred
of bad things can happen to them in a century or to as “under-nailing”). When punching a hole in a
two. But because of the traditional methods of slate, the strike against the slate should be against
installation and the traditional materials used, there the back so the bevel appears on the side where the
is almost no problem that can afflict an old slate roof nail head is to rest.
that cannot be remedied. Traditional Scottish slating, as well as other
The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 147
older UK and European slating styles, require a sin- ing the living space and infiltrating the roof space.
gle nail or peg at the top center of the slate or stone,
known as “head-nailing.” Standard American nail- FRAMING THE ROOF
ing is known in Europe as “center-nailing.” This will
be discussed in greater detail later in this chapter. Slate is heavy — standard 3/16” thick slate
weighs about 700 pounds per square (100 square feet
A BRIEF WORD ABOUT VENTILATING SLATE of finished roof) when new. This is about three times
as much weight as standard asphalt shingle roof
Roof slate rock does not need to be ventilat- material, and it raises concerns among people who
ed. Exposure to air, sunlight, and heat all slowly are afraid their structure won’t stand up to the heavy
cause slate rock to deteriorate. The longest lasting load of slate. How should a slate roof be framed?
slate is the rock that’s left in the ground unexposed What are safe timber sizes and spans?
to air. When you pry a century old slate off a roof Many older homes have 2x10 rafters on two
and look at the back of it, you will see that those foot centers and this has proven to work well.
parts of the slate that had been in direct contact with However, rarely is a 16’ span on a rafter left unsup-
the felt paper underneath with no exposure to air ported without an inside wall or collar brace. It’s
whatsoever are in the best condition. The greater recommended that a 2x10 rafter on two foot centers
exposure to air, the more deterioration. This is espe- not exceed 10’ in unsupported span (see chart).
cially evident on old lath roofs where the part of the Many older slate roofs have only 2x5 or 3x5 rafters
back of the slate contacting the lath remains sound, on two foot centers and have easily withstood a cen-
but the part between the lath exposed to air is flak- tury of time, although the rafters tend to be oak or
ing and delaminating. Is it wrong to ventilate the another strong hardwood, and are usually braced
slates? No, but it’s definitely not necessary. with collar ties and/or inside walls. And of course,
This is not to be confused with the ventila- the solid sheathing adds to the strength of the roof.
tion of the roof itself. Roofs should be able to The author has designed and/or built many
breathe. Modern American roofing methods that roofs, all of local (green) lumber, as was the style
utilize plywood, self-adhesive underlayments, and when most slate roofs were originally constructed at
asphalt shingles create roofs that can’t “breathe” and the turn of the last century. Building with full-sized,
instead have ventilation problems. These roofs must unplaned, rough sawn, green local lumber requires
have a ventilation system installed, usually through no special tools or equipment, and it allows for the
the ridge, but also out the gable ends or through construction of a solid, long-lasting roof. Again, the
other roof vents. lumber shrinks and dries in place, causing no detri-
Interior roof spaces and attics on slate roofs ment to the structure or the roof. Instead, the struc-
should be ventilated if unheated. The airflow can be ture becomes stronger as the lumber dries. This style
out gable end louvers, through roof vents, or via of construction has been achieved on millions of
ridge vents designed specifically for slate roofs. buildings across the USA. Most of the men who built
Gable vents are preferable as they keep obstructions local-lumber buildings are dead, however, as are the
off the roof. slaters who roofed the buildings. Many of today’s
Any warm air that comes into contact with a modern builders and architects have discarded the
cold surface will cause condensation. In cold cli- traditional building methods for ones that focus on
mates, if warm household air is entering the roof contractor convenience. And now, unfortunately, it’s
space and coming in contact with the underside of difficult to find people in the building trades with
the cold roof sheathing, then water droplets will knowledge of traditional building methods and
form on the inside of the sheathing, thereby creating materials.
a condensation problem. Adequate insulation and As we are beginning to see, there are a num-
proper ventilating techniques will keep the under- ber of factors involved in determining the strength
side of the roof sheathing at the same temperature as of the roof. First, the weight of the roofing must be
the ambient outdoor temperature, preventing con- taken into consideration. Secondly, the type of lum-
densation. When insulating between rafters, leave ber must be noted, as some lumber species are much
an air space between the insulation and the roof stronger than others. Thirdly, the size and spans of
sheathing boards, if possible. Always install a vapor the framing members are important, as unsupported
barrier, such as a sheet of plastic, interior to the insu- spans that are too long will sag over time. And last-
lation, in order to prevent warm, moist air from exit- ly, the slope of the roof is important, as the lower the
148 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs
slope of the roof, the more snow weight it must bear, larger roofs, and smaller slates on smaller ones (this
while the steeper the roof, the more wind-force it rule is frequently broken). Larger slates go on faster,
must withstand (see chart). as fewer are required to cover a given area. The
The rule of thumb on slate roof slope is largest standard size is 14” wide by 24” long, and
never to go below a 4:12 pitch. The lower the pitch, only 98 of these will cover one hundred square feet
the longer the headlap, so that a 4:12 roof requires a of roof surface with a three inch headlap, using
4 inch headlap. The steeper the roof, the shorter the about 200 nails. An 8x10 slate, on the other hand,
headlap, so that a 12:12 roof can get by with only a requires 514 slates to cover the same area, and about
two inch headlap, although a 3” headlap is recom- 1,028 nails. Obviously then, the larger slates require
mended. Most slate roofs have a slope between 8:12 less time and labor to install.
and 12:12, while 10:12 is perhaps the most common. Some styles of laying slate were developed in
order to conserve materials, such as the Dutch Lap
INSTALLING SLATE (or “side-lap”), Open Slating, and “French” meth-
ods, which require far fewer slates to cover a roof
Slates have a top and bottom, front and back, than the standard overlap pattern does. These styles
and they must be oriented properly on the roof. In tend to be found on barns and outbuildings where
general, always lay the slate face out and top up. the owner probably didn’t want to spend extra
Furthermore, butt the slates against each other on money on materials. The main problem with these
the sides. There is no advantage to leaving a space conservative slating styles is that the roofs are diffi-
between the slates. The slates will not expand and cult to restore properly when they get old. The stan-
contract and push against each other as wood does. dard lap style is ingenious in that it allows for easy
Most older slate roofs in America are laid in replacement of any broken slates in such a manner
a standard pattern consisting of slates that are, on that the nail holding the replacement slate is cov-
each roof, virtually all the same width, length, and ered by flashing and therefore rendered leakproof,
thickness (3/16” to 1/4” is standard thickness). It is or else a slate hook is used and no flashing at all is
not uncommon for slate roofs to be made of slates of required. Side-lapped slates do not allow the nail
random widths, or with staggered butts, or ragged and bib option for replacement slates and one is
butts, or with slates that vary in both length and instead limited to the use of slate hooks or face nails
width (graduated roofs — to be discussed later), or (see Chapter 17). Also, these alternative slating
that vary in thickness, or all of the above. All of these methods leave much of the roof area covered by only
styles of slating must always follow two fundamental a single layer of slate — a situation more vulnerable
rules: sufficient headlap and sufficient sidelap must to such threats as hail damage. Therefore, when
always be incorporated into the laying of the slate. installing a slate roof, it’s recommended that the
Headlap is the overlap each slate has in relation to slates be laid in a standard lap fashion. Of course,
the second course below it. Sidelap is the lateral some traditional European styles of slating, notably
spacing of the slots (where the sides of the slate abut the Old German style, require that all slates be side-
one another) in relation to the slots on the course lapped. However, of the traditional American slating
above and below. styles, standard overlapping has proven to be the
A rule of thumb is to use larger slates on most durable, waterproof, strongest, and easiest to

Front

Nail holes are punched from

the back of the slate so that
Nail holes the front of the hole is knocked
should just out, thereby becoming
clear the Back beveled and allowing for the
top of the nail head to sit into the slate.
underlying This prevents the nail head
slate within from rubbing on the overlying
an inch or slate and wearing a hole in it.
two.

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 149

 NAILS NUMBER OF SLATES AND NAILS FOR 100 SQUARE FEET OF ROOF

Correct nail length is twice the thickness of the slates plus FOR STANDARD THICKNESS (3/16” TO 1/4”) SLATES USING 1.5” NAILS
one inch (nail length=slate thicknessX2+1”).
APPROXIMATE WEIGHT OF
Recommended nails for new slate installations include solid cop- NAILS (POUNDS)
SIZE OF EXPOSED # SLATES # SLATES SPACING
per or stainless steel. Type 304 stainless nails are made of nick- SLATE LENGTH 3” 4” COPPER STAINLESS OF
el/chromium stainless steel. Type 316 contains slightly more (INCHES) (INCHES) HEADLAP HEADLAP GALV. 11 GA. 11 GA LATH

nickel than Type 304 as well as 2-3% molybdenum, making it 6x10 . . . .3 1/2 . . . . .686 . . . . . . . . . . . . . . .7 7/8 . . . .8.85 . .8.07 . . .3 1/2
more resistant to corrosion caused by sea water or sulphuric 7x10 . . . .3 1/2 . . . . .588 . . . . . . . . . . . . . . .6 3/4 . . . .7.58 . .6.91 . . .3 1/2
acid. Both types of stainless show negligible weight loss and no 8x10 . . . .3 1/2 . . . . .514 . . . . . . . . . . . . . . .5 7/8 . . . .6.63 . .6.04 . . .3 1/2
corrosion when tested under one year of accelerated exposure. 6x12 . . . .4 1/2 . . . . .533 . . . . . . . . . . . . . . .6 . . . . . . .6.87 . .6.27 . . .4 1/2
Under the same exposure, copper nails show a 26-28% weight 7x12 . . . .4 1/2 . . . . .457 . . . . . . . . . . . . . . .5 1/4 . . . .5.89 . .5.37 . . .4 1/2
loss and visible corrosion, while aluminum nails show a 32% 8x12 . . . .4 1/2 . . . . .400 . . . . . . . . . . . . . . .4 5/8 . . . .5.16 . .4.70 . . .4 1/2
weight loss and pronounced corrosion, and electrogalvanized 9x12 . . . .4 1/2 . . . . .355 . . . . . . . . . . . . . . .4 1/8 . . . .4.58 . .4.18 . . .4 1/2
nails show a 100% weight loss and complete corrosion. 10x12 . . .4 1/2 . . . . .320 . . . . . . . . . . . . . . .3 5/8 . . . .4.13 . .3.76 . . .4 1/2
7x14 . . . .5 1/2 . . . . .374 . . . . . . . . . . . . . . .4 1/4 . . . .4.82 . .4.40 . . .5 1/2
(Source: Swan Secure Products, Fasten Data 105) 8x14 . . . .5 1/2 . . . . .327 . . . . . . . . . . . . . . .3 3/4 . . . .4.22 . .3.85 . . .5 1/2
9x14 . . . .5 1/2 . . . . .290 . . . . . . . . . . . . . . .3 3/8 . . . .3.74 . .3.41 . . .5 1/2
LENGTH SHANK DIA. COPPER COPPER STAINLESS STAINLESS
(INCHES) GAUGE (INCHES) HEAD DIA. COUNT/LB HEAD DIA. COUNT/LB 10x14 . . .5 1/2 . . . . .261 . . . .288 . . . . . . .3 . . . . . . .3.37 . .3.07 . . .5 1/2
12x14 . . .5 1/2 . . . . .218 . . . .240 . . . . . . .2 1/2 . . . .2.81 . .2.56 . . .5 1/2
3/4 . . .12 . . ..109 . . . .21/64 . . . . .360 . . . . .5/16 . . . . . .380 8x16 . . . .6 1/2 . . . . .277 . . . .300 . . . . . . .3 1/8 . . . .3.57 . .3.26 . . .6 1/2
1 . . . . .12 . . ..109 . . . .21/64 . . . . .288 . . . . .5/16 . . . . . .348 9x16 . . . . 6 1/2 . . . .246 . . . .256 . . . . . . .3 . . . . . . .3.17 . .2.89 . . .6 1/2
1.25 . .12 . . ..109 . . . .21/64 . . . . .236 . . . . .5/16 . . . . . .255 10x16 . . .6 1/2 . . . . .222 . . . .230.40 . . . .2 1/2 . . . .2.86 . .2.61 . . .6 1/2
1.5 . . .12 . . ..109 . . . .21/64 . . . . .202 . . . . .5/16 . . . . . .218 12x16 . . .6 1/2 . . . . .185 . . . .192 . . . . . . .2 1/8 . . . .2.39 . .2.18 . . .6 1/2
1.75 . .12 . . ..109 . . . .21/64 . . . . .176 . . . . .5/16 . . . . . .189 9x18 . . . .7 1/2 . . . . .213 . . . .220.69 . . . .2 1/2 . . . .2.75 . .2.50 . . .7 1/2
2 . . . . .12 . . ..109 . . . .21/64 . . . . .156 . . . . .5/16 . . . . . .170 10x18 . . . 7 1/2 . . . .192 . . . .198.63 . . . .2 1/4 . . . .2.48 . .2.26 . . .7 1/2
3/4 . . .11 . . ..120 . . . .3/8 . . . . . . .302 . . . . .11/32 . . . . .323 11x18 . . .7 1/2 . . . . .175 . . . . . . . . . . . . . . .2 . . . . . . .2.26 . .2.06 . . .7 1/2
1 . . . . .11 . . ..120 . . . .3/8 . . . . . . .229 . . . . .11/32 . . . . .244 12x18 . . .7 1/2 . . . . .160 . . . .171.43 . . . .1 7/8 . . . .2.06 . .1.88 . . .7 1/2
1.25 . .11 . . ..120 . . . .3/8 . . . . . . .187 . . . . .11/32 . . . . .199 10x20 . . .8 1/2 . . . . .170 . . . .180 . . . . . . .2 3/8 . . . .2.19 . .2.00 . . .8 1/2
1.5 . . .11 . . ..120 . . . .3/8 . . . . . . .155 . . . . .11/32 . . . . .170 11x20 . . .8 1/2 . . . . .154 . . . . . . . . . . . . . . .2 1/8 . . . .1.99 . .1.81 . . .8 1/2
1.75 . .11 . . ..120 . . . .3/8 . . . . . . .139 . . . . .11/32 . . . . .149 12x20 . . .8 1/2 . . . . .141 . . . .150 . . . . . . .2 . . . . . . .1.82 . .1.66 . . .8 1/2
2 . . . . .11 . . ..120 . . . .3/8 . . . . . . .124 . . . . .11/32 . . . . .136 14x20 . . .8 1/2 . . . . .121 . . . . . . . . . . . . . . .1 7/8 . . . .1.56 . .1.42 . . .8 1/2
1 . . . . .10 . . ..134 . . . .7/16 . . . . . .187 . . . . .3/8 . . . . . . .212 11x22 . . .9 1/2 . . . . .138 . . . .145.46 . . . .2 . . . . . . .1.78 . .1.62 . . .9 1/2
12x22 . . .9 1/2 . . . . .126 . . . .133.34 . . . .1 3/4 . . . .1.63 . .1.48 . . .9 1/2
1.25 . .10 . . ..134 . . . .7/16 . . . . . .147 . . . . .3/8 . . . . . . .166
14x22 . . .9 1/2 . . . . .109 . . . . . . . . . . . . . . .1 1/2 . . . .1.41 . .1.28 . . .9 1/2
1.5 . . .10 . . ..134 . . . .7/16 . . . . . .123 . . . . .3/8 . . . . . . .139
12x24 . . .10 1/2 . . . .114 . . . .120 . . . . . . .1 5/8 . . . .1.47 . .1.34 . . .10 1/2
1.75 . .10 . . ..134 . . . .7/16 . . . . . .112 . . . . .3/8 . . . . . . .126
14x24 . . .10 1/2 . . .98 . . . . .102.86 . . . .1 3/8 . . . .1.26 . .1.15 . . .10 1/2
2 . . . . .10 . . ..134 . . . .7/16 . . . . . .93 . . . . . .3/8 . . . . . . .105
2.5 . . .10 . . ..134 . . . .7/16 . . . . . .81 . . . . . .3/8 . . . . . . .91 [Sources: Radford’s Estimating and Contracting (1913), p. 252; and Slate Roofs (1926), p.
3 . . . . .10 . . ..134 . . . .7/16 . . . . . .67 . . . . . .3/8 . . . . . . .78 12; # slates for 4” headlap from Slating and Tiling by J. Millar, 1937, pp. 21-22]

Copper or stainless steel nails are the preferred fastener for new slate roof installations. However, most old slate roofs were fastened with
iron or steel nails such as those shown above right, taken from actual slate roofs of the age indicated. It is a very common claim that old
slate roofs should be condemned because iron or steel nails were used to fasten the slates, a claim that does not bear up under scrutiny.
The old galvanized nails on the left were installed in 1919 and were removed during the replacement of a valley at 82 years of age, in very
good condition. The old cut steel nails above right, also removed during a valley replacement, were installed in 1890, and at 111 years of
age are in excellent condition. Although nails are sometimes a cause of slate roof failure, they usually are not to blame.

150 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

maintain and restore. waterproof material — it is now full of holes from
Another style of slating that has been dis- the slate nails and is no longer needed anyway. The
credited and should be avoided at all costs is what slate, properly installed, will not leak. Instead, the
has been known as the “economy method.” This felt will slowly dry up under the slate until it turns
method eliminates the most critical element of a into a powder a century or so later.
successful slate roof installation — head-lap, and Newly installed roof sheathing should be
instead utilizes a strip of felt paper between each covered with one horizontally laid layer of felt paper
row of slates to prevent water from penetrating in overlapped about three inches at the top edges, six
the slots between the slates. Although this looks like inches at the sides, and nailed to the roof with 1”
a normal slate roof after installation, as soon as the hot-dipped or electro-galvanized roofing nails or
felt paper wears out, the roof leaks, cannot be other suitable nails such as plastic cap simplex nails.
repaired, and must be entirely re-slated in a proper The nail spacing at all edges is approximately every
manner, with headlap. This style of slating is only six inches. In the center of the paper a diamond-
done by contractors who are totally ignorant about shaped nail pattern is followed. If the felt paper
how a slate roof works, or totally unconcerned with must act as a temporary roof for a prolonged period
the quality or longevity of their work. (for example, over winter), then skim over each and
It should also be mentioned that, no matter every nail head with roof cement. This is not as big
how much headlap is used, felt paper should never a job as it sounds, and it will keep the water out of
be laid between the rows of slate during installation the roof until the slate is installed. Vertical strips of
as is done with wooden shake roofs. The felt paper wood may be necessary in order to hold the felt in
on a slate roof is always completely underneath the place over a prolonged period of time, especially
slates and never between the courses. Remember under windy conditions. Horizontal strips of wood
that you are creating a roof that should last a centu- will dam water on the roof and can leak like crazy.
ry or two, and that it should be installed with future Felt paper isn’t absolutely necessary for the
maintenance in mind. At some point in time some of slate roof to function; many slate roofs, primarily
the individual slates will need to be replaced for any barn roofs, don’t have any felt paper at all and are
number of reasons, including an accidental hit by a still leak free after a century, with proper mainte-
baseball, for example. When felt paper is layered nance. Felt paper does, however, provide a tempo-
between the courses of slates, it severely inhibits the rary cover in the event of rain during installation. It
use of a slate ripper, which slides under the slate in also helps to insulate and waterproof the roof and
order to hook the nails and remove it. The felt cushion the slates. It also provides a suitable surface
bunches up and turns an easy job into a headache. for chalk lines when installing a slate roof, so it is
Today it’s common to see new slate roofs laid recommended to use 30 lb. felt in order to do the
with a random width pattern — the slates are all the best job. For better protection, the 30 lb. felt can be
same length, but the widths are random. Random installed in the “half-lap” fashion so two layers of
width slates can be slightly less expensive than uni- the felt protect the entire roof. For larger institution-
form width slates, and they work just as well, so al projects, a heavier felt such as a 55 pound smooth
they’re preferred by some roofers. The joints, or felt may be preferred.
slots between the slates should have at least 3” of lat-
eral spacing where they overlap the course below, SELF-ADHESIVE UNDERLAYMENTS
and this little bit of extra critical detail when laying
the slate increases the overall labor time involved Most American slate roofs were installed
when installing a random width roof. about a century ago and the people who installed
them are now long dead and gone. What they left
UNDERLAYMENT behind was evidence of a simple, yet brilliant roof-
ing system: stone on wood. Many thousands of these
The underlayment is the waterproofing layer century-old homes still have roofs in good working
that exists between the wood roof deck and the order today consisting of nothing but slate over
slates, typically 30 pound felt paper (weighing 30 wood. The old roofers must have done something
per 100 square feet of roof). Its primary purpose is to right.
provide temporary waterproofing while the finished In the interim, however, American roofers
slate roof is being installed. Once the slate is abandoned permanent roofing almost totally in
installed, the underlayment becomes obsolete as a favor of throw-away asphalt roofs. Asphalt roofs
The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 151
 GENERAL CHARACTERISTICS OF WOOD PARTS OF A SLATE Top
1) Degree of workability with hand tools; 2) Tendency to warp; 3) Tendency to (points toward top
shrink or swell; 4) Relative hardness; 5) Comparative weight of roof). Nail holes
H = High, I = Intermediate, L = Low
Nail Holes are on the top half.
Species 1 2 3 4 5

Black Ash . . . . . . . . . . . . .L . . . . . . .I . . . . . . .H . . . . . . .H . . . . . .I Face

White Ash . . . . . . . . . . . .L . . . . . . .I . . . . . . .I . . . . . . .H . . . . . .H Front
(exposed part —
Basswood . . . . . . . . . . . .H . . . . . . .I . . . . . . .H . . . . . . .L . . . . . .L (faces the sky)
what you see when
Beech . . . . . . . . . . . . . . .L . . . . . . .H . . . . . .H . . . . . . .H . . . . . .H The front has the
nailed on roof)
Yellow Birch . . . . . . . . . . .L . . . . . . .I . . . . . . .H . . . . . . .H . . . . . .H beveled edge
Eastern Red Cedar . . . . .I . . . . . . .L . . . . . . .L . . . . . . .H . . . . . .H exposed.
Western Red Cedar . . . . .H . . . . . . .L . . . . . . .L . . . . . . .L . . . . . .L Back
Northern White Cedar . . .H . . . . . . .L . . . . . . .L . . . . . . .L . . . . . .L (faces the roof) Bottom
Southern White Cedar . . .H . . . . . . .L . . . . . . .L . . . . . . .L . . . . . .L (points
Does not have toward bot-
Cherry . . . . . . . . . . . . . . .L . . . . . . .L . . . . . . .I . . . . . . .H . . . . . .I beveled edge. tom of roof)
Chestnut . . . . . . . . . . . . .I . . . . . . .L . . . . . . .I . . . . . . .I . . . . . .I
Cottonwood . . . . . . . . . . .I . . . . . . .H . . . . . .H . . . . . . .L . . . . . .I
Southern Cypress . . . . . .I . . . . . . .I . . . . . . .I . . . . . . .I . . . . . .I
Rock Elm . . . . . . . . . . . . .L . . . . . . .I . . . . . . .H . . . . . . .H . . . . . .H
Soft Elm . . . . . . . . . . . . . .L . . . . . . .H . . . . . .H . . . . . . .H . . . . . .H
Balsam Fir . . . . . . . . . . . .I . . . . . . .I . . . . . . .I . . . . . . .L . . . . . .L
Douglas Fir . . . . . . . . . . .L . . . . . . .I . . . . . . .I . . . . . . .I . . . . . .I
White Fir . . . . . . . . . . . . .I . . . . . . .I . . . . . . .I . . . . . . .L . . . . . .L
Red Gum . . . . . . . . . . . . .I . . . . . . .H . . . . . .H . . . . . . .I . . . . . .I
Eastern Hemlock . . . . . . .I . . . . . . .I . . . . . . .I . . . . . . .I . . . . . .I
Western Hemlock . . . . . .I . . . . . . .I . . . . . . .I . . . . . . .I . . . . . .I
Pecan Hickory . . . . . . . . .L . . . . . . .I . . . . . . .H . . . . . . .H . . . . . .H
True Hickory . . . . . . . . . .L . . . . . . .I . . . . . . .H . . . . . . .H . . . . . .H
Western Larch . . . . . . . . .L . . . . . . .I . . . . . . .I . . . . . . .H . . . . . .H
Black Locust . . . . . . . . . .L . . . . . . .I . . . . . . .I . . . . . . .H . . . . . .H
Honey Locust . . . . . . . . . .L . . . . . . .I . . . . . . .I . . . . . . .H . . . . . .H
Mahogany . . . . . . . . . . . .I . . . . . . .L . . . . . . .I . . . . . . .H . . . . . .H
Hard Maple . . . . . . . . . . .L . . . . . . .I . . . . . . .H . . . . . . .H . . . . . .H
Soft Maple . . . . . . . . . . . .L . . . . . . .I . . . . . . .I . . . . . . .H . . . . . .H
Red Oak . . . . . . . . . . . . .L . . . . . . .I . . . . . . .H . . . . . . .H . . . . . .H
White Oak . . . . . . . . . . . .L . . . . . . .I . . . . . . .H . . . . . . .H . . . . . .H
Ponderosa Pine . . . . . . . .H . . . . . . .L . . . . . . .I . . . . . . .L . . . . . .I
Arkansas Soft Pine . . . . .H . . . . . . .L . . . . . . .L . . . . . . .L . . . . . .L
Sugar Pine . . . . . . . . . . . .H . . . . . . .L . . . . . . .L . . . . . . .L . . . . . .L
N. White Pine . . . . . . . . .H . . . . . . .L . . . . . . .L . . . . . . .L . . . . . .L
W. White Pine . . . . . . . . .H . . . . . . .L . . . . . . .I . . . . . . .L . . . . . .I
S. Yellow Pine . . . . . . . . .L . . . . . . .I . . . . . . .I . . . . . . .H . . . . . .H GREEN
Yellow Poplar . . . . . . . . . .H . . . . . . .L . . . . . . .I . . . . . . .L . . . . . .I LUMBER is air
Redwood . . . . . . . . . . . . .I . . . . . . .L . . . . . . .L . . . . . . .I . . . . . .I dried by “stickering” it
E. Spruce . . . . . . . . . . . . .I . . . . . . .L . . . . . . .I . . . . . . .L . . . . . .I — stacking it with dry, one
Sitka Spruce . . . . . . . . . .I . . . . . . .L . . . . . . .I . . . . . . .L . . . . . .I inch wooden spacers between
Sycamore . . . . . . . . . . . .L . . . . . . .H . . . . . .H . . . . . . .H . . . . . .H rows of boards, then covering it to keep
Tupelo . . . . . . . . . . . . . . .L . . . . . . .H . . . . . .I . . . . . . .H . . . . . .H the rain off.
Walnut . . . . . . . . . . . . . . .I . . . . . . .L . . . . . . .I . . . . . . .H . . . . . .H
(Source: H. E. Brosius Co., Kittanning, PA; Home Handbook (1956), p. 4)

AVERAGE WEIGHT OF TIMBER APPROX. WEIGHT OF DRY LUMBER PER

LUMBER GRADES 1000 BOARD FEET
Common or Board Lumber Species Weight (lbs/cu. ft) Species Weight (lbs)

No. 1: Best quality, most expensive, gen- Ash . . . . . . . . . . . . . . . . . . . . . .42 Ash . . . . . . . . . . . . . . . . . . . .3,500
erally clear of knots, but may have Chestnut . . . . . . . . . . . . . . . . . .41 Chestnut . . . . . . . . . . . . . . . .3,400
small, tight knots. Hemlock . . . . . . . . . . . . . . . . . . .25 Hemlock . . . . . . . . . . . . . . . .2,100
No. 2: All around utility grade. Ideal for Hickory . . . . . . . . . . . . . . . . . . . .53 Hickory . . . . . . . . . . . . . . . . .4,400
roof construction. May have occasional Maple . . . . . . . . . . . . . . . . . . . . .49 Maple . . . . . . . . . . . . . . . . . .4,100
wood defects that need to be cut out. Oak . . . . . . . . . . . . . . . . . . . . . .32-48 Oak . . . . . . . . . . . . . . . . . . . .4,000
No. 3: May have knot holes. Lower grade Norway Pine . . . . . . . . . . . . . . .36 Norway Pine . . . . . . . . . . . . .3,000
than #2. N. Yellow Pine . . . . . . . . . . . . . .34 White Pine . . . . . . . . . . . . . .2,100
No. 4: Lowest grade generally consid- S. Yellow Pine . . . . . . . . . . . . . .45 Yellow Pine . . . . . . . . . . . . . .3,000
ered usable for construction of any Spruce . . . . . . . . . . . . . . . . . . . .25 Spruce . . . . . . . . . . . . . . . . .2,100
Walnut . . . . . . . . . . . . . . . . . . . .48 Walnut . . . . . . . . . . . . . . . . .4,000
kind.
No. 5: Not suitable for construction.

152 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

 AVG. WEIGHT OF SLATE ROOF
(per 100 Square Feet Coverage) WEIGHT OF SLATE ROOF PER 100 SQUARE FEET (SQUARE)

Thickness Weight (lbs) Slate

Length (in.) Weight in Pounds/Square for Thickness (in.) Shown
3/16” . . . . . . . . . . . . . . . 700-750
1/4” . . . . . . . . . . . . . . . . 1,000 1/8 3/16 1/4 3/8 1/2 5/8 3/4 1
3/8” . . . . . . . . . . . . . . . . 1,500 12 480 725 968 1450 1938 2420 2900 3870
1/2” . . . . . . . . . . . . . . . . 2,000 14 460 688 920 1370 1845 2300 2760 3685
3/4” . . . . . . . . . . . . . . . . 3,000 16 445 668 890 1336 1785 2230 2670 3568
1” . . . . . . . . . . . . . . . . . . 4,000 18 435 650 870 1305 1740 2175 2608 3480
1 1/4” . . . . . . . . . . . . . . 5,000 20 425 638 850 1276 1705 2130 2555 3408
1 1/2” . . . . . . . . . . . . . . 6,000 22 418 625 836 1255 1675 2094 2508 3350
1 3/4” . . . . . . . . . . . . . . 7,000 24 412 616 825 1238 1655 2066 2478 3307
2” . . . . . . . . . . . . . . . . . . 8,000 26 408 610 815 1222 1630 2039 2445 3265
[Source: Slate Roofs (author unknown), 1926, page 13] [Source: Radford, Wm. A. (1913), Radford’s Estimating and Contracting; Radford Architectural Co., Chicago, p.253]

APPROXIMATE WEIGHT OF SLATE STONE (NOT ROOF) PER SQUARE FOOT

Thickness (inches) 1/8 3/16 1/4 3/8 1/2 5/8 3/4 1

Weight (pounds)/ft2 1.80 2.70 3.62 5.47 7.25 9.06 10.9 14.5

[Source: Radford’s Estimating and Contracting, 1913, p. 253]

RECOMMENDED RAFTER SIZES FOR RIGID CONSTRUCTION

Rafter spacing,
(inches on center) 12” 16” 24”

Unsupported
Span
[when 50 lbs/ft2 live load (e.g. snow weight) anticipated]
6 ft. . . . . . . . . . . . . . . . 2x6 . . . . . . . . . . 2x6 . . . . . . . . . 2x6
8 ft. . . . . . . . . . . . . . . . 2x6 . . . . . . . . . . 2x6, 3x6 . . . . . 2x8, 3x6
10 ft. . . . . . . . . . . . . . . 2x8, 3x6 . . . . . . 2x8, 3x6 . . . . . 3x8, 2x10
12 ft. . . . . . . . . . . . . . . 2x8, 3x8 . . . . . . 2x10, 3x8 . . . . 2x10, 3x10
14 ft. . . . . . . . . . . . . . . 2x10, 3x8 . . . . . 2x10, 2x12 . . . 3x10, 3x12
16 ft. . . . . . . . . . . . . . . 2x10, 3x10 . . . . 3x10, 3x12 . . . 3x12, 2x14
18 ft. . . . . . . . . . . . . . . 3x10, 3x12 . . . . 2x12, 3x12 . . . 2x14, 3x14
20 ft. . . . . . . . . . . . . . . 2x14, 3x12 . . . . 3x12, 3x14 . . . 3x14
22 ft. . . . . . . . . . . . . . . 2x14, 3x14 . . . . 3x14
24 ft. . . . . . . . . . . . . . . 3x14 . . . . . . . . . 3x14

[when 30 lbs/ft2 live load anticipated]

6 ft. . . . . . . . . . . . . . . 2x4 . . . . . . . . . 2x4,2x6 . . . . . . 2x6
8 ft. . . . . . . . . . . . . . . 2x6 . . . . . . . . . 2x6 . . . . . . . . . . 3x6, 2x6
10 ft. . . . . . . . . . . . . . 2x6, 3x6 . . . . . 2x8, 3x6 . . . . . . 2x8, 3x6
12 ft. . . . . . . . . . . . . . 2x8, 3x6 . . . . . 3x8, 3x8 . . . . . . 2x10, 3x8 Dead load = weight of roof rafter, sheathing and roof covering.
Live load = additional total weight roof may be subjected to, such as from
14 ft. . . . . . . . . . . . . . 2x8, 3x8 . . . . . 2x10, 3x8 . . . . . 2x10, 3x10 snow or wind.
16 ft. . . . . . . . . . . . . . 2x10, 3x10 . . . 2x10, 3x10 . . . . 2x12, 3x12
According to Slate Roofs (1926), roofs having a rise of 4 inches or less per
18 ft. . . . . . . . . . . . . . 2x10, 3x10 . . . 2x12, 3x12 . . . . 3x12, 2x14 foot of run, shall be assumed to have a vertical live load of 30 lbs. per
20 ft. . . . . . . . . . . . . . 2x12, 3x12 . . . 2x12, 3x12 . . . . 3x12, 3x14 square foot. A slope of more than 4:12, but less than 12:12 shall be
assumed to have a live load of 20 lbs. per square foot. Slopes exceeding
22 ft. . . . . . . . . . . . . . 2x14, 3x12 . . . 3x12, 3x14 . . . . 3x14
12:12 shall be assumed as having no vertical live load, although provi-
24 ft. . . . . . . . . . . . . . 3x12, 3x14 . . . 3x14 . . . . . . . . . 3x14 sions must be made to compensate for a wind force of 20 lbs per square
foot. In localities where snow loads are an important consideration, the
Rafter strength can vary greatly depending on species of wood. loadings shall be increased in accordance with local experience.
[Source: Slate Roofs (1926), author unknown, pp. 36-39.]

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 153

154 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs
The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 155
 A PICTURE IS WORTH A THOUSAND WORDS. It has become a common and widespread myth that slate roofs
are so heavy that they require extraordinary engineering and a massive roof frame underneath to support them.
American architects and builders are constantly talking owners out of new slate roofs on the grounds that their struc-
ture cannot withstand the weight of the roof. In reality, traditional slate roofs such as this very old one (above and
below) in Galicia, Spain, employing simple construction methods and using local materials sparingly, are a common
sight throughout Europe. They last for many generations and possess an enduring beauty that cannot be imitated
by artificial roofs.

These photos show how simple wooden poles gathered from the local environment created low-slope stone roofs
that have lasted generations and still have long lives remaining. Despite all of the expert opinions about how a slate
roof should be constructed today, an inspection of any old building with a sound slate roof will reveal the truth: nat-
ural materials and a variety of simple techniques will do the job quite nicely.

Slate roofs can be inadvertently under-built, which is a mistake that will show up in time as the rafters sag and the
roof bows. However, standard traditional solid construction techniques are adequate for most slate roofs. On the
opposite page, an ancient village spring in the Italian Alps is roofed with heavy stones on what appears to be a del-
icate framework (bottom). Roof slates are being removed and salvaged from a 120-year-old barn in Ohio, USA (top),
which is in the process of being refurbished. The framework of 2”x6” rafters and 1”x4” slating lath is common on
American barns.

Photos by author.

156 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 157
 WHEN STARTING TO SLATE A ROOF—
10 QUICK-REFERENCE STEPS

1) Make sure that the fascia is completely installed before slating the roof and
that the ends of the sheathing boards are firmly nailed.

2) Felt over the solid board decking (avoid plywood) with minimum 30 lb. roof-
ing felt, lapped at least three inches at the top. Felt paper is optional, but rec-
ommended.

3) Nail or screw a wooden cant strip at the bottom edge of the lowest sheath-
ing board — it should be 3/8” to 5/8” thick (standard slates only), and at least
an inch wide (eight foot lengths are convenient). Cedar or redwood is ideal
(cedar shim shingles will work), but the same lumber as the roof decking will do
fine (not plywood). Cant strip will be thicker when installing thicker slates.

4) Chalk a horizontal line on the felt paper for the top edge of the starter slates,
measuring the width of the slate up the bottom edge of the finished roof, deduct-
ing 1½ inches for the slate overhang. Then chalk a line for the first full row of
slates, now measuring up the roof the length of the slate and deducting 1½
inches for the overhang. Lay starter slates sideways, back side out.

5) Now measure up the remainder of the roof equal distances equivalent to the
exposure of the slate, and chalk lines accordingly. But first, make sure your sec-
ond full row of slates will overlap the starter row by a minimum of three inches
based on your measurements — if not, drop that second row down to where
you need it to be, then chalk the rest of the roof with the exposure measure-
ment. If laying the roof for a 4” headlap, adjust your chalk lines accordingly. If
slating in an ice-dam-prone area, lay the bottom three feet of the roof with a 4”
headlap and the remainder with a 3” headlap (assuming adequate slope —
slate roofs should be too steep to walk on for greatest longevity).

Exposure is determined by subtracting the headlap from the total length of the slate, then dividing the remainder in half. For example, a 20” slate with a 3” head-
lap will have an 8.5” exposure (20 - 3 = 17, divided in half = 8.5”). Although 3” headlap is standard, 4” headlap is required for lower slope slate roofs and for
ice-dam-prone sections of a roof.

6) Do not routinely bed the starter slates or any slates in roof cement or caulk. Adhesives make it very difficult to repair the roof in the future. Instead, a pair of
1½” copper or stainless steel nails per slate is a good rule of thumb which will ensure the secure attachment of all standard-thickness slates to the roof. Don’t
nail the slates too tightly; let them hang snugly on the roof. Do make sure the nail heads are set into the slate however, as nails that stick up will eventually wear
a hole in the overlying slate and cause a leak.

7) Tap a couple of temporary nails into the side of the fascia on the gable end, one at the top and one at the bottom, and run a string up the edge of the roof
positioned one inch out from the fascia. Use the string as a guide to align the outside edge of the slates as you nail them into place. Remove the string when
you’re done. Alternatively, chalk a vertical line on the felt up the edge of the roof, as illustrated above, as a guide for the end slates.

8) The butted sides of the slates on the first row must be staggered at least 3” laterally from the butted ends of the starter slates. All slates should have a min-
imum 3” lateral overlap in relation to the row of slates above or below.

9) You can work the first half dozen rows from a ground ladder or ground scaffold, then nail roof jacks and planks along the bottom of the roof and work up from
there. Use more jacks and planks as needed. Leave a slate out periodically in order to have a place to nail the roof jack. The missing slates can be installed
later with a stainless steel slate hook. See illustration this chapter.

10) Remember that all rules have exceptions in specific circumstances. Have fun! [Check jenkinsslate.com for instructional videos about slate installation.]

TOP ROW OF SLATES MAY NEED SHIMMED WHEN END SLATES CAN BE HALF SLATES
USING METAL RIDGE IN ORDER TO LAY FLAT. OR 1 & 1/2 SLATES

1/2 slate

1 & 1/2
slate

158 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

have to be replaced over and over again, which is functioning of a 150 or 200-year roof is only to fool
great for roofers but bad for homeowners and the oneself, or the home-owner.
environment. Asphalt roofs can conveniently be laid Self adhesive membrane is a product
over cheaper laminated roof decks — decks that designed to protect plywood from delamination —
have inherent weaknesses that are alleviated by such you will not need it on a slate roof. The author has
things as self-adhesive waterproof membranes. never used a square inch of it in his over 30-year
After a couple generations of installing 99% slate roofing career. Of course, this does not mean
asphalt roofs, plywood decks and membrane under- that you can install a low slope roof in a heavy snow
layments, many of today’s roofing contractors and load area and expect it to function well with a slate
architects can’t imagine anything else. Certainly a covering. If the slate roof system is poorly designed,
simple, natural roofing system such as stone on it can leak. The solution is not to beef up the under-
wood can’t work! Nothing that simple will keep layment, but to design the roof properly in the first
water out of a building. Or will it? place.
Slabs of stone worked into place with copper
flashing can’t possibly create a totally waterproof LAY OUT THE ROOF
roof system, can it? In a word: yes. In three words:
yes, of course. That’s what this book is about — an When laying out a roof in preparation for
ingenious roofing system made of natural materials slating, chalk lines across the entire roof area mark-
that will not leak if properly installed and main- ing the tops of each row of slate. No metal drip edges
tained. It’s the slate and the flashings that keep the are needed on slate roofs such as the aluminum drip
water out. The underlayment is the least important part edges popular on asphalt shingle roofs. The purpose
of a standard slate roof once the finished roof is installed. of these metal strips is to prevent the asphalt shin-
What about ice damming? Surely that’s a gles from sagging at the edge of the roof. Slates don’t
good reason to use a beefy underlayment. However, sag. These small “drip edges” are not the same as the
ice build-up along eaves is usually an insulation large, exposed, copper or stainless steel snow aprons
problem. Uninsulated roofs thaw the ice and snow installed at the eaves of roofs to eliminate ice
from the field of the roof and the water drains down damming. Snow aprons can function quite well on a
to the eaves where it freezes again, at times building slate roof.
up dangerous levels of ice. You can largely prevent When measuring for the starter slate and the
this by insulating the roof. You have leakage at the first row, allow for the slate to hang beyond the drip
eaves anyway? Think of it this way: If the leakage is edge of the fascia (or trim molding) one and a half
being caused by water penetration through the slates inches. The starter slates are usually made of the
due to ice back-up, then the water penetration same size slates as those on the main roof, turned
should occur along the entire length of the eaves. This sideways, and usually 1/4 of the length of the first
is not usually the case at all. If, in fact, that is what one is trimmed off to allow the joints to be properly
happens, more headlap may likely solve the problem staggered in relation to the overlapping row. All butt
(unless the problem is due to insufficient slope or joints between slates should have a minimum of three
other design flaw, in which case you’re beating a inches of lateral clearance in relation to the butt joints of
dead horse). In any case, water penetrating a slate overlapping slates (this is the sidelap already men-
roof anywhere, for any reason, means the roof was tioned). On many old roofs, the starter slates are not
not installed or designed properly or the slates or laid sideways, but are simply the same slates as the
flashing simply need repaired. When installing a rest of the roof — cut short — and again the joints
slate roof in an area known for ice damming prob- are staggered. In any case, make sure the starter
lems, install the bottom three or four feet of the roof slates have sufficient headlap (3” minimum) under
along the eaves with 4 inches of headlap rather than the course two rows above them.
the typical 3 inches and make sure the roof slope is In all cases, the starter slate must be laid
8:12 or greater. Architects must learn that slate roofs over a cant strip about 3/8” to 1/2” thick (for stan-
have certain design considerations that are different dard thickness slates), which cocks the slate at an
from other roofs — sufficient slope being one of angle comparable to the angle of the slates on the
them. The object is to create a waterproof roof, rest of the roof. The starter row is typically laid back
regardless of the underlayment. Underlayment side out so that the bevel of the starter slate meshes
material is only expected to have a relatively short with the bevel of the first row.
career on the roof. To depend on it for the proper A thicker cant strip is needed when using
The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 159
 All photos by author.

160 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 161
“RAGGED BUTT” SLATING — This roof in Lake Forest, IL, includes
a mix of Vermont gray-black, Virginia gray, Vermont “sea green,” and heavier slates. The purpose of the cant strip is to tilt
Vermont mottled purple slates (also shown below). the first row of slates at the same angle as the rest of
the roof, as no slate lays flat against the roof deck.
When using thicker slates, you can figure out the
thickness of the cant strip on-site by laying some
slates on top of each other with the proper headlap
and observing the gap beneath the bottom slates.
The slates that run up the side edge (rake) of
the roof should extend beyond the gable end one full
inch. Run a string up the edges of the roof to give
yourself a straight line to follow when laying the
slate (tie the string to temporary nails). Or, alterna-
tively, chalk a vertical line up the roof near the edge
to align the end slates.
When you reach the top of the roof, the top
two rows of slates must be cut shorter in length to fit
the roof. Sometimes the top row, the “cap” slates,
must be shimmed under their top edge so they’ll
remain flat when the ridge metal or ridge slate is
installed; otherwise they may cock crookedly and
look bad. They can be shimmed with pieces of slate,
usually the pieces that are cut off the top rows when
the slate is laid, or a strip of wood can be used.

STAGGERED AND RAGGED BUTT SLATING STYLES

HIPS
The roof slates are installed in the standard manner — the top
edges of the slates are chalked on the roof before installation, Many hips on old American slate roofs are
but the slates used are of varying lengths. If the chalk lines simply covered with metal ridge flashing, either gal-
are for 16” lengths, for example, 16” long slates are used as
vanized steel (known as “ridge iron”) or copper.
well as 18” and maybe 20” long slates. The extra length is left
to hang down in order to create a “staggered butt” look (oppo- These are simply nailed into place using nails of
site page). The exposed butts can also be irregularly cut to compatible metal (often 2.5” in length) spaced every
produce a “ragged butt” style as shown above.
All photos by author.
foot or two, and the nail heads are caulked with a

162 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

 Slate roofs can be multi-dimensional. They can include color variations, length variations, width variations, and thickness
variations, all of which can be combined to create a roof of inimitable beauty. The roof shown here, at Lake St. Catherine in
Vermont, exploits all four of these dimensions using a combination of Vermont slates of uncommon thickness.
Photos by author.

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 163

 Six Steps to Building a 150-Year Roof

1. Use a long-lasting roofing material such as slate. Make

sure the slate is top quality S1 grade. Never use fake substi-
tutes.
2. Use a long-lasting roof decking material such as natu-
ral rough-sawn lumber or kiln-dried, planed boards at least
3/4” thick. Avoid CCA treated lumber and any laminated mate-
rials such as plywood, particle board, or OSB.
3. Use copper or stainless steel nails to fasten the slate
or tile to the roof. A good grade of hot-dipped galvanized nail
will last 100 years or more, but not nearly as long as copper
or stainless steel nails, which will last indefinitely.
4. Use stainless steel flashing, such as terne-coated
stainless. Copper and lead flashings will last indefinitely if kept
painted, but can develop pitted holes in 60-70 years if unpaint-
ed, especially in valleys. No one yet knows how long terne-
coated stainless will last, but it will presumably outlast both
copper and lead. Alternatively, build rounded (slated) valleys
and eliminate the valley flashing, which is subject to the great-
est wear on the roof.
5. Design the roof properly. Use adequate slope — the
more the better (the roof should be too steep to walk on). The
lower the slope, the shorter the life of the roof. Build the roof
sturdy enough to prevent sag over the years.
6. Make sure the roof is installed by properly trained per-
sonnel who understand the nuances of traditional roofing and
who possess the proper tools and equipment. For example,
slate roofs should not be walked on during installation.

material such as clear silicon of lifetime durability. RIDGES

Hips made of slate are quite common and
usually require less maintenance than metal hips. Ridges are the horizontal peaks of the roof.
Common slate hips include the miter hip and the In the United States they are often made of metal,
saddle hip. Mitered hips simply consist of the cours- especially galvanized steel or copper. When finish-
es of roof slates butted against each other at the hip. ing slating along a ridge, it’s important that the roof
Mitered hips sometimes utilize step flashings under boards do not have any appreciable gap at the peak.
the hip slates. If a gap exists (as is typically left when a carpenter
Saddle hips are made of slates positioned sheaths a roof for ventilated ridge) the slates may
parallel to the hip rafter and laid over the standard not lay properly and the ridge metal will not have a
field roof slates. Saddle hips can also have flashing sufficient base on which to nail.
underneath them, either a continuous piece or step Alternatively, ridge vents designed specifi-
flashing. Flashing under the hip slates reinforces the cally for slate roofs are commercially available.
hips and is helpful in preventing leakage at the hip These require that a gap be left at the peak of the
when the roof ages, since the hip slates tend to sepa- roof between the sheathing boards. Follow the
rate somewhat after eighty or ninety years. instructions from the manufacturer when installing
Nevertheless, flashing under hip slates is uncom- these ridges (see back of book for sources).
mon on older roofs and most were installed with no The Welsh are quite fond of lead ridges, gen-
flashing at all. erally unavailable in the United States, but certain-
Ridge metal can be installed over old, sepa- ly superior to galvanized steel ridge. Copper ridge is
rated hips to cover any gaps or tarred joints. readily available in the U.S., either custom made or
prefabricated from roofing supply outlets.
Slate ridges are quite common in the U.S.
Europeans often use ceramic tile ridges on their
slate roofs, as can be seen throughout this book;
these ridges are perhaps the most durable of all.
They’re more compatible with the masonry-walled
construction of Great Britain, but they’re rare in the
United States.

164 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

 SIMPLE INSTALLATION SEQUENCE

1. Install 30 lb. felt over the board decking; chalk lines to mark the top edge
of each slate course. 2. Install cant strip, starter course, and begin slating. 3.
Periodically leave out a slate in order to install a roof jack. 4. Stage the roof
with adequate planking. 5. When the roof has been slated, remove roof plat-
forms and install slates where missing using stainless steel slate hooks.

overlap
side edges
6” and top
edges 3”

SHAPES OF ROOF SLATES: Roof slates were once routinely manufactured in decorative shapes in order to add an elegant appearance
to the roof. Today’s roof slates are mostly manufactured in a rectangular shape (above right), however they can still be ordered from some
suppliers with decorative shapes, or they can be cut to match the patterns of old roofs using a hand cutter.

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 165

 RIDGES and HIPS
(Adapted from Slate Roofs (1926), author unknown, p. 16-17, 19)

166 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

Above left: Lead ridge common in Great Britain, here shown in Devon, England. Above right: Copper ridge in Massachusetts by Doug
Raboin. Below left: Lead hips and valleys plus ornate ridges on this slate roof in Worcester, England, demonstrate the use of durable
materials to finish off a roof. Below right: Smithsonian Institution Building with Buckingham slate ridge installed with exposed nails.

Photo credits: top left by Dave Starkie, top right by Doug Raboin, bottom left by Dave Starkie, bottom right by author.

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 167

 WHAT NOT TO DO WHEN INSTALLING A SLATE ROOF
1. Do not use laminated wood roof decking — use solid lumber.
2. Do not use insufficient headlap — use three inches of headlap — more on lower slopes or ice dam prone areas. Use a
minimum of 3” of lateral spacing (sidelaps).
3. Do not routinely walk on the slates or sit on them carelessly during installation — if possible, work from the side or from
hook ladders or on planks. Walking on slate roofs during installation is one of the most common causes of breakage and
subsequent failure with new slate roofs.
4. Do not use “electrogalvanized” nails for slate — use copper or stainless steel nails on new installations and hot dipped
galvanized nails, or better, on recycled roofs. When doing restoration work, use nails similar to those already existing on
the roof.
5. Do not rely on the underlayment to permanently waterproof the roof — you will puncture it profusely when you install the
slate. A properly installed slate roof will not leak, underlayment or no underlayment.
6. Do not use aluminum drip edges — they’re made for asphalt shingle roofs. These are not the same as copper or stainless
steel aprons installed at the eaves of roofs to eliminate ice damming.
7. Do not use ventilated ridges unless they’re specifically designed for slate roofs — if possible, ventilate through gable ends
or through individual roof vents.
8. Never install slates with felt paper overlapping each course. Install the felt under the slate.
9. Do not select a slate based only on how it looks when new. Choose a good quality rock that has a history of successful
use as a roofing material. The following quote from a misled home-owner reveals a situation that you want to avoid at all
costs:

“We built a new home here [Florida] last year and put a slate roof on it. When we specified black slate our general contractor obtained sam-
ples from various suppliers and we chose the one that was the blackest. It was offered by [Company X] Slate, Inc., and was represented to
be ASTM S1 and domestically mined. It was put on in June 1996, and by August it had large, red rust spots all over it. It got much worse
very rapidly, and every time it rains, it leaks rust down on my white stone entrance, walks, etc. When we investigated, it turns out the slate
was shipped from overseas and had large amounts of pyrite. Independent testing revealed a modulus of rupture and an absorption rate that
were both so poor as to not even rate this slate as an S3! The slate company is now expected to replace the entire roof, and the threat of
litigation is coming up repeatedly.”

10. When ordering roof slates, make sure standard thickness (3/16” to 1/4”) slates have nail holes that are punched rather
than drilled, or if drilled, also counter-sunk. The nail head must be able to sit down into a counter-sunk depression in order
to avoid rubbing on the overlying slate and working a hole in it. This is not such an issue with 1/2 inch or thicker slates.

GRADUATED SLATE ROOFS more water than any other part and heavier slates
are more apt to withstand the excess erosion and
Roof slate is available in many types with weathering that occurs near the drip edge.
many different characteristics. In the old days, when As the roof installer progresses up the roof,
roofing stone was wrestled from deep quarry holes smaller and smaller slates are used, with the small-
and dark mines using hand tools and beasts of bur- est slates, perhaps only 12” long, fastened near the
den, the splitting of roofing shingles from rock was top. The result is a roof that “graduates” in size from
an arduous and exacting art. Some European slate large at the bottom to small at the top, yielding an
veins contained very hard, rough-textured rock stra- architectural style that is utterly unique and quite
ta that could not easily be split into the uniform, pleasing to the eye. Traditional graduated roofs also
thin sheets required for shingles. For the sake of effi- utilize random width slates. There are still many of
ciency, the stone was split into the largest slate shin- these roofs in good condition scattered throughout
gles possible, creating a supply of coarse shingles the United States and Europe, yet the art of
that varied considerably in size — some larger, some installing graduated slate roofs is a disappearing
smaller. In order to make good use of all of these one.
slates, a certain style of roof was developed of neces- A good place to look at the long history of
sity — graduated slate roofs. graduated slate roofs is in Scotland, England and
In this style of roofing, the largest stones, Wales. Scottish slate tends to be a rugged, coarse,
sometimes massive, are installed at the bottom of and extremely durable material. Unable to split
the roof. This allows for the heavier weight of these large, uniformly thin slates from the raw material
large slates, perhaps 30” long and an inch thick, to available in Scotland, the Scots created a distinctive
be carried by the wall of the building. It also relieves roofing style with a rough texture in keeping with
the roofer of having to lug the flat stones, which may the stone architecture so characteristic of Scotland's
weigh 200 pounds, to the very top of the roof. traditional buildings. This graduated slating style
Furthermore, the bottom of the roof is exposed to was also popular in England and Wales for the same

168 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

 t A GOOD EXAMPLE OF BAD WORKMANSHIP t Roof jacks and planks (below) make a handy and safe platform
from which to work when installing a new slate roof.
Poor sidelap technique ruined a slate installation
(below) on a bad “economy method” re-installation of
what started out to be an excellent slate roof.

Curved eaves may require shorter pieces of slate to be used at the eaves
curve — the sharper the curve, the shorter the slate. Broken slates are
repaired in the same manner as any other slate on the roof — with a nail and
bib or a slate hook. Large gaps underneath the slates where the curvature
occurs may benefit from horizontal battens, which help in nailing the slates
to the roof by providing additional bite for nails. The battens also provide
some backing support for the slates.

MITERED HIPS on a
90-year-old Vermont
purple slate roof, in
Grove City, PA, are
being covered with
new metal ridge. The
hips had opened
enough over the years
to cause slight leaking,
and therefore had to
be covered. Copper
ridge is excellent for
this purpose.

Photos this page by author.

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 169

Beau and Liz Heath Residence; Grove Ketler House; Grove City, PA; 3” headlaps; Ketler Garage, 25’ 8” from drip edge to ridge;
City, PA; 30’ rafter, 3” headlaps; VT slates. VT slates 39 courses; 3” headlaps; VT slates
Unusual graduated slate roof with uniform
standard thickness slate. # courses length of slate # courses length of slate
[Top of Roof] [Top of Roof]
# courses length of slate etc. 9 . . . . . . . . . . . . . . .13”
[Top of Roof] 1 . . . . . . . . . . . . . . .27” 1 . . . . . . . . . . . . . . .14”
13 . . . . . . . . . . . . . .16” 1 . . . . . . . . . . . . . . .28” 6 . . . . . . . . . . . . . . .18”
11 . . . . . . . . . . . . . .18” 1 . . . . . . . . . . . . . . .29” 3 . . . . . . . . . . . . . . .17”
9 . . . . . . . . . . . . . . .20” 1 . . . . . . . . . . . . . . .30” 5 . . . . . . . . . . . . . . .16”
6 . . . . . . . . . . . . . . .22” [Bottom of roof] 3 . . . . . . . . . . . . . . .19”
5 . . . . . . . . . . . . . . .24” 3 . . . . . . . . . . . . . . .20”
[Bottom of roof] 3 . . . . . . . . . . . . . . .21”
3 . . . . . . . . . . . . . . .22”
3 . . . . . . . . . . . . . . .24”
[Bottom of roof]
This 90-year-old roof had five slate lengths
which graduate in 2” increments according to This 90-year-old roof graduates one inch
an apparently random scheme. The slates per course from bottom to top. The bottom This 90-year-old roof graduates randomly. The
on this roof are 1/4” in thickness. slates are 1” thick, the top slates are 3/16”. bottom slates are 1” thick, top slates are 3/16”.

FIVE EXAMPLES OF GRADUATED SLATE ROOFS (ABOVE AND OPPOSITE PAGE)

It’s obvious that the sizes of slates and number of graduations are a matter of style and/or personal taste.
Photos by author.

reason — it allowed for the efficient use of a stub- practice of using hand split lath, as mentioned earli-
born material. er, and continues to this day as much from tradition
On one of the author’s trips to Wales as from a lack of lumber resources in England and
researching slate, he happened to meet a young Wales.
slater who was installing a slate roof. Interestingly, But another surprising practice was the sort-
there were several steps involved in the slate instal- ing of the slate prior to installation. This was a roof
lation that roofers in the U.S. almost never of uniform sized slates — not a graduated slate roof.
encounter. For one, the roofer was obligated to Yet, the roofer, according to custom, sorted the slates
“hole” each slate, as no nail holes are punched in the according to thickness before carrying them up onto
slate at the quarry as is typically done in the U.S. the roof, the thicknesses being termed “very heav-
This is a carry-over of the days when graduated slate ies,” “heavies,” “mediums,” and “lights.” The very
roofs were the norm and nail holes had to be heavies were installed at the bottom of the roof, and
punched in the slate on the job after the proper over- so on until the lights finished off the top. I found the
lap had been determined for each diminishing variance in thicknesses to be minimal, yet the roofer,
course. The position of the holes in the slate was par- with tradition in his blood, carried on a custom that
ticularly critical when using lath, which left little began with the graduated roofs of old: sorting prior
room for error. Sawn lath strips developed from the to installing.

170 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

Glenridge Hall; Sandy Springs, GA; 3” Harbison Chapel, Grove City College, Grove slates with random widths is an
headlaps; mixed VT slates City, PA — 32’ from drip edge to ridge; 55
courses; 3” headlaps; VT mixed slates art in itself, as adequate sidelaps
# courses length of slate must be carefully maintained.
[Top of Roof] # courses length of slate That is to say that the side-butts
18 . . . . . . . . . . . . . .14” [Top of Roof]
19 . . . . . . . . . . . . . .16” 16 . . . . . . . . . . . . . .12” (where the slates butt against
24 . . . . . . . . . . . . . .18” 14 . . . . . . . . . . . . . .14” each other at their sides) of each
8 . . . . . . . . . . . . . . .20” 4 . . . . . . . . . . . . . . .16”
5 . . . . . . . . . . . . . . .22” 8 . . . . . . . . . . . . . . .18”
pair of slates should be spaced
4 . . . . . . . . . . . . . . .24” 4 . . . . . . . . . . . . . . .20” three inches laterally from any
[Bottom of roof] 5 . . . . . . . . . . . . . . .22” side-butt above or below. If the
4 . . . . . . . . . . . . . . .24”
[Bottom of roof] side-butts are spaced too closely
to each other, the roof could leak.
A sloppy roofer will install ran-
This newly re-installed roof graduates ran- This 75-year-old roof graduates randomly. The dom width slates with close side-
domly. The bottom slates are 1” thick, the bottom slates are 1-1.5” thick, the top slates are butts; a master roofer will not.
top slates are 3/16” thick. 3/8-3/4” thick.
Finally, a graduated slate
roof can be made a work of art by
blending together a variety of
slate colors. A common color
scheme involves a mix of
Vermont slates, including pur-
ples, unfading greens, sea greens,
grays, and perhaps Vermont
black, and/or New York red.
Sometimes Pennsylvania blacks,
Virginia grays, or European,
Chinese, or other imported slates
are mixed in as well. The per-
centage of each color must be
determined before the slate is
ordered, and with a variety of
lengths, widths, and thicknesses
also to consider, careful pre-plan-
ning is a necessity in order to
Today, the sorting of the slate prior to and ensure a successful job when creating a graduated
during installation is critical to the successful cre- slate roof. Some suggested color combinations by
ation of a graduated slate roof. It requires careful Rising and Nelson Slate Co. include: 1) 70% semi-
advance planning for the job to be well done. The weathering gray green with 30% variegated purple;
number of courses required on the roof must be 2) 50% semi-weathering gray green and 50% varie-
determined beforehand, and the number and degree gated purple; 3) 60% unfading mottled green and
of graduations, both in thickness and length, must gray with 40% unfading green; 4) 50% semi weath-
also be part of the planning of the roof installation. ering gray green with 20% variegated purple, 20%
There is no one correct formula for this. unfading green and 10% Vermont gray black; 5) 70%
Diminishing lengths can occur with each course, or unfading green and 30% unfading mottled green
they can occur only with every several courses. In and purple.
any case, once the particular formula for a particu- Once completed, a new graduated slate roof
lar roof job has been determined, then the correctly can be expected to grace a building and charm a
sized slates can be ordered from the quarry. To pro- community for at least a century, and maybe two.
vide examples, the measurements of the graduations
of five random graduated slate roofs are illustrated
above.
Graduated slate roofs utilize slates of vary-
ing lengths, typically with varying thicknesses, as
well as slates of random widths. The installation of

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 171

172 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs
 EYEBROW DORMERS

Perhaps one of the most elegant of slate roof installation

techniques is the eyebrow dormer. In the illustration at the top of
this page, the 120-year-old Peach Bottom slates (in perfect condi-
tion) on the field of this roof in St. Louis, Missouri, USA, are 10”
wide, but the slates that curve over the dormer are 5” wide, allowing
them to sweep across the dormer in a smooth arc.
Above, an eyebrow dormer on Glenridge Hall in Sandy
Springs, Georgia, is stripped of its slates in preparation for reslating
revealing the sheathing pattern underneath. Slated dormer is shown
at right. 20 ounce overlapping copper strips, 16” deep, fortify the
curved sections.
Opposite page, top right: There is a sheet of zinc flashing
underneath each course of 5” slates shown in the photo where a
slate has been pushed aside to reveal the hidden flashing.
Opposite page, top left: This eyebrow dormer in New
Jersey on the Zimmerman Estate is made of 120-year-old Vermont
sea green slates.
Opposite page, bottom: An eyebrow dormer in Grove City,
Pennsylvania, USA, at the Ketler Estate, made of a mix of Vermont
slates installed in a graduated pattern.

The two Glenridge Hall photos are by Ron Stokes. Remaining photos by author.

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 173

 ROUNDED AND CONICAL TURRETS AND TOWERS

The photos on this page are of a 120-year-old Peach Bottom

region slate roof located near St. Louis, Missouri, USA. The
slates are nailed to the roof with iron nails. Note how the
slates are installed in narrow pieces in order to conform to the
curved shape of the turrets. Vary narrow slates are nailed on
with only one nail. Flashing is not needed between the cours-
es of slates due to the extreme slope of the roof. The photos
on the opposite page showing the rafter framework are of the
towers below.
Photos by author.

174 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

s Note the horizontal framing members between the rafters.
The narrow sheathing strips are installed vertically (parallel to
the rafters) and nailed or screwed to these curved framing
members.

The tower at right is covered with 120-year-old Vermont

unfading green slate in excellent condition.

The illustration below indicates that the slates’ sides may

need to be slightly tapered in order to lay well on the roof.
2
Surface area of a cone= (3.1416D X S/2) + .7854D
when D is the diameter of the base and S is the slant height

Photos by author.

The Slate Roof Bible — Chapter 13 — Installing Slate Roofs 175

 ALL IN A PENNSYLVANIA DAY’S WORK
1. A typical American low-slope particle board and asphalt
roof on a newly purchased structure proves unacceptable to
the new owner. 2. Hemlock 2x8 rough-sawn rafters are cut a
day ahead to prepare for the construction of a 12:12 sloped
recycled-slate roof. 3. A volunteer community group arrives,
tears off the old roof, and begins installing the new rafters.
Note the stickered rough-sawn hemlock roof sheathing in
foreground. 4. The 1” hemlock sheathing is nailed over the
rafters then covered by 30 lb. felt paper. Note the toe-holds
(spaces) left between the sheathing boards, visible on the
back side. The old roof was removed and the new roof was
framed, sheathed, and papered in a day. 5. The slates are
installed, one side at a time. Each side requires a day’s hard
work by two experienced slaters. 6&7. The finished roof,
made of three different recycled Vermont slates and copper
ridge, will last the life of the owner and many years more.
Photos by author.

176 The Slate Roof Bible — Chapter 13 — Installing Slate Roofs

 Chapter Fourteen

TRADITIONAL EUROPEAN SLATING METHODS

T
his section is not meant to be a com- It was modified over the years, however, so
prehensive explanation of interna- that the slates were eventually nailed into the lath —
tional slating styles and methods. the lath itself is no longer split, but sawed into
Instead, it is only an introduction, as a thorough approximately one inch by two inch strips. Felt
look at such techniques would require another vol- paper is installed under the lath where it drapes
ume. For more information about the various coun- between the roof rafters, waiting to catch a leak
tries mentioned below, please refer to Chapter 10 — should one occur. The advantage to felting under the
International Slate. lath is that the roof nails do not penetrate the felt.
When a roof of this style gets old enough to require
BRITISH ISLES replacement, the old slates are carefully removed,
the lath and felt are replaced with new material,
As stated earlier in this book, the Welsh and then the roof is reslated, either with new slates or
British originally hung their slate on split wooden old.
lath using wooden pegs as hangers. The pencil-stub- The slates are sorted by thickness before
sized pegs were split out of a block of wood, then being nailed to the roof. The “very heavies” are
driven through a round hole that had been punched placed at the bottom of the roof, the “heavies” above
or drilled into the top center of the slate or stone. them, the “mediums” above the heavies, and the
This force-fitting caused the peg to be firmly wedged “lights” at the top. Unlike American slates, Welsh
in the slate. The peg hung over a thin lath while the slates don’t come pre-punched for nail holes from
weight of the stones held the roof together. This sys- the quarry, but instead must be “holed” by the roofer
tem worked very well and lasted quite a long time. prior to installation.

SCOTTISH SLATE ROOF

Photo by author.

The Slate Roof Bible — Chapter 14 — European Slating Methods 177

 PEGGED SLATES ON LATH
note the “shouldering” of the slates
(top corners rounded off)

Illustration at right used with permission from stoneroof.org.uk, Terry Hughes, Slate & Stone Consultants, Ceunant, Caernarfon, Gwynedd LL55 4SA UK

Another technique exhibited on European standard American slate. Traditional Italian roofs
slate roofs is “weather-clipping” (illustrated in this are sometimes installed with a low slope, as is also
chapter) — cutting the corner off the bottom of the common on old roofs in Spain and elsewhere. The
slates at the gable ends of the roof (known as the reduction in drainage caused by a lower slope is off-
“gable verge” in the UK). The purpose of this prac- set by a slating method known as “triple-covering”
tice is to draw the rain water toward the center of the in which the head lap extends completely down to
roof as it runs down the “verge,” or the outer edge of the top of the third slate below, effectively creating a
the roof. triple layer of slate over the entire roof. Today,
Italian slates are hung on stainless steel slate hooks.
SCOTLAND Modern slating methods in Italy include
numerous styles, although the slate tends to be
Scottish slates tend to have a more rugged installed thick and hung on hooks, or occasionally
character and texture than Welsh slates and Scottish nailed. Some of the styles include the “French”
slating techniques developed their own unique char- method, “triple covering,” and standard lap slates of
acteristics as a result. Traditional Scottish slating various shapes.
tends to utilize random width slates laid in a gradu-
ated pattern. The top corners of the slates are SPAIN
“shouldered,” allowing the rough slates to be more
easily installed and, if necessary, replaced. Scottish Traditional Spanish slating involves the use
slates are head-nailed, utilizing a single nail located of un-trimmed slates laid in a random pattern. The
at the top center of the slate. Perhaps the most obvi- slate is so haphazard in its appearance that it looks
ous difference between Scottish slating styles and like a work of art. This is in stark contrast to modern
British is the use of solid board roof sheathing by the slating methods being taught in Spain’s roofing
Scots (referred to as “sarking” board), instead of the schools today, which insist upon installing all slates
battens or lath preferred by the British and Welsh. in a uniform manner with standard thicknesses
using only slate hooks. The trend to install roof
ITALY slates with slate hooks rather than nails is a domi-
nant one in much of today’s European roofing cir-
Italian slates tend to be high in carbonate cles. Slates installed with hooks can be thinner,
and although black when quarried, will turn almost therefore yielding more shingles per block of slate
white with exposure to the weather. Although high quarried. Thinner slates, however, may not last as
carbonates are usually considered to be a weakness long, so those who are intent upon constructing
in roofing slates, this problem is offset in Italy by roofs that will last a century or two tend to stick with
splitting the slates to a thickness of about a half traditional methods by using thicker slates and nail-
inch, which is fully twice as thick or more than a ing them into place. Hooks work well for fastening

178 The Slate Roof Bible — Chapter 14 — European Slating Methods

slates, especially stainless steel hooks, but tradition- the UK and other parts of Europe. The result is a
alists find that the glint of exposed steel across the totally unique style of slating that enables the roofer
roof in the sunlight detracts from the beauty of the to dispense with much of the exposed flashing metal
stone roof. common to American roofs and instead simply wrap
The Spanish are the world’s greatest slate the slates over the valleys and dormers in a smooth,
producers with a reputation for quality, integrity, sweeping style that is both artistic and functional.
and craftsmanship in the production of roofing Needless to say, German slating techniques require
slate. Spanish slate is prized in Europe and increas- specific training and time to master, which is per-
ingly sought after in America. Roofing schools in haps why they are not more widespread throughout
Spain teach many methods and styles of slate roof the world when compared to the much easier, sim-
installation. Although our focus here is on the older pler, but less exotic system of standard lap rectangu-
traditional methods, this is not to suggest that tradi- lar slating. With 1,700 years of tradition behind
tional slating is all that is done in Spain. Many mod- them dating back to the Romans, the Germans have
ern slate roofs patterned after the UK style of slating kept alive and perfected a unique style of slating
with rectangular slates on battens, hung with either that is incredible and beautiful. A thorough discus-
hooks or nails, are a common sight in Spain today. sion of German slating techniques would require a
book unto itself. Nevertheless, this pictorial intro-
GERMANY duction should give the reader a good idea of the
nature and uniqueness of Germany’s slating tradi-
Although trained German slaters are tions.
undoubtedly capable of any sort of slating style,
their traditional methods are quite unique, which is EUROPEAN ROOFING SCHOOLS
what most sets the Germans apart from the rest of
the world in the realm of slate roofing. “Altdeutsche” Roofing is a serious and respected trade in
or Old German slating and its very similar modern Europe, perhaps because the roofs there tend to be
cousin, Shuppen (fish scale) slating are unheard of in high quality and long-lasting. In contrast, average
the United States, although such roofs can be seen American roofs are often marveled at if they last
throughout Europe outside of Germany, wherever more than twenty years, and American roofers are
German slaters display their incredible craft. Of often placed in a category on the social totem pole
course, traditional German slate roofs are seen slightly above “ex-convict.” The people who learn
throughout Germany, too. the roofing trades in Germany are expected to
The slating style is unique in that the slate is undergo a three-year period of formal training fol-
cut in the shape of a parallelogram rather than a rec- lowed by field experience, then perhaps an addition-
tangle, then laid on the roof with one side edge and al training for those who will be the “masters.”
top edge overlapped in such a manner that only one European roofing schools cover slate roof installa-
corner is exposed. This corner is cut into a curved tion methods — modern ones as well as traditional
shape, usually by hand using a slater’s hammer and ones that may be specific to the country where the
stake right on the job site as in the Altdeutsche school is located (such as German traditional slating
method, where the slates will vary in size, or manu- methods being taught in German roofing schools).
factured as such in the Shuppen method where the The roofing schools may also cover ceramic tile roof
slates are uniform in size. Each piece of roofing slate installations, artificial slate, metal, and even low-
is nailed in place with three nails onto a solid board slope, single-ply roof systems.
roof deck rather than the lath roofs more common in

The Slate Roof Bible — Chapter 14 — European Slating Methods 179

 COMMON SLATING METHOD IN
ENGLAND AND WALES

At left are exposed rafters on an

old Welsh slate roof. The old slates
and lath have been removed by
Robert Jones and David Hussey in
preparation for re-roofing.

The roofing felt is installed directly

over the rafters.

The slating lath is nailed to the

rafters directly over the felt paper.
The slates are then nailed to the
lath using two nails positioned
about a third of the way from the
top of each slate and about an
inch or inch and a half in from the
edges.
Photos by author.

INTERNATIONAL FEDERATION
FOR THE ROOFING TRADES
(IFD):

Internationale Foderation des

Dachdeckerhandwerks e.V.,
Fritz-Reuter-Str.1, D-50968 Koln,
Germany; Tel: +0049-221 3980380;
Fax: ++49-221 39803899;
email:info@ifd-cologne.de
www.ifd-cologne.de

180 The Slate Roof Bible — Chapter 14 — European Slating Methods

s Twenty-seven-year-old Neil Berridge, with ten years of slating experience under his belt, prepares this new life-boat
shed in Barmouth, Wales, for slate. The roof is papered directly over the rafters and the slating lath is installed over the
felt paper, as is common in England and Wales. The slates have been sorted into “very heavies,” “heavies,” “mediums,”
and “lights,” depending on thickness — the heavier ones are nailed to the bottom of the roof. The slates have also been
“holed” by Neil (nail holes punched).

t The finished roof is shown below.

Photos by author.

The Slate Roof Bible — Chapter 14 — European Slating Methods 181

 Two very old, low-slope Italian slate roofs during a rain.
Photos by author.

182 The Slate Roof Bible — Chapter 14 — European Slating Methods

 s The underside of the roof on the opposite page, top.

t “Triple-covering” on the same Italian roof: The bottom of each slate extends down to the top of the third slate beneath it.

Photos by author.

The Slate Roof Bible — Chapter 14 — European Slating Methods 183

 Old slate roofs in the mountainous Orense region of Spain where much of Spain’s roof slate is quarried.

Photos by author.

184 The Slate Roof Bible — Chapter 14 — European Slating Methods

s Traditional Spanish slate roofs, such as on the slate quarry building above, are as much art as they are functional.

t A traditional Spanish slate roof being prepared for installation is inspected by Mr. Vime
and Ms. Pilar Cubelos of the Franvisa slate company in northwest Spain.

Photos by author.

The Slate Roof Bible — Chapter 14 — European Slating Methods 185

 Photos both pages by author.

186 The Slate Roof Bible — Chapter 14 — European Slating Methods

The Slate Roof Bible — Chapter 14 — European Slating Methods 187
188 The Slate Roof Bible — Chapter 14 — European Slating Methods
The roofing school in Mayen, Germany (opposite page), allows students to learn every aspect of German slating techniques, as well as metal
work, tile roofing, and even wall cladding with slate. A student in the same school (below) works out the details of Altdeutsche slating. Another
German roofing school in the Fredeburg area (above) is also fully populated with highly motivated young men. Photos by author.

The Slate Roof Bible — Chapter 14 — European Slating Methods 189

Slate wall cladding at the Rathscheck Company, Germany’s largest slate merchant.
 Chapter Fifteen

ROOF INSCRIPTIONS AND DESIGNS

O
ne of the interesting characteristics matter of referring closely to the schematic during
of slate roofs is that they can be installation while using slates of contrasting colors
installed in decorative styles using in order to make the design appear on the roof. This
slates of various colors. These decorative roofs can does not add a lot of time to the job, but does create
be inscribed with installation dates or with words, a lifetime landmark roof.
names, or abstract designs. In any case, the easiest
procedure to use when installing an inscription or
design on a slate roof is to draw a schematic of the
roof beforehand. Make sure the schematic shows
every slate in its proper proportion. The dimensions
of the roof as well as the size of the slates must be
known in order to do this — a job made easier by the
use of a computer, although a computer was obvi-
ously not available in the 1800s when many dates
were installed on slate roofs. Once the schematic has
been created and a number of copies made, the artist
can play around with various designs until he or she
Potential shapes of roofing slates, from a 1905 booklet
has settled on one that looks good. Then it is only a called “The Slate Roofer.”

s Hathaway barn, near Rutland Town, Vermont.

Opposite page: Intricate slate wall cladding at Rathscheck Slate Company in Mayen, Germany.
Photos by author.

The Slate Roof Bible — Chapter 15 — Inscriptions and Designs 191

 s NY Red slate against a Vermont sea green background on a barn in northwestern Pennsylvania reads
“P. E. Wood Fountain Farm 1900.”

t Vermont unfading green slate accents a Cwt-y-Bugail Welsh black slate background on the Cathedral of St. Andrew in Little Rock,
Arkansas, USA (below). See additional photos on pages 195, 228 and 229.

Photos by author.

192 The Slate Roof Bible — Chapter 15 — Inscriptions and Designs

Decorative artwork blends with skilled craftsmanship as
indicated by the figure emerging from the wall (right), cre-
ated in a German roofing school. The snail-like figure (bot-
tom) was worked into a slate roof being installed at the
World Slating and Tiling Championships, 2002, in Dublin,
Ireland. The Belgium team created this artistic roof using
a sheet metal pattern that swiveled on a nail hinge
(below).
Photos by author.

The Slate Roof Bible — Chapter 15 — Inscriptions and Designs 193

194 The Slate Roof Bible — Chapter 15 — Inscriptions and Designs
 The schematic at left was used for the roof inscription above. Slates
are 12x22 sea green background (salvaged) with new 12x22
Pennsylvania black slates, donated by Williams and Sons Slate and
Tile in Wind Gap, PA. The building is a student-designed barn at the
Macoskey Center for Sustainable Systems Research and
Education at Slippery Rock University, Slippery Rock, PA, also
known as the Harmony Homestead, located on Harmony Road.

Photo above by author.

Right: Aerial view of the Cathedral of St. Andrew

in Little Rock, Arkansas, USA, re-slated in 2002-
2003 by Midland Engineering Co. of South
Bend, Indiana. Slate is Welsh black and
Vermont unfading green supplied by Hilltop
Slate Co. of Middle Granville, NY. The original
roof was approximately 125 years old at the
time of replacement. Flashings used on this
project were primarily terne coated stainless
steel.
Photo at right by Lyle Bandurski.

Opposite page: Amazing slate work done at the

German roofing school in Mayen, Germany.
Photos on opposite page by author.

The Slate Roof Bible — Chapter 15 — Inscriptions and Designs 195

196 The Slate Roof Bible — Chapter 15 — Inscriptions and Designs
s Apartment house near Monkton, Vermont reads “Oct 1884 N. J. Allen.” Bottom, this page: Date inscribed on a barn near Charlotte, Vermont,
probably reads “B” for the initial of the family name, and “1893.”

Opposite Page — Top: Purple slated barn near Brandon, Vermont with green slate date. Bottom: Two types of recycled roofing slates allowed
the owners in Plain Grove, PA, to create an interesting design on their garage roof. A blank schematic was drawn on a piece of paper before-
hand, then copied to allow for several designs to be considered. The final pattern, a Vermont purple slate on a Vermont sea green background,
has created a landmark roof. Middle right: Front side of a companion garage built beside the other garage in Plain Grove, PA and roofed in a
matching pattern. Middle left: Back side of the companion garage with date.

Photos both pages by author.

The Slate Roof Bible — Chapter 15 — Inscriptions and Designs 197

s New house near Castleton, Vermont.
t New cottage near Charlotte, Vermont. Harriet reserves the
right to change the “S” to “D” if Richard doesn’t behave.
Photos by author.

198 The Slate Roof Bible — Chapter 15 — Inscriptions and Designs

 s Dean brothers farm near Brandon, Vermont. Dean family mem-
bers had their names memorialized in the slate roofs of the farm.
t: What’s left of the inscription that read “Otter Creek Stock Farm
1911” near Whiting, Vermont.
Photos by author.

The Slate Roof Bible — Chapter 15 — Inscriptions and Designs 199

 s Smid building near Brandon, Vermont,
built and roofed by Chuck Smid, owner of
The New England Slate Company.

t Old barn in Granville, NY is a perfect

example of how any business owner can
create a beautiful and permanent sign by
using roofing slate on a wall or a roof!
Photos by author.

200 The Slate Roof Bible — Chapter 15 — Inscriptions and Designs

Sample lettering schematics published in a 1905 booklet called “The Slate Roofer” by Auld and Conger Co., Cleveland, Ohio. Each letter
requires the following number of slates: A-36; B-38; C-29; D-41; E-37; F-31; G-32; H-44; I-21; J-26; K-38; L-27; M-51; N-43; O-40; P-32; Q-43;
R-39; S-33; T-31; U-34; V-31; W-50; X-39; Y-33; Z-36; “1”-20; “2”-27; “3”-28; “4”-29; “5”-27; “6”-30; “7”-23; “8”-32; “9”-30. (Special thanks to the
folks at Vermont Structural Slate Company). Below left: Slate designs on the Slate Valley Museum roof in Granville, NY. Below right: roof design
on a residence in Whiting, New York. Photos by author.

The Slate Roof Bible — Chapter 15 — Inscriptions and Designs 201

 Chapter Sixteen

RECYCLING SLATE ROOFS

O
ne of the unfortunate consequences there than after they’ve been nailed onto another
of America’s throw-away mentality roof later. Some slates will develop hairline cracks or
is the loss of thousands of perfectly other flaws and must be discarded. A good slater can
good slate roofs, which are ripped off and destroyed tell a bad slate by simply holding it in his hand and
by uncaring roofers who can’t be bothered with recy- tapping it. A bad slate will give a dull thud, a good
cling anything. The slates are dumped in landfills slate will ring. When removing slates from an old
and the roof replaced with disposable petro-chemi- roof, it’s better to pry each nail loose than it is to pull
cal roofing which is also destined to soon clog a the nails through the slates. Prying the nails out pre-
landfill. Most of the harder slate roofs are quite recy- serves the old nail holes, while pulling the nails
clable, however, and care should be taken when through the slates ruins the holes which must then
removing them, to salvage the slates either for slate be re-punched with a slate hammer before the slate
roof repairs or for a completely new roof. can be nailed to another roof, unless the slate is used
The slates should be pried loose with a flat for repairs where the original nail holes may not be
pry bar (“wonderbar”) starting at the top of the roof, used at all.
and then allowed to slide down the roof and collect Recycling slate roofs is a good way to get an
on planks that run across the bottom of the roof on excellent roof for a new building with a unique
roof jacks. While someone is prying the slates loose, antique look that could last a century. Often the
someone else can be gathering them up and either recycled slates from one building don’t yield enough
carrying them down a ladder, dropping them down quantity to cover another entire roof, and recycled
over the eaves or through a hole in the roof in a rope slates from two or more roofs must then be collected
and harness, or sliding them down a chute to some- before a sufficient quantity is obtained for the job.
one else. Ideally, they would be slid directly into the When this situation occurs, it is imperative to “shuf-
back of a waiting truck where they’d be carefully fle” the slates together before nailing them onto the
stacked on edge before transit. new roof, as each old roof over time has developed
Salvaging roof slate can be a dangerous job its own weathered appearance, and in order for the
not only because of the heights involved, but also recycled slate roof to look right the slates must be
because the old buildings can be in poor repair and randomly mixed. For example, if you remove a thou-
may have rotten spots in the sheathing that can col- sand slates from old roof “A,” and five hundred from
lapse under the weight of a person. Furthermore, old roof “B,” and you need fifteen hundred for the
when the slates are slid down the roof, great care new roof you’re going to install, then for every two
must be taken to ensure that they do not slide under- “A” slates you carry up onto the new roof, you must
neath the plank that is supposed to catch them. carry up one “B” slate. If you can carry twelve slates
Otherwise, the falling slates can pose a grave hazard up a ladder at a time by hand, then eight of them
to anyone on the ground. It is advisable to lay 2x10 should be “A” slates and four of them “B” slates. This
planks on roof jacks, then catch the first slates that is how slates can be easily “shuffled” in order to
come sliding down the roof and carefully position make the job look right.
them flat on the planks so they will prevent the other Rather than shuffle two different batches of
slates from sliding under the planks. Finally, slate slates together, one batch can be used on one side of
edges can be as sharp as razor blades, especially if the new roof and the other batch used on the other
broken. A slate sliding down a roof can therefore side, as both sides are not visible at the same time
pose a serious hazard for anyone working below from the ground.
without gloves. Otherwise, differing batches can be creative-
Some of the slates will break during the ly combined as shown on page 209. If you have col-
process of removal, but it’s better that they break lected slates from two dramatically contrasting

Opposite page: Spiral roof at the roofing school in Mayen, Germany. More German slate work is illustrated in Chapters 14, 15 and 20.
Photo by author .

The Slate Roof Bible — Chapter 16 — Recycling Slate Roofs 203

 s Chuck Smid, owner of The New England Slate Co., Inc. in Pittsford, Vermont, relaxes in a room he has beautifully decorated with recy-
cled roof slate flooring and chimney cladding.

t A blend of recycled roof slates creates a unique look on a vertical wall surface in a Pennsylvania kitchen. The slates are attached to
cement board with thin-set epoxy mortar, then grouted. The cement board is screwed to the existing wall boards.
Photos by author.

204 The Slate Roof Bible — Chapter 16 — Recycling Slate Roofs

 This huge barn near West Middlesex, PA,
shown above left, became scheduled for dem-
olition, so its roof slates were salvaged.

Architect Chris Leininger, left, pries off the roof

slates, which slide down to a waiting plank.

They are then slid down a chute into the barn,

landing on an old mattress (above).

Finally, the slates are taken to Pennsylvania’s

Slippery Rock University Harmony
Homestead and installed on a new building,
shown at left with some of the student con-
struction workers (all women!).

Photo at left shows the slates on an American

lath roof being salvaged by Umberto Perlino
using the same method as above — roof jacks
and planks along the bottom of the roof collect
the slates as they are pried off and slid down.
The slates are then collected from the plank
and either carried down a ladder, slid down a
chute, or dropped to the ground using a rope
and crate.

Photos by author.

The Slate Roof Bible — Chapter 16 — Recycling Slate Roofs 205

 A tornado flattened this Mercer,
PA, garage (top), but the slate roof
was salvaged by astute owners
Mike and Diane Sharr. When the
new garage was built (center), the
original slates went back on.

This Hooker, PA, roof (bottom),

designed by Guido Lesser, dis-
plays a clever mix of sizes, shapes
and colors, yielding an aesthetical-
ly unique recycled slate roof.

Top photo by Mike Sharr, center photo by the

author, bottom photo by Guido Lesser.

206 The Slate Roof Bible — Chapter 16 — Recycling Slate Roofs

All of these roofs are made of recycled
slate and should last several human gen-
erations, if not a century or more. They
include a writer’s residence (above), a
professor’s home (right), a beach
house/sauna (below left), and a poet’s
retreat (below right).

Photos by author.

The Slate Roof Bible — Chapter 16 — Recycling Slate Roofs 207

roofs, such as from a green roof and from a purple faces. They can be laid directly onto the wet con-
roof, then you may want to consider designing a pat- crete, perhaps with a bonding agent painted to their
tern into the roof to take advantage of the color con- underside, or glued to cured concrete or plywood
trast (see also Chapter 15). with an epoxy (thin-set) tile adhesive, or even with
It’s often a good idea to increase the headlap trowel grade roof cement (allow a few weeks drying
on recycled slates when nailing them to a new roof in time when using roof cement as an adhesive). Roof
order to cover up the weather marks that remain on slates can be walked on when laid flat over an
the old slates. If the roof that the slates were unyielding surface, but should not be walked on
removed from had a two-inch headlap, the new roof when on a roof surface where they’re overlapping
should have a two-and-a-half inch headlap, or even each other and likely to break. It’s imperative that
a three-inch headlap. This will give the finished the floor have no “give” to it when using old roof
recycled-slate roof a cleaner appearance. This extra slate as a floor covering. Slates can also be glued to
lapping sometimes poses a problem, however, as the drywall or plywood walls to make a very interesting
nail holes may then become too low and the nails and beautiful wall surface simulating cut stone in
will penetrate the top of the slates in the underlying appearance. Again, epoxy tile cement is best, and
row, which should be avoided if possible. If that hap- with a cutter, a variety of slates, and an imagination,
pens you should punch new holes in the slate, high- the design possibilities are endless.
er up, before nailing. Finally, roof slates can be epoxied to brick
surfaces, such as old chimneys, to make them appear
OTHER USES FOR RECYCLED ROOF SLATES to be stone. In all cases, when recycling roof slate for
decorative purposes, make sure the slate is not soft
Slates can also be recycled for purposes and flaking (use only good, hard slate), and thor-
other than roofing. Painting and decoupage on old oughly clean each slate with soap and water before
roof slate is popular among craftspeople, for exam- use. And remember, if you cut the slate with a hand-
ple. Slates can also be cut up and stacked to make operated slate cutter, the edges will be beveled. If
sculptures, or assembled into such things as doll you want square edges, you’ll have to cut the slate
houses, candle stick holders, or vases, with the prop- with a masonry blade or a diamond blade on a circu-
er adhesives. Roof slates can be engraved with stone lar saw or a grinding tool.
engraving chisels, or lettering and designs can be t Several companies in the United States specialize in the recycling
sandblasted into them using a sandblast stencil. of roofing slates and tiles including Durable Slate Company, Inc. of
Columbus, Ohio, whose stockyard is shown below with co-owner
Old roof slates that are good and solid make Gary Howes. Lists of both new slate and salvaged slate suppliers can
a good floor covering too, especially on concrete sur- be found at jenkinsslate.com and at the back of this book.
Photo by author.

208 The Slate Roof Bible — Chapter 16 — Recycling Slate Roofs

s Two garages roofed with recycled slates in Plain Grove, PA, blend Vermont purple slates with Vermont sea green slates to create a
unique artistic look.

t The residence of Architect N. Lee Ligo AIA and wife Linda MacWilliams Ligo, Tall Chimneys, was built in l994. Among numerous archi-
tectural antiques incorporated into the residence were the sixty squares of recycled 19th century slate originally installed on Pennsylvania
barns. Because of the random colors, shapes and sizes salvaged from multiple demolition sites by Amish crews, the architects Brett Ligo
AIA and Lee Ligo AIA made multiple daily trips to make some sense of organization to the visual integrity of the roof. The slate was installed
over 1x4 hemlock sheathing spaced 4 inches apart. The Amish crews traversed the roof during construction by inserting the toes of their
boots into the four-inch slots between the slats. In most cases the copper nails were driven through the original punched holes in the recy-
cled slate.
Top photo by author, bottom photo by Ligo Architects.

The Slate Roof Bible — Chapter 16 — Recycling Slate Roofs 209

 The Slate Roof Bible • 2nd edition • Part III
Repairing and Restoring Slate Roofs
 Chapter Seventeen

REPAIRS AND RESTORATION

Now I lay me down to sleep; I pray the Lord my roof will keep.
If I should die before it breaks; I thank the Lord I made it slate.
Pam Sykola - slate roof owner, Pennsylvania

T
he things people do to slate roofs to DRIP EDGE
ruin them could fill another book.
Much of this abuse is, ironically, at The drip edge of a slate roof often needs
the hands of professional roofers, which is one rea- repaired because contractors looking for a quick and
son the author came up with the clever theory that cheap way to fasten gutters to a house simply nail
Neanderthals never became extinct — they simply them through the slate using strap hangers. This
evolved into roofing contractors. The greatest threat damages the slates, which eventually have to be
to American slate roofs today is the roofing profes- repaired or replaced.
sion, both due to the improper installations of new It’s important not to allow strap hangers to
roofs and to improper maintenance and repair of old be used on slate roofs unless the hangers are fastened
ones. The vast majority of roofers today in the underneath the slate. Originally, many slate roofs did
United States make their living by re-roofing build- use strap hangers nailed to the sheathing under the
ings. They have a vested interest in destroying older slate because the fascia boards on the older houses
slate roofs because once the slate roof is gone, the were not plumb (straight up and down), making it
brand new “premium” asphalt replacement shingles difficult if not impossible to fasten the gutters to the
will be installed, then replaced regularly and end- fascia. When the old gutters wore out and the old
lessly. Smart people replace their old slate roofs with strap hangers rusted away, the contractors’ solution
new slate roofs, but they have to be careful that the was to nail new strap hangers on top of the roof right
roofers installing their slate know what they’re through the slate, thereby damaging the roof.
doing. But let’s not be repetitive here — slate instal- The proper solution, however, is to rebuild
lation has already been covered in Chapter 13. the fascia so that it is made plumb, and then to hang
There are a variety of routine repair and the gutters on the fascia using fascia hangers. An
maintenance jobs that, if done properly, will keep a alternative is to remove the slate where the hangers
slate roof in good condition for generations. Our are to be installed, nail the gutter hangers to the
focus will be on repairs and maintenance above the wood sheathing, then replace the slate over the
drip edge, which is the very bottom edge of the slate hangers.
where the water drips off during a rain. We will not Often when repairing the slates along the
include anything below the drip edge (such as rain drip edge of a roof, the gutter hangers must be
spouting) in any detail, although rain spouting must removed one at a time in order to replace the broken
be briefly discussed here because many American slates underneath them. When the broken slate is
spouting contractors nail rain gutters on top of slate off, the hanger can be nailed back directly onto the
roofs, which is a mistake that damages them. wood sheathing underneath the slate and the
Flashing and chimneys will be covered more exten- replacement slate can then be installed over the gut-
sively in Chapters 18 and 19. ter hanger. The slate along the drip edge can be
In order to best understand how to do rou- repaired this way without the need to take down the
tine repair jobs on slate roofs, one should first entire rain gutter.
become familiar with the parts of the roof, which are A larger problem resulting from the unfortu-
the drip edge, the sheathing or roof deck underneath nate practice of nailing strap hangers through slate
the slate, the slate itself, the valleys, ridges, flashings is the damage to the wood sheathing underneath the
and chimneys. Let’s start with the drip edge. slate caused by the leaking roof. Because more water
runs over the drip edge than any other part of the
roof, this is the worst place for a leak to occur, and
the wood underneath will eventually rot. In some

The Slate Roof Bible — Chapter 17 — Repairs and Restoration 211

cases, not only do the slates have to be removed and metal as they are much more durable, don’t rust, and
replaced along the drip edge, but so do the boards. don't need to be painted, although one must be care-
In severe cases even the rafter ends will be rotted ful to use the heavier gauge (.032”) aluminum and
and must be rebuilt. This is why roof owners must not the thinner stock, which is not worth putting up.
be especially vigilant in preventing unscrupulous An alternative to aluminum or copper spouting is
contractors from ruining the drip edge of their slate stainless steel, which is harder to get and expensive,
roof by nailing strap hangers through their slate. but exceptionally strong and durable. In England,
The spouting people who do this common but shod- heavy cast iron spouting is popular.
dy work never have to repair the roofs later — that’s OK, so your drip edge is bad and you have to
left to the slaters, and the roof owners must pay repair it. It’s not hard if you know how a drip edge is
twice — once to have their roof damaged and then put together. The bottom course of slate is called the
again to have it repaired! starter course, and it is usually laid sideways. It is an
Much of the older American spouting was invisible row of slate as it lies under the first course.
the galvanized “half-round” type, hung on cast iron Under the starter course is a shim or cant strip, which
strap hangers fastened directly to the roof boards is usually a narrow strip of wood approximately 3/8”
before the slate was laid. Today, however, aluminum to 5/8” thick, nailed or screwed to the sheathing and
or copper spouting are preferable to galvanized running horizontally along the bottom edge of the

Traditional slate roofs are simple

wood and stone roofing systems
that shed water and will do so for
generations. In severe ice-dam-
prone areas, increase the head-
lap at the eaves to at least 4
inches on the bottom 3 feet of
the roof.

212 The Slate Roof Bible — Chapter 17 — Repairs and Restoration

 BUILT-IN (“YANKEE”) GUTTER
These gutters tend to deteriorate if not properly maintained and
must eventually be removed from the roof. Gutter, liner, old wood-
en cant strip, and old starter slate are completely removed. New
cant strip is installed at bottom of sheathing, new starter slate is
installed over cant, and new 1st (and maybe 2nd) row of slates are
installed. Note that a 3” headlap is maintained for all slates. Upper
row is attached using nails and bibs or stainless steel or copper
slate hooks.

wood sheathing traditionally used on slate roofs is

one-inch-thick, rough sawn (unplaned), solid lum-
ber usually from a local source, and usually installed
“green” (not kiln dried). Local, green lumber can’t
be bought at standard lumber yards, but is available
at sawmills, which are abundant in any forested area
such as in most of the northeast U.S. Plywoods, lam-
inated woods, and particle boards are not recom-
mended for slate roofs as these materials can, and
Rain gutters should be attached to the fascia board using do, de-laminate over time. Local lumber is easy to
a fascia hanger. If the fascia is not plumb, it must be
replaced or modified to allow for fascia hangers.
get, costs less, and does not need to be dried before
Alternatively, gutter straps can be nailed or screwed direct- using. Alternatively, 3/4” planed, kiln dried plank-
ly to the roof deck underneath the slate. ing will work fine. This issue is discussed in greater
detail in Chapter 13.
roof. The purpose of the shim is to cock the starter It should be added that many older slate
slate at an angle so it matches the angle of all the rest roofs have or had built-in gutter systems on the
of the slate on the roof. A good shim would be made roofs. Many of the old built-in gutters have been
of cedar or other rot-resistant wood, although almost removed because they weren’t properly maintained
any solid wood strip will work, and it’s convenient to (the metal wasn’t kept painted), and they rusted and
make the shim out of the same wood as the roof leaked. You will sometimes see old slate roofs with a
decking itself (not plywood, though). couple of layers of asphalt shingles along the bottom
After the starter course, the remaining slates edge because the people who removed the built-in
are nailed in the standard way allowing for a stan- gutters covered the exposed sheathing with asphalt
dard 3” headlap, increased to 4” on lower sloped shingles instead of slate as they were supposed to.
(4:12 or 4” of rise in 12” of run) roofs. The headlap is These roofs can be restored by removing the shingles
the amount of overlap each slate has in relation to the and reslating the drip edge.
second course of slate above or below it. Every slate is
overlapped by the course above it, but it’s the over- THE BASIC REPAIR
lap on the second course that’s critical (Roof slope
and slate installation are discussed in greater detail The basic repair job on American slate roofs
in Chapter 13). involves the removal and replacement of individual
As with any repairs, repairing drip edges slates, which must be removed because they’re bro-
requires removal and replacement of the bad slates ken or tarred, but also when they’re covering flash-
(which will be cracked, broken, or tarred), and ing or sheathing that must be replaced. In almost
removal and replacement of rotten boards. The any slate roof repair situation, slates must be taken

The Slate Roof Bible — Chapter 17 — Repairs and Restoration 213

off the roof and then put back on. nail is gasketed, sometimes it is simply covered with
At the bottom of the roof are the starter slates. roof cement or caulk, and sometimes it is neither
Above the starter slates are the standard slates, which gasketed nor covered. This is not the right way to
are full size, uncut slates. At the top of the roof along replace a slate (except in unusual situations)
the ridge are cap slates under metal ridges, which because face nails, including gasketed ones, will
can be relatively small. At the gable ends of the roof eventually leak. An exception is made in the case of
are end slates or half slates, which are cut approxi- dilapidated soft-slate roofs when the roof is sched-
mately in half lengthwise. Then there are the valley uled for replacement and the caulked face nails may
slates, or flashing slates, which are cut to any size or temporarily help hold the roof together until it can
shape to fit against or on top of flashing, and finally be reslated. Contractors face-nail slates because it’s
we have ridge and hip slates, which are used as ridges easier and cheaper than hiding the nail in a slot and
and hips (also known as saddle or comb ridges or flashing over it, or using slate hooks, and most
hips) in place of metal ridge. homeowners don’t know whether their contractor is
The basic slate repair involves the standard doing the job properly or not.
slates, which are the full size, uncut slates that make Slates such as cap slates and end slates don’t
up the bulk of the field of the roof. If one of these have slots to nail through, and are therefore the only
slates breaks, it must be removed and replaced. This acceptable slates for face nailing on hard slate roofs,
is simply done by using a slate ripper to pull the two and even they don’t have to be face-nailed, as we will
nails out of the roof which are holding the slate in see. Let’s take a look at the various slates and how to
place, then sliding a new slate in place and nailing it fasten them in place when replacing them.
with one 1 1/2” hot dipped galvanized or copper In order to replace a starter slate, the overlap-
nail, through the slot overlying the slate. Sometimes ping slates usually need not be removed. The starter
two nails must be used to get a solid replacement job slate can be pulled out with the ripper by hooking its
(when replacing a row of slates, every few slates nails and pulling them out, thereby removing the
should be double nailed to prevent the slates from old slate. Then a new starter can be inserted under-
becoming crooked over time). The nail head is then neath the first row of slate and nailed in place
covered with a piece of metal flashing called a bib through an exposed slot (or two) with a nail and bib.
flashing, which is slid under the overlying slates, but Sometimes the overlying slates must be removed in
over the nail head to make the repair leak-proof. order to get a starter slate out. Once the overlying
A common alternative to this method slates are removed, the replacement starter slate can
involves the use of the slate hook to hold the replace- easily be nailed in place, then the overlying slates
ment slate in place. A slate hook is a hook that nails replaced, with their nails hidden in the slots (or with
into the roof decking between the two slates under- slate hooks). Starter slates lay on a shim strip, and
lying the replacement slate (see illustration, previ- that shim may need to be replaced (at least in part)
ous page). The hook is made of copper, galvanized, in order for the starter slate to lie at the proper
or stainless steel, although the stainless steel hooks angle.
are recommended because they’re stronger and Cap slates do not have exposed slots allowing
longer lasting. After the slate hook is nailed in place, for replacement nailing in the standard fashion, so
the replacement slate is slid into place and the bot- they must be nailed under the ridge metal by prying
tom of the slate is nestled into the hook. The advan- the ridge metal loose and lifting it enough to nail
tage of the slate hook is that no holes puncture the under it. The ridge metal has to be pried loose any-
roof when a slate is replaced, thereby yielding a per- way to get the old cap slates out. In some cases the
manent repair that is virtually invisible from the cap slates can be fastened by nailing right through
ground. They are also very handy when repairing the ridge metal with an 8 penny nail, then caulking
asbestos roofs, side-lapped slates, and other unusual the nail head with lifetime silicon caulk. The disad-
roofing situations. The disadvantage of slate hooks vantage to this technique is that when the ridge iron
is their limited applicability — they can’t be used on is removed for replacement, those cap slates will fall
valley slates, drip-edge slates, and other areas where out.
there is no where to nail them. When a ridge or hip is made of slate, the
It’s common for some roofers to just “face- slate must be removed in order to replace underly-
nail” replacement slates, which means they drive a ing slate .
nail or two through the face of the slate and leave End slates are only half as wide as the stan-
them there, exposed to the weather. Sometimes the dard slates and don’t have a slot over them to nail
214 The Slate Roof Bible — Chapter 17 — Repairs and Restoration
The Slate Roof Bible — Chapter 17 — Repairs and Restoration 215
through. Here is where a face-nail is often used, trowel the mesh in, then coat it with another layer of
although the best method of replacing an end slate is roof cement, being careful to make sure no cement
to simply remove the overlying slate, nail the new overlaps the slate. Repeat, the cement should be
end slate in properly with two nails, then reattach worked under the slate with a trowel, never over it.
the overlying slate with a slate hook or nail and bib. There are many roofs with leaking valleys
End slates (half slates) often benefit from a dab of where a homeowner or roofing contractor has tarred
caulk or roof cement underneath them when being both the valley and the slate on both sides of the val-
replaced (this is not needed or recommended during ley. This defaces the slate and ruins the appearance
routine installations). of the roof, while adding nothing to the effectiveness
Gable-end slates have the unfortunate repu- of the valley repair. If anything, it will make the val-
tation of easily blowing off some roofs (such as old, ley leak worse over the long run, because the water
wind-exposed barns). When gable-end slates are will run down the roof and seep under the roof
being replaced on a roof that suffers from chronic cement, which will act like a dam drawing the water
wind damage, the slates should be bedded in roof into the roof. It is imperative to work the cement
cement. This is done by applying roof cement under under the slate, then when the valley is eventually
the slate before the slate is nailed in place, so the removed and replaced, the slate will still be good,
slates are glued together like a series of peanut but- and the valley replacement job will be much easier.
ter sandwiches, and no roof cement is visible. This This three-step cement and fiberglass repair
little trick will keep those gable-end slates from method is an inexpensive temporary measure to be
blowing off again. used when the roof is not expected to last much
Most flashing slates, such as slates along a longer, or in situations where the roof owner doesn’t
valley, have a slot overlapping them, allowing a place have the money to pay for a permanent roof repair,
for a standard replacement nail and bib. Otherwise, or in an emergency situation. A roof cement and
the overlying slates must be removed, the flashing fiberglass repair may last 10 years, and can also be
slate replaced, then the overlying slates replaced in used to repair almost any leaking surface (flat roofs,
the standard fashion. When very small slates are metal roofs, chimney flashings, and built in gutters,
replaced, it’s often a good idea to bed them in a lit- for example) except slate surfaces. Eventually, the
tle roof cement or silicon before nailing. Punch a roof cement and fiberglass repair will wear thin, but
hole in the small slate with a slate cutter pin or other it can easily be redone and will last quite some time
sharp object, put a dab of roof cement or caulk under this way.
the slate where the hole is, position the slate on the
roof, then nail in place. The cement helps hold the REPAIRING HOLES AND “HIDDEN LEAKS”
small piece of slate in its proper position.
DON’T USE TAR
TEMPORARILY SEALING LEAKING VALLEYS
When valleys leak, the solution is simple —
Valleys are a common source of leaks. Valleys replace them as described in Chapter 20. If you can’t
carry more water than any other part of the roof afford to replace them, seal them temporarily. Yet
because they act as a channel collecting water from there are often leaks on slate roofs that aren’t in the
two roof planes. When the valley wears out, holes obvious places like valleys, chimneys, flashings, and
develop which can leak a large amount of water into missing slates, and these are hard to pinpoint. This
a building, and a pinhole in a valley can leak buck- is where a bit of experience comes in handy. Being
ets of water. The solution to leaking valleys is simply able to find the source of leaks (and repair them, of
to remove the old valley metal and replace it with course) is the true mark of a professional, because
new metal. This is a routine job, discussed in many leaks are caused by something small and can
Chapter 20, and is a sure and permanent cure for be repaired rather easily.
any leaky valley, especially if the replacement metal Many old American slate roofs have been
is copper, stainless steel, or heavy gauge aluminum. ruined by having tar spread all over them.
Sometimes the roof is not worth the cost of Apparently, the repair person didn’t know how to
replacing entire valleys because the slate is soft and look for and locate the source of a leak. Instead, he
nearing the end of its life. In this case, simply spread got out the tar bucket and the brush and went wild,
trowel-grade roof cement on the valley metal, roll hoping he’d hit the leak, which was probably the size
out some fiberglass roofing mesh onto the cement, of a pinhole. There is no greater folly than painting
216 The Slate Roof Bible — Chapter 17 — Repairs and Restoration
a slate roof with tar, yet some contractors advertise HOLES IN SLATE
the “service” of coating slate roofs with brush-on
roof tar! The tar doesn’t totally ruin the roof func- One common source of leaks on slate roofs is
tionally, but it does totally ruin the roof aesthetical- a hole in a slate. Holes often result from nails that
ly, and it takes about 50 years to wear off. In the weren’t nailed down far enough when the roof was
meantime, besides having to look at an ugly roof for installed, or which backed out of the roof as the
the rest of your life, if the roof does need repaired sheathing boards dried. The nail heads then worked
(and it will — that’s why it was coated — it leaked!) against the overlying slate eventually to wear a hole
the job of repairing it properly is much more diffi- right through. If you examine an old slate roof close-
cult when the roof is all glued together with tar. If ly, you’ll likely find these holes, and the guilty nail
you run into a contractor offering to tar your slate heads will be happily peeking through them.
roof, smile, speak gently, humor him, and get rid of They’re easy to fix. Simply tap the nail head down
him as quickly as possible. where it’s supposed to be, then slide a piece of metal
(copper or painted aluminum — brown side facing
out) under the hole and over the nail. A good size for
the metal is 4” wide and 7” long, and it should have
a slight bend in it lengthwise so it doesn’t slide back
out. A dab of clear lifetime silicon caulk in the hole
after the bib has been slid into place will forever
hold it there. You can fix a lot of holes on a slate roof
quickly and inexpensively this way. On very old
large roofs, there could be fifty or more holes like
this. Alternatively, the slate with the hole can be
completely removed and replaced.
Holes in slate can be caused by other things
too. One farmer thought it was a good idea to shoot
the pigeons that roosted in the rafters of his barn.
His .22 caliber rifle might not have killed many
pigeons, but it sure made a lot of neat little holes in
Some buildings, particularly barns, are exposed to excessive wind,
and the windward side repeatedly loses pieces of roof slate along his slate roof. No wonder it leaked!
the gable end during gales, leaving a ragged and damaged roof Then there will always be holes in slate roofs
edge. When these slates are replaced, they should be bedded in
trowel grade roof cement, so that the cement is sandwiched
that have no obvious explanation. Maybe someone
between the slates and is not visible. This simple technique tight- fired a gun in the air a mile away and the bullet hit
ens up the windward edge and prevents the slates from rattling someone’s roof, or maybe it was a miniature mete-
loose again.
orite, or maybe a kid threw his dad’s screwdriver at
The Slate Roof Bible — Chapter 17 — Repairs and Restoration 217
 contracted the roofing to a roofing contractor who
also flashed the chimney that protruded through the
roof. After the flashing job, the roof leaked around
the chimney. The owner called the contractor back
and he “fixed” it. It still leaked. He called him back
again, he “fixed” it again, and, of course, it still
leaked. At this point a competent roofer was called
in to have a look at the problem and the leak was
immediately obvious — the chimney wasn’t flashed
properly. No amount of tinkering was going to make
the chimney flashing waterproof if it wasn’t installed
properly to begin with. The only solution was to tear
it out and do it again. In this case, the roofing con-
tractor didn’t know the secret to flashing a chimney
RIDGE OR HIP SLATES
(a hip is a sloping ridge) (folding the corners, which is explained in Chapter
19 of this book). In the end, the contractor agreed to
The illustration at left shows a “saddle
hip.” These slates must be removed
let the homeowner get someone else to reflash the
when replacing the underlying slates. chimney and he promised to pay the bill, neither of
[From Slate Roofs, 1926, p. 19]
which had been done a full year and a half after the
original flashing job.
Bad flashing jobs on chimneys are wide-
spread, but other common causes of hidden leaks on
slate roofs are faulty old repairs. If you’ve been read-
ing this book and paying attention, you know by now
that when you nail a replacement slate in place, you
hide the nail in the overlying slot and cover it with
non-corrosive flashing, or else you use a slate hook.
Unfortunately, many roof repair people don’t do
either. Instead they create leaks:
1) Problem: they face-nail slates. These are
nails driven through the face of the slate and left
exposed to the weather. They’ll eventually leak, if
a bird on the rain gutter, or maybe . . . well, who they don’t leak right away. Sometimes the face-nails
knows why, but there are sometimes holes in slate are gasketed, sometimes they’re cemented over,
roofs that are totally inexplicable. Again, a piece of sometimes they’re caulked. Eventually they’ll all
flashing slid under the slate will solve the problem leak. Face-nailed slates are obvious, however, and
quickly and easily. Do not tar over the hole unless therefore easy to find and remove, although a lot of
you really like looking at ugly things. people don’t realize that they’re the cause of leaks.
The heads of very old face-nails may completely rust
HIDDEN LEAKS away and the nails will then be very hard to find
unless the roof is examined closely. Ironically, some
This is where the fun begins. Hidden leaks old soft-slate roofs are so aged and rapidly falling
are leaks that roofing contractors “fix” and they still apart that face-nails are the only thing holding the
leak. Most American roofing contractors make their roof together. When an old soft-slate roof only has
living tearing off and replacing asphalt shingles and five or ten years left, face-nailing may actually keep
aren’t very well versed in the art of finding hidden it from falling apart so quickly, provided the nail
leaks on slate roofs; after two or three attempts they heads are kept caulked or gasketed.
just give up, leaving the roof owner pulling his or Solution: On hard slate roofs remove the face-
her hair out and fuming. Ironically, most hidden nails and the ruined slate that was face-nailed and
leaks are caused by roofing contractors. That’s proba- replace the slate. Fasten the new slate properly. On
bly why they can’t find them. old, dilapidated soft slate roofs (especially PA ribbon
Numerous examples spring to mind. One slate), caulk the nail heads with lifetime clear silicon
homeowner who was building his own house sub- caulk and don’t try to take the slates out. Chances
218 The Slate Roof Bible — Chapter 17 — Repairs and Restoration
are that if you start taking a slate or two out, the the liquid to creep in one direction or another along
entire roof will start falling apart and you’ll have the surface of the solid, independent of the force of
created a major headache for yourself. gravity. Water will run sideways or even uphill. This
2) Problem: the repair person used corrosive is an extremely important principle to be aware of
flashing as a bib. When nail heads are covered by when trying to understand leaks on roofs and it per-
flashing that will rust, eventually it does rust away tains particularly to leaks around flashing. The rule
and the exposed nail head, even though tucked of thumb is that water has the capacity to run side-
down in the slot, will leak. ways nearly 2”, which is why the bib flashing (the
Solution: Use your ripper to remove the corrod- flashing that covers the nail on a replacement slate)
ed flashing and replace it with copper or painted alu- is 4” wide. If you have a situation on your roof where
minum or other non-corrodible bib material. When water can run sideways and can find a place to leak
using painted aluminum, use a brown color and within that 2” limit, you may have a leak by capil-
leave the brown facing out. lary action. If you do have a leak by capillary action,
3) Problem: the repair person didn’t cover your roof will probably look like there is absolutely
the nail in the slot with any piece of bib flashing. It’s nothing wrong with it, and you will be driven crazy
not uncommon for a roofer to replace a slate, nail it trying to find the source of the leak. The solution is
in the overlying slot like he should, then leave it like to examine the roof closely where it’s leaking and
that without covering the nail with flashing, as if his look for a place where the lateral overlap on the roof
brain was working fine and then just shut down is less than 2”. This may be a slate overlapping a
before the job could be finished. This is one of the piece of flashing, or a slate overlapping another
hardest hidden leaks to find, because the nail is slate. If you find such a situation, slide more flashing
tucked in right at the top of the slot where it’s hard- metal under the guilty area to reinforce it. That should
est to see, especially from above, which is the most easily solve the problem.
common vantage point for a roofing contractor.
Then the repair nail rusts away until it matches the WATER TRAVELS DOWNHILL (USUALLY)
color of the roof, and becomes invisible.
Solution: When examining the leaking area, A house with a T-shaped slate roof had a
always look in the slots for hidden nails. Look closely. If chimney near the center of the roof. A leak devel-
you find one, renail the slate in the slot and install a bib oped in a bedroom ceiling, but the slate roof above
over the nail. the bedroom showed no sign of a leak. A close exam-
4) Problem: the repair person covered the ination in the attic revealed that the water was leak-
repair nail head with roof cement. Some roofers nail ing in around the chimney, running down a hip
the replacement slate in the slot, then put a dab of rafter, detouring down a jack rafter toward the bed-
roof cement over the nail head instead of flashing. room, dripping on the ceiling’s edge, then pooling in
Besides being ugly, the roof cement eventually wears the center of the ceiling because the old ceiling joists
away and the exposed nail then leaks. These leaks were sagging slightly. The water then dripped
can be hard to find because there isn’t much to see, annoyingly into the room. Repair of the chimney
and like the previous example, close examination of flashing, located on the other side of the house,
the slots in the leaking area will flush the culprit stopped the leak. If a leak shows up in your roof, you
out. Solution: renail and flash. must understand that the water can be entering the
As long as we’re on the topic of leaks hidden roof from any point above the leak.
in the slot, it is worth mentioning that sometimes
slates crack widthwise; the crack is up underneath I’VE TRIED EVERYTHING AND
the overlying slate where it can’t be seen, and a leak I STILL CAN’T FIND THE LEAK
develops where the crack crosses the slot. This kind
of leak can only be found by closely examining the Don’t despair. The author boasts that he can
slots, while maybe wiggling the slate a bit. You must find any leak on any slate roof, and every now and
get your face right down close to see such a crack. then he runs into a tough one. The solution is not
convenient but it’s simple: wait until it’s raining and
CAPILLARY ACTION (OR ATTRACTION) get up into the attic of the house, look for the leak,
trace it back to its origin, mark the spot with a piece
When liquids are in contact with solids, an of chalk or a thumbtack and rag, or anything promi-
adhesive force exists between them that may cause nent, then call your roofing contractor. He’ll come in
The Slate Roof Bible — Chapter 17 — Repairs and Restoration 219
 dry weather, climb into your attic, find the source of
the leak, go up on the roof and fix it. This works.
The author was called to a house where the
chimney suffered from chronic leaking around the
flashing. He asked the homeowner if the chimney
was used for anything, and when he replied that it
was not, the suggestion was made that the chimney
be removed to below the roof line — a routine job.
The owner agreed, and the chimney top was taken
down, the hole was closed up with matching rough
sawn lumber, and the area was slated to match the
rest of the roof. When the job was done, you could-
n’t tell by looking at the outside of the roof that there
had ever been a chimney there. The homeowner was
assured that, with the chimney gone, the chronic
leak had been brought to an end.
A few weeks later the homeowner called and
said it was still leaking. He said he could hear the
water dripping in the roof as he lay in bed during a
rain. So the next day the roof was examined closely.
Nothing could be seen that might be leaking, but all
was double checked and reinforced with some bib
flashings just in case. “I don’t see any leaks, and I’ve
NEVER TAR THE SLOTS ON A SLATE ROOF
never had a chimney removal job leak before,” the
as shown above on an historic house in Mercer, PA, with
excellent sea green slate. This is a popular way to ruin a roof author informed the homeowner, “but it should be
aesthetically, and the tar does not repair the roof. If you think OK now.”
there may be a leak in a slot, slide a piece of metal under the A couple weeks later the owner called again,
slates, do not tar over them! In the photo above, someone in madder than a wet hornet. “It’s still leaking! I heard
the past had walked on the slates, evidently cracking one,
and it subsequently leaked in a slot. The repairperson’s inane
it dripping in the roof last night in the rain!” He
“solution” — tar all the slots! wanted the author to drop everything and get over
Photo by Barry Smith.
there right away; after all, he had already paid to fix
his leak and he was insinuating that he had been
ripped off. So the next day the roof was examined
again, but nothing was seen that could be contribut-
ing to a leak. Finally the owner was informed, “You
have a hidden leak. There are no signs of anything
that would be causing a leak. The only way to fix this
thing is to wait for it to rain again, get up inside your
roof, go to where the chimney is (it was still standing
in the attic), and mark the spot on the underside of
the roof sheathing where it’s wet. Then call me. The
spot you’ve marked will indicate where the leak is,
and then we’ll be able to fix it!”
Well, it wasn’t more than a week later that
we had torrential rains. The rain just beat down in
sheets for hours, and you could really hear it pound-
NAIL HOLE IN SLATE ing on the roof. The homeowner would certainly be
calling, or so it seemed. He didn’t call, however, and
This is a common sight on old slate roofs, especially on
soft slate roofs from Pennsylvania’s Lehigh-Northampton more rain came, another week passed, and he still
district. To repair, simply tap the nail down a bit with a bolt, didn’t call.
and slide a piece of copper or aluminum flashing under the Then, a month later the author ran into the
slate and over the nail. guy at the grocery store. The owner looked at him
sheepishly as if he hoped he wouldn’t be seen. The
220 The Slate Roof Bible — Chapter 17 — Repairs and Restoration
inevitable greetings were exchanged, then the owner author to complain that he had a leak in the same
took the author aside and said, “You know that leak place on his ceiling for fifteen years. He said he’d
I had?” “Yes.” “You know those real heavy rains we had a whole slew of roofers try to fix it and no one
had a few weeks ago, when the rain just beat down ever succeeded. Of course, nothing interests the
like hell?” “Yes.” “Well, I did what you said, I went author more than a challenge like this, so he stopped
up into the roof with a flashlight.” “Yes?” “And it by the man’s house and took a look at his roof. Sure
was just raining like hell, the sound of the rain beat- enough, the roof area directly above the leak
ing on the roof was deafening.” “Yeah? Did you find appeared OK. There was nothing that looked like it
the leak?” “Well, you know what, I watched that spot would be causing water to get through the roof. After
on the roof above the chimney for a full hour with my fifteen years of roofers trying to find this one, it was
flashlight, and guess what — it didn’t leak a drop. It decided that this leak be placed directly into the
was just as dry as a bone.” “hidden leak” category, to be found from the inside
At this point, the author remembered the of the house.
two extra trips he had made to the top of this guy’s This was a bit of a problem because a
roof, and unseemly thoughts began to form in his dropped ceiling had to be removed and a wooden
mind, but he remained polite and made a mental ceiling had to be cut through in order to get at the
note to avoid the fellow in the future. The job had underside of the roof. The homeowner was instruct-
been done right in the first place, but the owner ed to call the next time he saw any leaking occur-
heard some dripping during a rainstorm and imme- ring, and soon thereafter, on a rainy day, he did. A
diately concluded that it was dripping where the drive through the rain to his house and a climb up
roof had been repaired. It was probably dripping into the ceiling with a flashlight revealed a trail of
outside, but nothing would convince the man until water that proceeded up the roof about ten feet and
he got up into the roof during a rain and saw for sideways about four feet to the point of origin. After
himself. measuring the distances and writing them down, the
The moral of the story is this: if you have a leak was mapped. Later, during dry weather, the
leak and can’t for the life of you figure out where it’s author climbed on the roof and went to the leaking
coming from, get into your attic, if possible, and spot like finding treasure with a treasure map. The
look at the underside of your roof on a rainy day. water was coming in at a roof hip because the roof
Who knows, you may find that the leak is a figment slates were cut too short against the hip when the
of your imagination! Otherwise, you’ll pinpoint the roof was installed, and the hip slates covering them
location of the leak and, if you’ve marked it well didn’t have enough overlap (remember capillary
enough so it can be found again on a dry day, it can action). All of this was impossible to see until the
be readily repaired. roof was taken apart. The water traveled from the
On another occasion a fellow called the hip down a jack rafter, then ran sideways on a

The Slate Roof Bible — Chapter 17 — Repairs and Restoration 221

222 The Slate Roof Bible — Chapter 17 — Repairs and Restoration
sheathing board, crossed two rafters and finally A roof cement and fiberglass seal doesn’t
dripped through the ceiling far from the point of ori- need to be ugly; it can be neatly done, and the
gin. This ornery little leak confounded many a cement can even be painted with tinner’s red to
roofer and drove the homeowner crazy for fifteen make it look like real flashing from a distance.
years, but was easily repaired once the mystery had When applying the cement, use a three-inch square-
been solved. edged trowel preferably with a flexible blade. Apply
And by the way, taking a garden hose up on the cement over the flashing on the sides of the
the roof and hosing it down while someone watches chimney and on the slate roof a distance of 3” from
on the inside is not the way to find a leak on a slate the chimney. Use at least a 6”-wide roll of roofing
roof. Such a stunt creates an artificial flow of water fiberglass, placing the fiberglass so it lies on the roof
that does not accurately approximate rainfall. It also 3” and runs up the side of the chimney another 3”
creates unnecessary hazards and impositions on (minimum). It’s critical that the fiberglass be folded
both the roofer and the property owner. A good at a 90 degree angle to lie on the roof and on the side
slater experienced in slate roof repair and restora- of the chimney at the same time in a single piece,
tion will never have to do such a thing. because the area most likely to leak is the crack
where the chimney and roof join. Roof cement will
CHIMNEYS dry and crack over the years and water will leak
right through it if you don’t reinforce the joints with
Chimneys are a common source of leaks on a the fiberglass. You want to run both the cement and
slate roof. They leak around the flashing, which is the fiberglass up the side of the chimney far enough
the metal that seals the gap between the roof and the to cover the existing flashing, so you may have to
chimney itself. The flashing eventually rusts, devel- slightly overlap the fiberglass on the chimney sides
ops holes, then leaks. The solution is to replace the by applying a second layer. If the flashing on the
flashing, which is a routine job on old slate roofs, a side of the chimney is loose, remove it before sealing
job that should be done once every 75 years or so. A the chimney.
good material to use when replacing chimney flash- Use the roof cement liberally, but don’t
ing is 16 ounce copper. We will not go into the spread it anywhere it isn’t necessary. It’s hard to
reflashing of chimneys in any depth here because we remove from bricks, and excess roof cement will
focus on chimneys in Chapter 19. look ugly when the chimney is finally reflashed. Be
However, there are people who don’t want to, aware that when you put roof cement on top of slate,
or can’t afford to pay to have their chimney those slates are aesthetically ruined and should be
reflashed, or they want to stop it from leaking in an replaced when the chimney is finally reflashed.
emergency. Although reflashing is the only perma-
nent cure, the chimney can be sealed at the flashing LEAKS AT RIDGES
with roof cement and fiberglass membrane as a tem-
porary measure. Such a seal could last about ten The ridge is the horizontal peak of the roof,
years, then will have to be redone, or the chimney also sometimes called the “comb” by old-timers.
will have to be reflashed at that time. There are several types of ridges commonly used on
Sealing a chimney at the flashing is done in American slate roofs, but these can be lumped into
the same manner as sealing a valley. The three step two basic categories: metal and slate.
process of applying trowel-grade, plastic roof Metal ridges are far more common than slate
cement over the flashing, working in a layer of fiber- or ceramic tile ridges in the U.S., and are typically
glass mesh, then applying another layer of roof made of galvanized steel, although both copper and
cement, will create a waterproof seal that will last for aluminum ridges are also available. Galvanized
quite some time. The problem with this process, ridge metal, also known as “ridge iron” by slaters,
however, is that it makes the reflashing job consider- and “ridge roll” by manufacturers, will rust and
ably more difficult when that job is finally done deteriorate if not kept painted. The quality of ridge
because all that roof cement must be removed. On iron has progressively dropped over the years, and
the other hand, such a seal is quick and cheap, so a it’s hard to find anything worth putting on a slate
lot of people do it anyway, and if you’re going to do roof. Galvanized ridge iron should be 26 gauge,
it, you might as well do it right. The fiberglass mem- although 28 gauge is more common; 30 gauge should
brane is the essential ingredient any time a leak is be avoided. Galvanized ridge iron must be painted
being repaired with roof cement. approximately every five years with tinner’s red or
The Slate Roof Bible — Chapter 17 — Repairs and Restoration 223
tinner’s green oxide, the traditional American roof- ridge and pry the nails out one at a time by prying
ing paints. against the metal ridge, not against the slate.
When ridge iron is neglected, it rusts and Often, when nailing new ridge iron on old
will eventually leak. When that happens, the solu- buildings, it may seem like the nails aren’t hitting
tion is to replace the ridge iron with new, 26 gauge, any wood, and they may not be. When this happens,
galvanized, or 16 to 20 ounce copper ridge (always simply nail closer to the top of the ridge, instead of
watch out for wasps, bees and bats under ridge near the bottom edge. It’s important that the nails
metal). Traditionally, the ridge metal is nailed in all hit something solid, as ridge iron, being metal, is
place with 8 penny common, galvanized or copper subject to expansion and contraction and the nails
nails (always use compatible metals), and the nail will work loose if not nailed tightly.
heads are cemented with roof cement, caulked with It’s also very common to find old nail holes
lifetime silicon, or gasketed. Rubber or neoprene in the slate along the ridges, and it’s critical when
gaskets can be used on the nail heads when replacing ridge iron to examine the roof closely for
installing ridge, but these tend to leak in time. any exposed nail holes or heads and to caulk them
The ridge iron is nailed in every slot between when caulking the new nail heads on the new ridge.
the slates underneath it. Don’t use screws on ridge One small nail hole near a ridge will cause water to
metal because old rusty, painted screws are extreme- drip through a bedroom ceiling. One dab of silicon
ly difficult to remove without damaging slates when will put a stop to it.
it’s time to replace the ridge metal. Copper ridge It’s a good practice to crimp any exposed ends
metal is preferable to galvanized metal because it of the ridge metal (at each gable end of a gable roof,
doesn’t need to be painted, it lasts longer, and it and at the bottom of each hip on a hip roof) before
looks better. Use copper nails when nailing copper installing it. The end is crimped to keep out bats and
ridge; both copper nails and copper ridge metal are bees, and to improve the appearance of the job.
available through some of the suppliers listed at the Aluminum ridge metal is not recommended
back of this book (or jenkinsslate.com). for use on slate roofs. Aluminum is a bit flimsy and
It’s often a good idea to paint galvanized tends to come loose (usually because it’s nailed with
ridge iron before it’s installed, although new galva- iron nails which react galvanically and rust). True, it
nized metal will not take paint unless it’s first doesn’t need to be painted, and it can be nailed with
primed with a special galvanized metal primer. When aluminum nails thereby avoiding a galvanic reac-
painting new ridge iron, put a coat of galvanized tion, but aluminum ridge just doesn’t hold up like a
metal primer on first, then a coat of paint. Neither heavy gauge galvanized or copper ridge. The ridge is
copper nor aluminum need to be painted. one of the main “walkways” on a slate roof. Roofers
Always remove the old ridge iron before will walk along the ridge to get from one place to
installing new ridge iron. It’s a bad practice to another, and light gauge metals like aluminum will
install new ridge over old, as the old ridge prevents buckle under the weight of a person. This is why
the new ridge from laying well on the roof. A com- ventilated ridges aren’t recommended on slate roofs
mon flat pry bar (“wonderbar”) and slate hammer either. The ventilation should be out the gable ends
work well to remove old ridge iron. Straddle the of the roof, or out roof vents, but not out the ridges

224 The Slate Roof Bible — Chapter 17 — Repairs and Restoration

if it can be avoided. When a person works on slate to remove or punch through a piece of slate if the
roofs day in and day out, he’ll cringe when he sees a slate ever has to be removed.
slate roof with aluminum ventilated ridge, because Old mitered slate hips that spread open over
he knows how difficult it will be to get around on the the years and leak can be repaired by covering with
roof without damaging the ridge if the roof needs ridge iron or copper.
work. Although ventilated ridge will perform well
on a slate roof, it can interfere with the routine RESTORATION
upkeep and maintenance of the roof by obstructing
hook ladders as well as roofers. Slate roofs are made What is the difference between repair and
to last for centuries, and by design they should allow restoration? Often, restoration amounts to repairs
for routine maintenance and upkeep. People who done in such a manner as to not be visible to a
put unusual ridges on slate roofs usually aren’t layperson, restoring the original appearance of the
thinking about having to work on the roof over the roof. In addition, restoration can involve the
next century. removal of an entire original slate roof due to it hav-
Leaks at the ridge are often caused by exposed ing reached the end of its life, and the subsequent
nail heads, both on the ridge iron and on the roof replacement with new slates to restore the roof to its
itself adjacent to the ridge. A little roof cement, sili- original condition.
con caulk, or a well placed bib flashing will quickly Slate roofs are restorable when the slates are
put an end to these leaks. Additionally, the slates still good, no matter how old or how bad the roof
directly under the ridge iron sometimes need to be looks due to abuse or neglect. On the other hand, if
replaced, and in order to do so the ridge must be lift- the slates have worn out, no prayer will save the roof.
ed by prying the nails out. With the ridge lifted up a Following are four examples of restoration
little, the nails can be removed from the cap slates projects. The first (page 227) is a common residen-
using a wonderbar, claw hammer, pointed end of a tial job where the valleys had been so abused by
slate hammer, or ripper, then the cap slates or the “roofing contractors” that the entire roof was almost
slates underneath them can be replaced. given up on. The average home-owner would have
Ridges that are made of slate are simply torn this roof off, but the young lady who owned the
repaired by removing and replacing the slate. Some house knew a good thing when she saw it and decid-
older roofing publications recommend cementing ed to have the roof restored instead. For a fraction of
ridge slates into place as well as nailing them. Don’t the cost of replacing the entire roof, she kept her
do this. In fact, it’s almost never a good idea to rou- good slate roof with the knowledge that it will still
tinely cement or caulk slates into place when last her lifetime.
installing them. Why? Because the guy who has to The Cathedral of St. Andrew in Little Rock,
repair the roof years later will have a big mess on his Arkansas (pages 228-229), provides another good
hands when he discovers that the slates have been example of the proper way to approach an aging
glued together. Use roof cement or caulk under slate roof. In this case, the roof was not repairable
slates only when absolutely necessary — never use it due to the worn out Pennsylvania black slates, 120
routinely. Nothing holds a slate in place better than years old, even though the Vermont green slates were
a couple of good nails, and nails are relatively easy still good. The proper solution was to replace the

The Slate Roof Bible — Chapter 17 — Repairs and Restoration 225

original slate roof with a new slate roof. But that for unknown reasons, it developed some leakage and
costs too much money to be practical in most situa- instead of conducting proper repairs, a contractor
tions, doesn’t it? In fact, the roof, installed in 1880, convinced the owner to pay a huge sum of money to
cost $1,951.50 at that time, including labor and have the entire slate roof removed and then rein-
materials. That works out to a little less than $16 per stalled in the infamous and discredited “economy”
year for a beautiful slate roof that is a work of art, on method — a method that eliminates headlap,
a cathedral no less. Face it, you can’t get any cheap- ignores sidelaps, and instead utilizes felt paper
er than that. When the entire life of the roof is taken between each course of slates to prevent water pene-
into consideration, nothing beats a slate roof for cost tration. Of course, a scant twenty years after this
effectiveness. Of course, the Diocese did the right expensive roofing travesty, the felt paper began to
thing and replaced the old slate roof with a new one, wear thin, rendering the roof a time bomb about to
saving themselves a heck of a lot of money in the spring leaks in every conceivable place. The unfor-
long run. tunate but wise owner decided to restore the roof
The dilapidated barn roof illustrated here on back to its original condition by again removing all
page 231 was also one that, at first glance, looked of the slates and reinstalling them in the proper
hopeless. However, because the slate was still good, the manner, with sufficient headlaps and sidelaps — an
roof was whipped back into shape in just a few days. example of restoration done right, illustrated on
The west gable end had been almost stripped clean page 230.
of slates due to excessive exposure to high winds If you have an historic building and want to
over many years coupled with the inability of the find funding to help pay for its restoration, try con-
owners to maintain the roof. The west end rafters tacting the National Trust for Historic Preservation,
had to be scabbed over with new rafters and all of the 1785 Massachusetts Ave., NW, Washington, DC
sheathing along the west gable end had to be 20036 or browse their publications at www.preserva-
replaced back to the second rafter. Once this was tionbooks.org.
done, matching slates were installed to finish the
job.
The Glenridge Hall in Atlanta, Georgia,
illustrates another type of restoration job. Originally
installed in 1929, it was a beautiful example of slate
roofing craftsmanship done in the “old world” style
with a random slating pattern, eyebrow dormers,
rounded valleys, graduated slate lengths, and a mix
of Vermont slate colors. Fifty years later, however,
226 The Slate Roof Bible — Chapter 17 — Repairs and Restoration
 ROUTINE RESIDENTIAL
RESTORATION

The valley on a residence in western

Pennsylvania at right has been completely
tarred and tarred again, as have the slates on
either side of the valley (a roofing practice some
call the “re-tarred” method). This is a common
sight on older American slate roofs and it looks
so bad that one may think the roof is, at this
point, hopeless. The valley still leaks like a sieve
despite the fact that the “repairs” cost the home
owner a fair amount of money. This is what the
author would call a severe case of Neanderthal
syndrome.

The way to deal with the situation is simple

enough. All of the tarred slates, as well as the
entire tarred valley, are removed. The valley
metal is replaced with new copper, in this case
20 ounce partially hardened “red” (uncoated)
copper. The key to the success of this approach
is simply to have a stock of replacement slates
that will match the existing roof. These slates
must be the same type, in this case Vermont
“sea green” slates, the same size, the same
shape (in this case mostly with scalloped cor-
ners), and about the same age. This is the criti-
cal factor in most restoration projects — you
usually cannot use new slates to restore exist-
ing old roofs. There are some exceptions to this,
but not many. This is perhaps the main reason
more contractors do not do restoration work on
slate roofs (either in Europe or in the U.S.). They
would have to maintain a stockpile of many vari-
eties, sizes, and shapes of salvaged slates,
which is a job unto itself. A reputable slate roof
restoration professional will have these replace-
ment slates or know where to get them.

With the proper tools, supplies, know-how, and

replacement slates on hand, a severely abused
roof such as this can be put back into its proper
shape. At right is the valley replacement com-
pleted. The ridge metal still needs to be
replaced on this project as well as some of the
other tarred slates and other abuse scattered
around the roof surface. Once completed, the
roof looks like it never had anything wrong with
it and it will not leak a drop anywhere. This val-
ley replacement was an afternoon’s job for one
man. No underlayment of any kind was used on
this job — it is totally unnecessary

Photos by author.

The Slate Roof Bible — Chapter 17 — Repairs and Restoration 227

 AN EXAMPLE OF SLATE ROOF RESTORATION DONE RIGHT

The ornate black and green slate roof on the Cathedral of St. Andrew in Little Rock,
Arkansas, reached the age of 120 years before it became a concern to the Diocese (left, shown
before re-roofing). A professional roof inspection revealed that the Pennsylvania black slate on the
roof had reached the end of its life, although the VT unfading green slate was still in good condition.
The only way to properly restore this roof was to remove the original slates and reslate it with new
slates following the original pattern. Welsh black slates from Cwt-y-bugail were combined with
Vermont unfading green slates to restore the original look of the roof. Copper flashings were
replaced with terne coated stainless steel in the critical areas, including the built-in gutters, the val-
leys and ridges. Four pound sheet lead was used as flashing against irregular stone surfaces.
Stainless steel nails were used to fasten the new slates to the original southern yellow pine sheath-
ing.
The ingenious fundraising efforts of Monsignor Scott Marczuk (right), which helped to
finance the roof project, included salvaging the re-usable original slates as they came off the roof
during the re-roofing project, silk-screening an image of the cathedral onto each slate, and selling
them as mementos. He also cut salvaged slates into squares to make coasters and sold them in
packs of four, each wrapped in a ribbon. He even had slate clocks and slate crosses made from
the original slates, raising a considerable amount of money.

HOW MANY BAKE SALES DOES IT TAKE TO PAY FOR AN ORNATE CATHEDRAL ROOF?

One of the most common complaints about slate roofs is their cost. They are just too
expensive to consider installing on most buildings, or so many people believe. The cathe-
dral roof shown at left was installed in 1880 for $1,951.50, including labor and materials.
That works out to a little less than $16 per year for a beautiful slate roof that is a work of
art on a cathedral. Still think slate roofs are expensive? When you consider the life of
the roof, there is no less expensive roof worth buying.

Right: the Cathedral spire is scaffolded for reslating by Midland Engineering.

Below right: Lyle Bandurski, foreman on the project. Bottom, middle: Steve
Kurtz, project manager for Midland Engineering, photographs the new roof;
Bottom, left: Ken Sage, also of Midland Engineering, inspects the new
slate on the rear dome of the Cathedral. Opposite page: Bandurski
proudly displays his work where both the old slates and the new ones
can be see side-by-side.
Photos by author (except aerial photo of old roof at immediate left — photographer unknown).

The Slate Roof Bible — Chapter 17 — Repairs and Restoration 229

 A RESTORATION JOB OF MONUMENTAL PROPORTIONS would best describe
the re-slating of Glenridge Hall in Sandy Springs, Georgia, near Atlanta. The orig-
inal, mixed-color, Vermont graduated slate roof had been removed and re-installed
in the 1970s by a roofing contractor who used the discredited “economy” method
of slating, which eliminated all headlap, instead relying on felt paper between each
course of slate to prevent leakage. Twenty-five years later, the roof had to be
entirely removed and reslated with proper headlap, a job successfully undertaken
by The R.W. Stokes Company of Atlanta. At left is Victor Manuel Avila, job fore-
man, and above is roofing technician Sergio Avila.
Bottom photo by Ron Stokes, other photos by author.

230 The Slate Roof Bible — Chapter 17 — Repairs and Restoration

SLATE BARN ROOFS such as this one in Pennsylvania (top) are often considered beyond hope after a century of battering by Mother Nature,
coupled with owner neglect. The Vermont sea green roof slates were still good, however, and a few days of expert restoration work brought
the roof back almost to its original condition (above). Some woodwork was required on the windward gable end (below). Photos by author.

The Slate Roof Bible — Chapter 17 — Repairs and Restoration 231

 Chapter Eighteen

FLASHINGS

F
lashings are pieces of sheet metal that while 40 lb. terne has .092 lbs. per square foot. The
join a slate roof to objects that pro- manufacturer of terne metals, Follansbee Steel, also
trude through the roof, such as dorm- makes a lead-free terne metal called “Terne II” coat-
ers, chimneys, pipes or skylights, in such a manner ed with zinc and tin (“ZT Alloy”).
as to prevent any water from leaking through the Terne metal makes a good flashing that will
joint. Flashings also act as a joint between different last for many years — 90-year-old terne metal val-
roof planes — valleys join two planes that slope into leys on slate roofs are not uncommon, but terne
each other, while top flashings on shed-roof dormers metal must be kept painted or its longevity is sub-
join two parallel planes of different slopes. Some stantially reduced. In fact, unpainted terne will
flashings act as a joint between the roof and a wall begin to show rust in a year or so. Terne metal has an
abutting either the side, top, or bottom of the roof. affinity for paint, however, and Tinner’s Red or
Green Oxide are traditional paints for painting
TERNE terne on roofs and are available at better hardware
and paint stores or from professional roofing supply
The most commonly used flashing on old outlets. Follansbee sells primers and paints special-
American slate roofs is terne metal flashing, often ly formulated for terne. Terne metal is also available
referred to as “tin.” Terne is a copper-bearing steel pre-painted.
coated on both sides with a lead-tin alloy (80% lead, Now for some good news and some bad news.
20% tin). The typical coating weights of 20 lbs. and The bad news is that most older American slate roofs
40 lbs. refer to the total weight of lead-tin alloy on have been neglected, and the original flashings have
both sides of 112 sheets that are 20” X 28”. In fact, deteriorated to the point that they need replacing.
20 lb. terne has .047 lbs. per square foot of coating, The good news is that almost any slate roof with

Opposite page: German house is clad with German slate near Fredeburg, Germany, where Magog slate is mined. Photo by author.

The Slate Roof Bible — Chapter 18 — Flashings 233

good slates can be reflashed, and in most situations an environmentally friendly, durable roofing system,
no special tools or equipment are required, except with no lead content, that never needs painting.
for an additional hand tool or two that is easily
obtainable (see jenkinsslate.com). LEAD
When removing terne metal flashing from
slate roofs, it’s advisable to replace it with a metal Sheet lead is a very popular flashing materi-
that doesn’t need painted, such as copper, stainless al in Europe and is used there for valleys, ridges, and
steel, lead coated copper, terne coated stainless, or just about everything else on slate and tile roofs.
aluminum. Terne can be used to replace terne, of Again, the prolonged handling of lead can pose a
course, but its use may best be limited to situations health risk to the people using it. Lead poisoning,
where maintenance painting will be done regularly. caused by the absorption of lead into the body, can
Experience has shown that many more roofs go neg- result in anemia and paralysis, so gloves should be
lected than are well maintained, which is the pri- worn when handling lead or lead-bearing metals.
mary incentive for the use of non-corrodible metal. Sheet lead, like copper, is specified accord-
ing to the weight per square foot and is available in
STAINLESS STEEL grades ranging from one to eight pounds per square
foot. Four pounds per square foot of sheet lead
Stainless steel is an extremely durable roof yields a sheet that is 1/16 inch thick. Three or four
flashing and can hardly be surpassed for longevity. pound sheet lead is suitable for such things as lead
Uncoated, it remains shiny indefinitely, which may pipe flashings, for example. Heavier lead sheet may
make it aesthetically unsuitable for some applica- be used for lead roofing.
tions. Stainless falls into several categories: the 300 One positive characteristic of lead flashing is
series typical of flashings are alloys of steel incorpo- its workability — it bends easily and can be made to
rating chromium, nickel and manganese; Type 302 conform to irregular surfaces. It’s also very durable
consists of 18% chromium and 8% nickel and is and highly resistant to atmospheric corrosion, and
most often specified for flashing. It is used inter- will not stain a roof like rusting terne metal or gal-
changeably with Type 304, a lower carbon variation vanized steel will. A drawback to lead is its high
of 302; Type 316 also contains molybdenum; Type expansion rate; allowances must be made for expan-
318 contains 2-3% molybdenum and is more corro- sion and contraction of lead when used in larger
sion resistant than the other types of stainless steel; sheets.
the 400 series is used in interior applications as it
contains no nickel and is therefore less resistant to GALVANIZED STEEL
corrosion. Stainless steel also has the characteristic
of being non-magnetic in most cases. Galvanized metal flashing has been com-
Stainless steel used for detailed flashings is monly used in roofing applications. It is composed
best fully annealed and dead soft. Stainless also of steel or iron coated with zinc on both sides, either
comes in a variety of finishes ranging from non- hot-dipped or electro-plated. It’s fairly inexpensive
reflective to a mirror finish. Terne-coated stainless is and long-lasting if kept painted, although it will rust
type 304 stainless coated with terne and is a popular quickly if neglected and is therefore not recom-
flashing material. The terne coating eliminates the mended for slate roofs. Galvanized metal reacts gal-
shiny surface gloss of pure stainless while making vanically with copper, and these two metals should
the normally difficult stainless easier to solder, not be allowed to contact each other in the presence
requiring no pre-tinning or special preparation for of moisture.
soldering (although pre-tinning is recommended).
Prolonged handling of this material with bare hands ALUMINUM
may pose a health risk because of the lead content.
However, a terne-coated stainless alternative known Aluminum is currently perhaps the most
as TCSII, produced by Follansbee, contains no lead popular flashing material in America for use on
at all. The terne coating is on dead soft Type 304 asphalt roofs. It comes in a natural silver-gray color
stainless steel and consists of zinc and tin (“ZT (mill finish), or coated with paint. The material is
Alloy”). TCSII comes in three gauges ranging from readily available at most building supply centers
28 ga. (.015”), to 26 ga. (.018”) and 24 ga. (.024”). because it’s used for soffit, fascia and siding, as well
When soldered with pure tin solder, TCSII creates as flashing, and can be bought in 50-foot rolls (“coil-
234 The Slate Roof Bible — Chapter 18 — Flashings
stock”). It is light in weight, the thinner gauges are MECHANICAL PROPERTIES OF COPPER
easily bendable, and it is highly resistant to corro-
sion due to the protective oxide that forms on the TEMPER TENSILE STRENGTH (KSI) YIELD STR.
surface of the metal. Much of the mill finish alu- MIN. MAX. (KSI)
minum available in rolls is too thin (.015”) for any 060 soft . . . . . . . . . . . . . . . . .30 . . . . . .38 . . . . . .?
use on a slate roof, and even the painted aluminum H00 cold rolled 1/8 hard . . . .32 . . . . . .40 . . . . . .20
H01 cold rolled 1/4 hard . . . .34 . . . . . .42 . . . . . .28
(.019”/.020”) should be avoided for any long term H02 half hard . . . . . . . . . . . . .37 . . . . . .46 . . . . . .30
flashing jobs when copper or stainless steel are avail- H03 3/4 hard . . . . . . . . . . . . .41 . . . . . .50 . . . . . .32
able. Painted aluminum does, however, make excel- H04 hard . . . . . . . . . . . . . . . .43 . . . . . .52 . . . . . .35
Source: Copper Development Association, Palatine, IL (1 ksi=1000 pounds/square inch)
lent bib flashings for covering the nails of replace-
ment slates (see Chapter 17). Heavier gauge alu-
minum (.032” - .040”) will make a suitable valley on not be placed in contact with these metals in the
a slate roof, although care must be taken to use alu- presence of moisture.
minum nails whenever nailing aluminum valleys Copper flashing may be sold as either
into place. “sheet” or “strip” — sheet copper according to the
Copper Development Association in England (1951)
COPPER being of exact length, over .0006 inches thick, but
not over 3/8” thick, and over 18” wide; while strip
Copper is a non-magnetic, malleable, corro- copper falls into the same thickness range but may
sion resistant metal which shines like brass when be of any width and usually comes in coils.
new, but soon turns reddish brown upon exposure to According to the American Copper
the elements, and finally green. The most common Development Association (www.copper.org), archi-
flashing material recommended today for use on tectural copper usually falls under ASTM B370, con-
slate roofs is 16 ounce copper, which gets its name sisting of 99.9% copper available in six tempers as
from the fact that it weighs 16 ounces per square follows: 1) 060 (soft); 2) H00 (cold rolled, 1/8 hard);
foot. An even more durable copper flashing is 20 3) H01 (cold rolled, high yield); 4) H02 (half hard);
ounce, which, of course, weighs 20 ounces per square 5) H03 (three quarter hard); and 6) H04 (hard). The
foot, although the 16 ounce may be more workable harder the copper, the stronger it is. Dead soft cop-
with hand tools when detailed work is required. per (060) is not recommended for most building
Copper has long been the slate roof flashing projects; instead, cold rolled (H01) is preferred. Half
of choice in America because it’s durable without hard copper is superior in valleys and other applica-
needing painted; it develops a green patina with age tions where extra strength and durability is
that many people find aesthetically pleasing, and required. Copper can be softened by annealing, or
which is said to form a protection against corrosion; heating to a dull red with a propane torch and either
and most importantly perhaps, it’s easy to work quenching in water or allowing to cool naturally in
with. Sixteen ounce copper is easy to bend, and can the atmosphere.
be bent by hand in most cases, or with a pair of sheet Lead-coated copper is copper coated on both
metal hand tongs. Additionally, pure copper doesn’t sides with lead and is popular among architects
present the toxic hazards that lead-bearing metals because it remains dull gray in color, is durable, and
such as sheet lead, lead-coated copper, terne, and is easy to solder.
terne-coated stainless do, exposure to which can
have an adverse effect upon the health of the people GALVANIC CORROSION
who handle it regularly for prolonged periods. The
mining of copper certainly does its share of environ- “Galvanic action,” simply stated, is the cor-
mental degradation, yet roof flashing must rank as rosive reaction between incompatible metals. The
one of the more honorable uses of the metal, and corrosion is expedited by an “electrolyte,” which is a
surely its costs are justified. non-metal substance which will conduct an electric
Copper, like all metals, does benefit from current — water, for example, makes a good elec-
paint, which will prolong its life indefinitely. It must trolyte, and salt water is even better. Metals that are
also be nailed with copper, brass, or stainless steel more electro-positive (anodic) corrode more easily,
nails, as galvanized nails will corrode in contact with and metals that are more electro-negative (cathodic)
copper flashing. Copper reacts galvanically with alu- are more corrosion resistant.
minum, steel, zinc, and galvanized steel, and should The farther apart metals are on the galvanic

The Slate Roof Bible — Chapter 18 — Flashings 235

 PROPERTIES OF METALS GALVANIC ACTION CHART
Source: Architectural Sheet Metal Manual, p. 9.8-9.12.
To minimize the possibility of corrosion, avoid contact
METAL COEFFICIENT OF EXPANSION TENSILE STRENGTH
between metals at opposite ends of the chart.
Lead - - - - - - - - - - - - - - - -0.0000164 in./in./0F. - -? Terne metal should avoid aluminum and copper.
Aluminum - - - - - - - - - - - - -0.0000129 - - - - - - - - -22,000 p.s.i.
Terne Coated Stainless - - -0.0000096 - - - - - - - - -80,000 p.s.i.
Stainless Steel - - - - - - - - -0.0000096 - - - - - - - - -over 80,000 p.s.i.
Copper - - - - - - - - - - - - - - -0.0000094 - - - - - - - - -36,000 p.s.i. + MORE ELECTRO-POSITIVE (Anodic)
Galvanized Steel - - - - - - - -0.0000065 - - - - - - - - -50,000 p.s.i. Zinc
Terne - - - - - - - - - - - - - - - -0.0000065 - - - - - - - - -45,000 p.s.i. Aluminum***
[Lead expands much more than galvanized steel when heated.] Galvanized steel (Avoid copper)
Cadmium
Mild steel, wrought iron
Cast iron
Stainless steel (types 304 and 316 active)
Lead-tin solder
Lead
Brass, Bronze
Copper**
Stainless Steel (types 304 and 316 passive)*
—
MORE ELECTRO-NEGATIVE (Cathodic)

* This stainless steel is chemically treated, usually with an acid solu-

tion, to be made passive. **(Avoid uncoated aluminum, steel, zinc, or
galv. steel). ***Anodized aluminum is considered compatible with all
other metals.

Source: Architectural Sheet Metal Manual - 5th edition; Sheet Metal and Air Conditioning
Contractors National Association; p.9.13.

scale, the more they will react with each other. For less, however, than with either lead or zinc.
example, zinc and aluminum will react with copper Nevertheless, the expansion and contraction of cop-
much more than they will with each other. per creates limitations in its use, and the Copper
Therefore, it’s important to avoid using incompati- Development Association warns, “It cannot be too
ble metals in contact with each other when installing strongly emphasized that the superficial area of each
flashing. If such contact seems unavoidable, place a individual piece of copper sheet or strip must not be
layer of roofing paper, roof cement, paint, or other greater than 14 square feet for thicknesses up to and
non-absorbent, non-conductive material between including .022 inches . . .” When large sheets are used
the metals. in flashing situations, the copper sheets must be fas-
USING COPPER tened to the roof with copper cleats to allow for
movement of the metal.
According to the Copper Development The Architectural Sheet Metal Manual (1993)
Association (CDA) in England, recommends the use of 50/50 solder (50% lead and
50% tin) when soldering copper, and recommends
“The aim of the sheet copper worker must be to that the flux be neutralized (flushed with soda
achieve the necessary shape or form with as little water) after soldering. Many flashing jobs on typical
actual working of the metal as possible. Thus it slate roofs may not require soldering; nevertheless a
will be seen that the working techniques of other section on soldering is included later in this chapter
metals are not always applicable.” for those situations where soldering is
required or preferred. See Chapter 21
Copper expands and contracts for a section on soldered-seam (also
under varying temperature condi- called “lock-seam,” “flat-seam” or
tions; sheet copper expands 1/8” per “flat-lock”) copper roofing.
ten feet of length for a hundred degree
temperature change. The amount of
movement that takes place for a given
temperature variation is about 40%

236 The Slate Roof Bible — Chapter 18 — Flashings

 BASIC FLASHING PROBLEMS Some of the standard commercial skylights come
with pre-formed flashings which may need to be
Older slate roofs develop two primary flash- modified to fit your particular situation. Flashings
ing problems: deteriorated valley flashing (see are easy to make, so it may be advisable to make
Chapter 20) and deteriorated chimney flashing (see your own rather than buying expensive, generically
Chapter 19). A third, less serious, but still common pre-formed skylight flashing. Remember this rule
flashing problem involves deteriorated sewer vent when making step flashings: the bottom of the step
pipe flashings (illustrated in this chapter). Other flashing should line up with the bottom of the slate above
flashings that wear out on slate roofs include dormer it, and the top of the step flashing should line up with the
step flashings (sides of dormers), dormer top flash- top of the slate below it. If the step flashing must be
ings on shed roof dormers, skylight flashing, and fastened (nailed) to the roof, then allow an inch or
flashings that connect the slate roof to other roofs, or two of flashing to extend above the top of the slate
to the outside walls of the building. below it for nailing. If it fastens to the skylight, that
won’t be necessary.
SKYLIGHTS Skylights that lay flush with the roof usually
fall into the “home-made” category, which means
Skylights fall into two general categories as that they’re relatively inexpensive, and if done right,
far as flashing is concerned: those that protrude work well. The outer piece of glass on the skylight is
above the surface of the roof, and those that do not. laid into the roof as if it were a big shingle. It’s
The ones that protrude above the roof should be flashed only on the bottom edge, while the sides and
flashed in a manner similar to a chimney — the top are overlapped by slate. This piece of glass
sides should be step flashed either with one-piece should be tempered safety glass, and should overlap
step flashing or step and counter flashings; the bot- the roof sheathing by three inches minimum on all
tom should have an apron flashing; the top should four sides. It is laid directly on the felted roof
have the largest piece of flashing which extends well sheathing on a generous bed of roof cement, and held
up under the slate (at least 12”); and all four corners in place by the heads of roofing nails tacked in
should be folded (or soldered) to prevent leaking. around it on the corners. Wider pieces of glass may
require a wooden support or two (a horizontal 1x1
for example) to prevent collapse under unusual
snow weight, or when a cat’s up there walking on it.
It’s important to know that a single piece of glass,
when used as a skylight, will condense moisture on
its interior surface, and drip water when used on a
heated building in cold weather. The solution to this
is simply to install another piece of glass interior to
the skylight, and a double paned glass panel is even
SKYLIGHTS better (as far as heat retention is concerned). The
Flush skylights, as above, are single panes of tempered safety glass drawbacks to “home-made” flush skylights are that
worked into the roof like giant slates, then finished on the interior with
another double pane of safety glass to create a triple pane roof win- they don’t open and can’t be used for ventilation,
dow. Standard commercial skylights, as below, are flashed into a slate and may be difficult to clean. However, they will
roof in the same manner as a chimney. Photos by author. greatly increase the amount of natural light entering
a room and therefore reduce the amount of electric-
ity needed for lighting.

SEWER VENT PIPES

Nearly every home and building has at least

one sewer vent pipe protruding through the roof.
The flashing on these pipes wears out eventually and
must be replaced. Most of the old flashings were
made of either copper or lead, lead being the more
common. Today they can be replaced either with
pre-fabricated lead, aluminum/neoprene, rubber, or

The Slate Roof Bible — Chapter 18 — Flashings 237

made-to-order lead or copper flashings. The most another inch or two for nailing purposes if desired.
durable are the lead and copper flashings, although Lay the step flashing about 3”-4” horizontally on the
lead carries with it the hazard of handling a toxic roof and about 2”-4” vertically up whatever it is
metal. The most widely available flashings are either you’re flashing.
aluminum/neoprene or rubber, because these are Some dormers don’t have slate on their sides
typically used on asphalt shingle roofs and can be and there is no way to get the step flashing under-
bought at most building supply centers. Lead and/or neath the siding. In that case you may have to be
copper vent pipe flashings may be available through content with tightly nailing the step flashing to the
your local plumbing contractor, building supply out- side of the dormer against a backing of silicon caulk
let, or roofing contractor. See the illustrated lead or roof cement, leaving the vertical section of the
vent pipe flashing fabrication sequence in this chap- step flashing exposed, or covered by a piece of wood
ter. trim. This is a last resort, however, as both vertical
Vent pipes are found in a variety of diame- and horizontal sections of the step flashing should
ters, the more typical ranging between 1” and 4”; it be covered by slate and siding. Counter flashing can
is therefore necessary to measure the pipe diameter, also be used to cover the vertical sections of step
as well as the roof angle, and often the length of the flashings, and the counter flashing can be bent and
pipe as well, before ordering a pre-fabricated flash- set into a reglet (groove) cut into the side of the ver-
ing. If no suitable flashing is available, try having tical wall.
one made at a local sheet metal shop.
When replacing old vent pipe flashings, the TOP FLASHING ON A SHED ROOF DORMER
same flashing rules apply: remove enough slates
from the roof to completely expose the old flashing, Flat roofed (shed roofed) dormers on slate
remove the old flashing and replace it with new, then roofs can sometimes cause problems because they
re-slate around it making sure that the slates and don’t have the slope that the rest of the roof does,
flashing overlap in the direction of water flow. On and therefore rain and snow don’t drain off of them
steep roofs less expensive store-bought flashing may fast enough. This becomes a real problem when the
have to be forcibly bent to align properly with the flashing that ties the shed roof to the main roof
slope of the roof. becomes deteriorated and begins to leak. However,
this flashing can routinely be replaced, and this is
STEP FLASHINGS the beauty of a slate roof — it can be taken apart, the
flashing replaced, and the roof put back together
Step flashings wear out on dormer sides on again whenever necessary.
old slate roofs after a century or so and must be The procedure for replacing the top flashing
replaced. Often the sides of the dormers as well as on a shed roof dormer is basically the same as for
the roof are covered with slate, so replacing the step replacing any flashing: remove the slates to com-
flashing is simply a matter of removing the slates pletely expose the flashing, pry the old flashing off
from the sides of the dormers (after numbering the roof, replace it with new metal, then replace the
them), then removing enough slates from the roof to slates. When replacing the slates, substitute good
completely expose the pieces of step flashing, one at ones for any that are cracked, broken, or tarred.
a time. The step flashings are then pried off one at a Number the slates with a nail when random
time until all are removed; then they’re replaced one width slates are used (numbering isn’t necessary
at a time with new material as the slates are nailed when uniform slates are used), keep the slates near-
back in place. After all the step flashings are by after removing them so they’ll be handy when
replaced, the slates on the side of the dormer are you replace them, use the same slates whenever pos-
nailed back on — an easy job if they were numbered sible when re-slating, and put them back in the same
ahead of time (e.g., row A1, A2, A3, B1, B2 etc). The spot (when they’re random widths). A top flashing
flashing can be nailed either to the side of the replacement sequence on a random width slate roof
dormer or to the roof when being installed. is illustrated on pages 242-243.
When installing step flashings, remember
the simple rule: line up the bottom of the step flash- SOLDERING
ing with the bottom of the slate on top of it, and the
top of the step flashing with the top of the slate Soldered flashings are not typically required
underneath it. Extend the top of the step flashing up when doing general slate roof restoration. However,
238 The Slate Roof Bible — Chapter 18 — Flashings
on some occasions one may wish to solder something The official definition of soldering is “a
(e.g. a finial, a built in gutter, a cupola, or a shop- group of welding processes which produces coalescence of
fabricated vent pipe flashing) so a brief review of materials by heating them to a suitable temperature and
soldering principles is appropriate. by using a filler metal having a liquidus not exceeding
Simply stated, soldering is the act of joining 450 degrees C. (840 degrees F.) and below the solidus of
two pieces of metal with a molten metal or metal the base materials. The filler metal is distributed between
alloy. For our purposes, soldering involves joining the closely fitted surfaces by capillary attraction
copper to copper, or lead-coated copper to lead coat- [American Welding Society Soldering Manual, 1978,
ed copper, terne to terne, terne coated stainless to p. ix].” The solidus temperature is the highest tem-
TCS, or stainless to stainless, using lead/tin or pure perature at which a metal or solder is completely
tin solder. There are enough problems involved in solid, while the liquidus temperature is the lowest
soldering aluminum that the Architectural Sheet temperature at which a metal or solder is complete-
Metal Manual states that it cannot be soldered. ly liquid.
The Slate Roof Bible — Chapter 18 — Flashings 239
Plumbing vent pipe flashings tend to wear
out and leak on older buildings. Institutions
often have pipes that are unusually high or
large in diameter, and replacement flash-
ings must be custom made. Sheet lead is a
common material for this purpose, although
16 ounce copper is often used as well and
can be used following the same procedures
with some minor variations. Lead is a very
malleable metal and can be easily bent or
formed. It is advisable to wear gloves when
working with lead.

240 The Slate Roof Bible — Chapter 18 — Flashings

The Slate Roof Bible — Chapter 18 — Flashings 241
 t BEFORE - The entire length of the old copper top flashing is pit- t AFTER - New 20 ounce copper top flashing on this dormer will last
ted, leaking, face-nailed and spot-tarred. for generations.

t 1 - Number 3 rows of slates 1A, 1B, 1C..., 2A, 2B, 2C... etc - (num- t 2 - Carefully remove lower slates by pulling out the nails with a
ber random width roofs only), remove top row with slate ripper. flat pry bar (continued on next page).

If your mind is still functioning after read- ing wetting of the surface. Fluxes fall into three gen-
ing that, let’s continue. “Wetting” is when a molten eral categories: corrosive, intermediate, and non-
solder leaves a continuous, permanent film on the corrosive. The mildest flux that works should be the
base metal surface, often referred to as “tinning” or one chosen for the job. Corrosive fluxes remain
“pre-tinning.” Wetting makes the soldering action chemically active after soldering and can cause cor-
possible, and although pure lead doesn’t readily wet rosion to the joint, which is why they’re not used for
(or adhere to) either copper or steel, a tin/lead solder electrical applications (for example).
readily wets both, which is why solder contains tin. Highly active and corrosive fluxes must be
The solder is drawn into the joints by capil- used on stainless steel, high alloy steels, and galva-
lary attraction, and a space between the joints of nized steel because they have hard oxide films,
about .15mm or .005 inches is suitable for most although rosin (non-corrosive) fluxes are satisfacto-
work. A clean surface free of oxidation is critical to ry in most cases for soldering terne metal. Fluxes
ensuring a sound soldered joint, and some fine steel such as Ruby Fluid contain zinc chloride and are
wool will clean most surfaces adequately prior to sol- considered corrosive fluxes. The soldered areas
dering. Solder that is 50% tin and 50% lead is suit- where a corrosive flux was used should be washed
able for use on copper, lead sheet, galvanized steel, after soldering using water with baking soda added.
stainless steel, terne metal, and terne coated stain- Copper tends to form less tenacious oxide
less (although when soldering Terne II or TCSII, a films, and therefore mild (non-corrosive) fluxes are
100% tin solder is recommended if a lead free proj- suitable when soldering it. Non-corrosive fluxes all
ect is desired). have rosin as a common ingredient.
Prior to soldering, a flux is applied to the After the flux is applied, heat must be
surfaces for the purposes of additionally cleaning applied to the metal to be soldered. This is typically
away oxides, preventing re-oxidation, and promot- done by heating a soldering iron and placing the sol-

242 The Slate Roof Bible — Chapter 18 — Flashings

s 3 - Work from one end toward the other when removing the slates. s 4 - Expose and remove the old flashing. Work off planks if the
Starter slates are underneath 1st row and here have no shim. roof is not too steep, otherwise use roof jacks and planks.

s 5 - Remove any bad slates that were under the flashing. s 6 - Replace the bad slates and sweep the roof.

s 7 - Nail in the new flashing (in this case 20 ounce copper bent s 8 - Begin re-slating in the reverse order, putting same slates in
over the edge of a ladder). Underbend flashing so it will fit tightly. original spots. Align with weather marks. Avoid nailing through metal.

s 9 - This flashing is bent 6” on dormer and 10” on main roof, and s 10 - Top row of slates are fastened with nail-in-slot and bib
is nailed along top edge only. flashing technique. Photos by author.

The Slate Roof Bible — Chapter 18 — Flashings 243

dering iron on the metal with the solder in close flushing with a 2% hydrochloric acid solution, then
proximity. The solder will then flow into the with hot water containing some sodium carbonate,
cleaned, fluxed joint as the iron and solder are slow- then with clean water.
ly moved along the joint. It may help to wet (pre-tin) It’s important to remember that all soldering
the metal with solder before soldering, although fluxes give off fumes and smoke when heat is
wetting and soldering can take place in one opera- applied, and these may be toxic. Metals such as cad-
tion. This is a part of the process that has a few vari- mium, lead, zinc and their oxides may also be toxic
ables, such as the amount of heat, type and size of when present in the atmosphere as fumes or dust.
soldering iron, etc, that will vary according to the Therefore, adequate ventilation is imperative when
type of metal being soldered, and these details must soldering any metal. Soldering fluxes containing
be ascertained by the artisan doing the work. For zinc chloride may produce severe burns and der-
example, copper may require a hotter iron than steel matitis if allowed to remain on the skin for any peri-
because it has a greater rate of conductivity, while od of time.
stainless steel may require a cooler soldering iron Two typical solder joints related to flashing
and longer contact. Practice soldering on a piece of are the lap seam and the lock seam (below). The lap
scrap before doing the actual work if you need to fig- seam can be joined with rivets of a compatible metal
ure out these details. before soldering, although the joint as well as the
After soldering, the soldered joint should be rivets must be soldered. The flat lock seam can be
encouraged to cool as rapidly as possible without cleated to an underlying structure before soldering,
cooling so quickly as to warp. Non-corrosive, rosin- if needed (see Chapter 21).
based flux residues do not need to be removed after
soldering. Zinc chloride fluxes can be removed by

Sources of Soldering Tools and Accessories: Jenkinsslate.com; Insto-Impala

Inc.; Flame Engineering, Inc.; North American Bocker; Primus-Sievert Inc.

244 The Slate Roof Bible — Chapter 18 — Flashings

The Slate Roof Bible — Chapter 18 — Flashings 245
 TYPICAL FLASHING SCENARIOS ON AN OLDER,
RESTORABLE SLATE ROOF.

Above are photos of a brick bell tower on a church in Mercer,

Pennsylvania. The photo above left shows a common sight — old
flashing buried in tar, and broken slates where the roofers walked on
and damaged them over the years. The repairs were faulty and it
should be no surprise that a persistent leak occurred there. The only
permanent solution was to remove all of the offending materials
including the old tar, flashings and broken slates, and replace them.
The photo above right shows the job completed in copper, a day’s
work for an experienced slate roofer and a helper. The slate was
Pennsylvania black, 104 years old and still in good condition.

The same church, shown at left, also had deteriorated valley flash-
ings. The old metal has been removed and new 20 ounce half-hard
copper valley flashing has been installed. The slates are now being
nailed back into place. Note the board roof deck and the absence of
underlayment (felt paper). Although felt paper had been installed on
this roof over a century ago, it was now deteriorated to the extent of
being practically non-existent. The new valley was installed with no
underlayment whatsoever and was, of course, leak free. Although felt
paper is recommended when installing a new slate roof, it is the slate
and the flashings that permanently keep the water out of the roof, not
the underlayment. For more on this issue, see Chapter 13. For more
about valley flashings, see Chapter 20.

Photos both pages by author.

246 The Slate Roof Bible — Chapter 18 — Flashings

 NEGLECTED CHIMNEY FLASHINGS ARE NOTORIOUS PROBLEM AREAS ON OLD SLATE ROOFS (ABOVE)

Chimney flashings will deteriorate and leak after many years, and they must be replaced. This is routine maintenance on old slate roofs as the
metal flashings simply do not last as long as the slates, in many cases. The photo above left shows an old chimney with deteriorated flashings
and some tar patches, a candidate for reflashing. The same chimney, above right, has been reflashed with new copper using the “folded cor-
ners” flashing method described in Chapter 19.

BUILT-IN GUTTER REPLACEMENT BENEFITS FROM STAINLESS STEEL (BELOW)

Built in or “box” gutters are notorious for wearing out on older slate roofs. The gutters on the Cathedral of St. Andrew in Little Rock, Arkansas,
were originally copper and had already been replaced once in the 125-year history of the roof. When the cathedral was reslated with new slate
in 2002-2003, terne coated stainless steel gutter flashing, instead of copper, was installed in order to add an extra element of longevity to the
job. The photo below shows the job in progress. The scaffolding platform, collecting slate dust, allows easy access to the lofty job.

The Slate Roof Bible — Chapter 18 — Flashings 247

 Chapter Nineteen

CHIMNEYS

C
himneys on old slate roofs present a 8” standard thickness brick that were solid, with no
variety of maintenance and repair holes in them. Therefore, when rebuilding an old
issues. First, the flashing wears out chimney, the same size and type of bricks are recom-
and must be replaced. Secondly, the mortar becomes mended. They go by the name of 4x8 “pavers,” and
soft, especially above the roof-line, and the top of the are a little more expensive than bricks with holes,
chimney must be rebuilt periodically. Third, many but they offer greater fireproofing protection
old chimneys no longer serve a functional purpose because they’re solid brick.
in the house and are no longer used. These chimneys The chimneys found in most older American
should be removed to below the roof-line and the houses with slate roofs are almost universally devoid
roof closed up. In some cases, chimneys must be of ceramic chimney liners, which are additions to
rebuilt from the attic floor, rather than from the chimneys that became popular in more modern
roof-line. These are all routine maintenance jobs on times, when bricks began to be made with holes in
old slate roofs. them to save on material costs and cut down on their
An old style of chimney construction some- weight. The liners added an additional firewall for
times found in old farm houses involves building the protection. In the old days, chimneys were used to
chimney on a wooden platform elevated off the floor vent smoke and gasses from coal and wood burning
of the house. These chimneys may not even have a stoves, which tend to burn hot and inefficiently.
wooden pedestal underneath them, but instead may Today, most chimneys vent either the more efficient
be supported only by a wooden shelf propping the “air tight” stoves, or gas/oil furnaces, both of which
massive brick structure five feet off the floor! Most burn cooler than the old-time heaters. Cool burning
chimneys, however, are built from the basement woodstoves are notorious producers of creosote,
floor up through the house and on through the roof. which can leak through brick chimneys and even
Older chimneys were typically built of 4” x ceramic liners.
Opposite page: German Chimney Photo by author.

The Slate Roof Bible — Chapter 19 — Chimneys 249

 When rebuilding an old chimney or part of
it, the original style should be imitated, unless the
entire chimney will be rebuilt; then any style can be
used. However, the old style of using solid bricks
laid up without a ceramic liner is a tried and proven
style, and many thousands of these old chimneys are
still in service after a century of use. Nevertheless,
old chimneys can be dangerous, especially if the
mortar and/or bricks become soft enough to crumble
and allow flames to escape to a flammable surface
during a chimney fire. Chimney fires are unlikely
when the chimney vents only a gas or oil furnace,
because these don’t create an accumulation of cre-
osote as a wood stove does. When using an old chim-
ney to vent a wood stove, the chimney should be
inspected closely beforehand to make sure it’s safe.
If it doesn’t appear to be safe, it should be complete-
ly rebuilt or lined (with a stainless steel liner, for
example).
Another peculiar style of chimney construc-
tion that was once common involved the practice of
building a section of the chimney, usually in the
attic, at an angle. Once through the attic floor, the
s New York red slate blocks and shingles create an elegant chimney was angled so the top would exit the roof
Vermont chimney that is a work of art. Photo by author. directly through the center of the ridge — a style
adhered to by certain ethnic builders. It’s these lean-
t Strings anchored to the floor and ceiling make great plumb ing chimneys that must often be rebuilt from the
guides when laying a chimney. attic floor because of deteriorating bricks or mortar,
which can create quite a hazard if the chimney
should begin to collapse. When rebuilding a leaning
chimney, it should be built straight and plumb, after
which it will exit through the roof slightly to one
side of the original hole. New roof sheathing that
matches the existing sheathing is simply added to
fill in the hole after suitable framing material has
been nailed into place. The area is then reslated as
the chimney is flashed. See Chapter 13 for more
information on roof sheathing.
When building a chimney for a new build-
ing, be aware that there are best and worst locations
to build them. The best location for a chimney is
inside the structure and through the peak of the
roof. Inside chimneys stay warmer, radiate more
heat throughout the building, and develop less cre-
osote problems than cooler, outdoor chimneys. The
emergence of the chimney at the peak of the roof
prevents any water from pooling up against the
chimney. From a roofing point of view, a chimney
built up against the outside of the building through
the peak of the roof works just as well as one built
inside the building. However, from a heating point
of view the inside chimney is preferable.
A less desirable place to situate a chimney is
250 The Slate Roof Bible — Chapter 19 — Chimneys
The Slate Roof Bible — Chapter 19 — Chimneys 251
 REBUILDING THE TOP OF A CHIMNEY

TOOLS YOU WILL NEED: Mortar box and hoe for mixing mortar, small mortar box for use on the roof to hold the mortar (a plastic dish pan will do);
pointed masonry trowel; 5-gallon plastic buckets for carrying mortar and possibly bricks up onto the roof; brick tongs for carrying brick (optional but
recommended); 2-foot and 4-foot levels; striking tool for striking mortar joints after bricks are laid; slate ripper; slate cutter; slate hammer; flat pry
bar; small sledge hammer for knocking old top apart (may not be needed); bucket of clean water and rags for wiping chimney clean after bricks
are laid (important); tin snips; flashing (sheet metal) tongs (optional when using 16 ounce soft copper).
EQUIPMENT: Ground ladders, hook ladders, roof jacks, scaffold planks.
MATERIALS: Regular masonry cement (mortar); mason’s sand; new bricks; flashing material (16-ounce or 20-ounce soft copper or terne-coated stain-
less steel recommended); water; slates that match the roof.
MORTAR MIX RATIO: One part regular masonry cement to three parts masonry sand. Mix dry first, then add water slowly to consistency of buttery
mud.

252 The Slate Roof Bible — Chapter 19 — Chimneys

at the eaves of the building, especially if the chim- is laid. Furthermore, when building a chimney from
ney is wide, as it creates a dam on the roof which will the bottom up, make sure there is a clean-out door
eventually turn into a leak. The worst place to put a somewhere near the base of the chimney in the base-
chimney is at the eaves and at the bottom of a valley. ment and try to leave a drain in the bottom of the
This sort of chimney falls into the “roofer’s night- chimney so any rain water that accumulates down
mare” category, although they can be made there will have a place to go. Heavy downpours can
leakproof with a carefully constructed cricket. allow a lot of water to enter a chimney, even when
capped.
REBUILDING THE TOP OF A CHIMNEY When you have the bricks and tools in place
on your roof scaffold, the first batch of mortar can be
The first step in rebuilding a chimney top is mixed. It’s usually a good idea to have one person
setting up roof scaffolding. This can be easily and mixing mortar and hauling materials and another
quickly done by using hook ladders and ladder laying the bricks. The mortar is mixed according to
jacks. When the chimney is located halfway down a ratio of one part masonry cement to three parts
the roof instead of at the peak, hook ladders alone masonry sand. These materials are always mixed
with two pairs of ladder jacks (one pair above and together dry first until the mix is a uniform grey
one below the chimney) will work. If hook ladders color, then water is slowly added until the correct
can’t be used because there’s no ridge above the consistency is obtained. If the mix is too wet the
chimney, roof jacks and planks will have to do. The mortar will run all over the chimney and make a
danger of using any roof scaffold is in overloading it, mess, but if it’s too dry it will make the brick-laying
with bricks for example, and/or carelessly installing job more difficult. If it is too dry, however, a little
it. Double check everything before any weight goes water can be added while on the roof scaffold in
on the scaffold, then make sure it isn’t overloaded. order to get the mortar to the right consistency,
Once the roof scaffold has been set up, the which should be like thick pudding (or “butter” as
old chimney top should be removed and then rebuilt the contractors say).
with new bricks. Old chimney tops can usually be The mortar is first laid on the clean brick
taken apart by hand because the mortar becomes surface with a pointed trowel, then cut into two
soft after a century of weathering, although some of halves and slightly flattened with the point of the
the more stubborn chimneys may require a small trowel. The bricks are laid in place, one at a time.
sledge hammer and a flat pry bar to get the bricks After the first brick is laid, the next must be but-
apart. The top should be taken down to just below tered on the end that will abut the first brick, before
the roof line, far enough to remove all of the old setting it into place. Every course of bricks must be
flashing. All old mortar should be removed from the staggered in relation to the one below it so the joints
top of the last remaining course of bricks, then the don’t align. The courses must be checked with a
bricks brushed clean of dust in preparation for new level as they’re laid, for levelness and for plumbness.
mortar. A two-foot level can be used to plumb the first two
When a chimney top is rebuilt, it makes feet of the chimney, then a four foot level is neces-
sense to reflash it too, because it’s much easier to sary. The chimney should also be checked for
flash a chimney when rebuilding it than it is to try squareness, either by using a framing square, or by
to flash it after it’s been built. The old flashing, then, measuring the diagonals (diagonal corner to diago-
is completely removed as are the slates surrounding nal corner), which will measure exactly the same if
the chimney covering the flashing, as well as any bad the chimney is square. Smooth the excess mortar
slates (broken or tarred). It’s always easier to com- against the bricks on the inside of the chimney with
pletely clean all the bad stuff out of the way before the trowel.
beginning to put the roof and chimney back togeth- Fold the chimney flashing into the mortar
er. joints a distance of about two inches. Start with the
When building a chimney indoors, such as apron flashing, then the lower corners, which are
through an attic, run strings where the four corners folded around the corners of the chimney, then the
of the chimney will be and use them as a guide when sides. Sixteen-ounce soft copper is recommended as
laying the brick. This saves quite a bit of time flashing material because it’s long lasting and it can
because the sides don’t need to be plumbed with a be bent by hand. You’ll have to set the apron flash-
level as the chimney is built, although the courses ing in place, then lay another course of bricks
still need to be checked for levelness as each course (maybe two) on top of it, then install the corner
The Slate Roof Bible — Chapter 19 — Chimneys 253
 and the chimney will be beautiful.
Finally, after the chimney top rebuilding job
is done, you must go down into the basement of the
house and find the clean-out door at the bottom of
the chimney (and you better hope there is one —
otherwise you may have to make one). There you
will need to remove any mortar or other debris that
has fallen down the chimney when the top was
rebuilt. Otherwise you risk plugging the chimney,
and a plugged chimney is dangerous because it can
allow carbon monoxide, an odorless and lethal gas,
to accumulate in the house. If you have any doubts
about whether your chimney is venting properly,
install a carbon monoxide detector in your home,
available at most hardware stores.
One last thing — when rebuilding a chimney
top, take an extra hour or two and do a fancy job.
The extra time is well worth it when one realizes
that the new chimney top will be visible for genera-
tions.

BUILDING A FANCY TOP

DRIPSTONES
Stone shelves built into the Welsh chimney shown above
divert water away from the bottom of the chimney, acting Chimneys were often traditionally flared at
much the same as flashing. Dripstones are a common sight in the top in order to accommodate a chimney cap
Wales where both the chimney and the building are construct- stone, which was usually a single piece of sandstone
ed of similar materials.
Photo by author.
laid over the top course of bricks with a square hole
cut in the middle to allow the chimney to exhaust.
flashings, then lay a course or two of bricks, etc. This Bricks can be easily stepped out, flared, or corbeled,
is a tedious job that benefits greatly from experi- by simply adding spacer bricks in the proper cours-
ence. es. A one-inch spacer brick on every side of the
After the bricks have been laid and the mor- chimney course will space that course out 1/2 inch
tar begins to set, the joints must be struck with a on all four sides. A two-inch spacer will space the
striking tool. The joints must be struck before the course out an inch, etc. By successively increasing
mortar gets too hard, so it’s usually a good idea to the size of the spacer brick by two inches, each sub-
strike the joints as you go along. As soon as the job sequent course of bricks will be stepped out an inch
is completed (most single or double flue chimney further than the one below it. A course can be
tops can be reflashed and relaid in a day by two stepped out, then stepped back in, then stepped out
workers), the bricks should be carefully washed with again. There are an endless number of variations
clean water and a clean rag. There is no easy way to related to chimney top designs, and the design one
do this because if the mortar gets wet, it will run settles upon for his/her own work is only limited by
over the face of the bricks and make a mess, so the one’s creativity. A good chimney builder may build a
wet rag must be wrung out and carefully wiped “signature” top on his/her chimneys, such as the one
across the face of each and every brick to remove any shown on the next page.
traces of mortar. Otherwise, when the mortar dries,
it will appear as white splotches or streaks on the REMOVING AN OLD CHIMNEY
bricks and no matter how well the bricks were laid,
it will forever look bad. Once the mortar does dry Old chimneys no longer used are best
out it’s almost impossible to clean it off without removed from the roof. Once gone, they cannot leak,
using an acid solution, which is not advisable on a and they will require no further expense or upkeep.
slate roof due to the effect of the acid on the flash- They can be rebuilt if needed if they’re only
ing. Take a little extra time to carefully clean each removed to just below the roof line. Such a removal
brick when the job is done, before the mortar dries, job is routine and can be done so that the roof
254 The Slate Roof Bible — Chapter 19 — Chimneys
This old style fancy chimney top is not difficult to build, and the procedure is illustrated on the next page. Below left is
a double flue chimney on a historic house in Harrisville, PA, with an asbestos shingle roof. The original chimney was
a leaning chimney and was rebuilt plumb from the attic floor. Below middle is a rebuilt double flue chimney top, and
right is a chimney built new through a sea green slate roof. All three chimneys
are flashed with 16-ounce soft copper. (Top) A similar style on a more massive
chimney in Crediton, Devon, England.

Bottom photos by author, top photo by Dave Starkie.

The Slate Roof Bible — Chapter 19 — Chimneys 255

256 The Slate Roof Bible — Chapter 19 — Chimneys
appears never to have had a chimney at all.
The job is simple and can be briefly
described. As always, most of the job is in setting up
a safe working platform. Again, roof jacks and
planks, along with hook ladders, will be sufficient in
most cases to get the job done. Once you’ve made
your way to the chimney top, you may find that the
bricks come apart in your hand, which is common
on old chimneys. If the chimney is stubborn, a small
sledge hammer will convince it that its days have
come to an end. After the bricks are knocked apart
and the chimney is lowered enough to clear the
rafters, framing lumber is nailed to the rafters to cre-
ate a place to nail the sheathing boards that will be
patched in to cover the chimney hole. The sheathing
patch should be made of the same sort of lumber fit into a mortar joint to prevent water getting
that already exists on the roof, such as one-inch- behind the flashing.
thick boards. What’s wrong with this picture? Two things:
Sometimes a rafter is set too far from the a) on a roof, the plane is not flat, it’s sloped, and b)
chimney hole to be able to scab it out enough to nail the four corners of the column will leak because
sheathing on to it. In this case, one will have to take they’re not flashed, only the sides are flashed, leav-
a saw up on the roof and cut the old sheathing back ing a tiny gap at each corner where water can pene-
to the rafter center, then add the new sheathing trate unless the corners are either soldered or folded
nailed directly to the old rafter. A cordless circular appropriately. Corner leakage is the single most
saw is a great tool to have when removing old chim- likely problem encountered when trying to flash rec-
neys. tangular objects protruding through a roof.
When the chimney is being taken down Let’s look at the same scenario with a sloped
through the roof, the old flashing will need to be plane. Now we have an advantage, because the slop-
removed, as will the slates around the chimney, ing of the plane forces water to flow in one direction,
especially any that are tarred or broken. Bats often and because we know the direction of flow, we can
live in old chimney flashings, so keep your eyes open control the water and therefore eliminate any leak-
for them. When the chimney has been taken out of age.
the way and the mess on the roof cleaned up, there The sloping plane also adds a new factor to
will be only a hole and good slates around the spot the situation: the top edge of the flashing is no
where the original chimney used to be. Once the longer parallel to the mortar joints on the sides of
hole is closed up with the new sheathing, matching the column and cannot be folded into a joint as eas-
replacement slates are nailed in place, and the job is ily. Instead, the top of the flashing must be cut to fol-
done. low the stepped joints, and folded accordingly.
Next, we must take into consideration that
FLASHING A CHIMNEY several rows of slates are going to butt against the
side of the chimney column. Since the slates overlap
First off, no two chimneys are alike. each other, the side flashing on the chimney must be
Therefore, it is a good idea to understand the funda- cut into sections that overlap each other as well, oth-
mentals of flashing in order to understand how to erwise one long piece of side flashing would allow
flash a chimney on a roof. water to run under the edge of the slates (see illus-
Imagine, if you will, a flat plane such as a tration, page 259).
floor, and through the plane protrudes a rectangular The flashing is then installed in overlapping
column such as a chimney. The sides of the column sections and “stepped” up the side of the chimney,
can be easily flashed by simply bending long flat each step lining up with a row of slates. This is
pieces of sheet metal to ninety degree angles and fit- known as “step flashing.” To make step flashing eas-
ting them against the four sides of the column and ier to install, it is often not folded into the mortar
against the floor. If the column were an actual chim- joints at all, but instead it’s simply folded up the
ney, the top edges of the flashing would be bent and side of the chimney two or three inches, then cov-

The Slate Roof Bible — Chapter 19 — Chimneys 257

ered with “counter flashing,” which, in this case, is each corner is variable and may be made larger or
also installed in overlapping sections (the pieces of smaller according to the situation or to the personal
counterflashing overlap themselves and the step preference of the person doing the work.
flashing). Step flashing is also known as “base flash- An alternative to the folded-corner method
ing,” and counter flashing is also known as “cap of flashing involves fitting the apron flashing (the
flashing.” lowest piece on the chimney) with soldered gusset
The side flashing pieces need not be pieces, thereby eliminating any holes in the lower
installed as separate step and counter flashings, but corners. This style of flashing was once popular
can be installed as single pieces. This single side- among roofers who were involved in a lot of sheet
piece system works well when re-flashing smaller metal work, and for whom the soldering or brazing
chimneys, especially on older buildings that have of flashing was part of the normal routine. A similar
already settled. Very large brick or stone chimneys technique is the use of folded soldered seams at the
may be easier to flash using separate step and count- corners of the chimneys to provide a waterproof
er flashings. Chimneys on new construction also flashing job. This technique is often limited to the
benefit from a combination of step and counter sheet metal specialist who has proper sheet metal
flashing as the roofs will settle slightly over time tools and soldering equipment (see illustration
while the chimney will not. This causes the step below).
flashing, attached to the roof, to drop in relation to The apron flashing on the chimney is the
the counter flashing, attached to the chimney, which piece that fits at the lowermost front of the chimney.
is not a problem if the two flashings are separate. Often this is installed as two pieces, a base piece and
We have now demonstrated how to flash the a cap piece; however, one piece is often sufficient
sides of a column protruding through a sloped plane, and is easier to install, especially when reflashing an
but what about the corners? What about the top side old chimney. The apron should extend down the roof
and bottom side of the column? far enough to cover any exposed nail heads, as well
All four corners are rendered leakproof by as to provide a headlap on the second course of slate
building little “roofs” over them with folded corner below it. Four to six inches of apron flashing extend-
flashing. The bottom corners of the chimney are cov- ing down the roof is common. The apron need not
ered with the bottom piece of side flashing, and the extend beyond the sides of the chimney, although it
top corners of the chimney are covered with the can be allowed to do so and then can be laid on the
uppermost section of chimney flashing, also called roof alongside the chimney to allow a place to nail it.
the “top” or “back” flashing. In both cases this is After the apron is installed, the side pieces
simply achieved by extending the flashing beyond are installed. They should lie on the roof about four
the chimney corner about four inches, then folding inches and run up the side of the chimney 2-4” for
the flashing around the corner and tucking it into step and counter flashings, and until they reach and
the mortar joint. Extending the flashing beyond the tuck into a mortar joint for single piece flashings.
corner forces the water to flow away from the corner, Single piece side flashings should not be cut on the
while folding the flashing around the corner and ground based on drawings and measurements, but
into a mortar joint prevents water running vertical- instead should be laid against the chimney with the
ly down the outside of the 4” fold against the roof
chimney from finding its and marked in place
way into the corner. using a level and a mark-
This simple flash- er, then cut and installed.
ing technique can be used This ensures a good, tight
for any rectangle pro- fit, both against the
truding through the roof, chimney and against the
such as a skylight, and it roof. If step flashings and
requires no soldering, counter flashings are
adhesives, roof cement, used, the bottom edges of
caulk, or fancy sheet the counter flashings can
metal work. Most impor- be folded under about
tantly, if done correctly, half an inch for stiffness.
it’s foolproof. The size of The uppermost piece
the “roofs” built over of flashing on a chimney
258 The Slate Roof Bible — Chapter 19 — Chimneys
The Slate Roof Bible — Chapter 19 — Chimneys 259
 COMMON CHIMNEY REFLASHING JOB — BEFORE AND AFTER
Single flue chimneys exiting through the ridge of a roof are common, and unfortunately so are the ugly messes that are evident in the photo at
left. In about five hours a single worker cleaned up the roof and reflashed the chimney, as shown at right. The step-by-step procedure is illus-
trated on the following page.
Photos by author.

(top flashing or back flashing) is very important as it beyond the sides of the chimney about 4” and be
catches the brunt of the rain and snow (this is not folded around the chimney corner and tucked into a
found on chimneys that protrude through the peak mortar joint. In order to do this, one must allow some
of a building). A wide stock of copper should be extra flashing length where the metal is going to tuck into
used; 24” stock is usually sufficient, and need not be the mortar joint on the back of the chimney; so if you’re
run up the back of the chimney more than eight going to tuck 3/4” into the mortar joint, leave 2” of
inches (three courses of bricks). That leaves about metal instead. The extra length is trimmed off with
16” or more to run up the roof, and care should be a pair of tin snips only where the flashing tucks into
taken not to nail through this section of flashing the mortar joint, but not where it extends beyond
when laying the slate over it, except within one inch the sides of the chimney. This should leave enough
of the top edge. The roof slate should not be brought flashing material on the sides to reach around the
down tightly against the back of the chimney, rather, corner and tuck into a side mortar joint.
the flashing on the roof at the base of the chimney There are two places where hidden leaks
should be left bare for at least a few inches to allow may occur after installing top flashing on a chimney.
the water to quickly run off. It’s very important that The first can occur at the top edge of the flashing,
this flashing be folded tightly against the base of the which is under the slate, but may be exposed in the
chimney, otherwise capillary action may allow water slots because the flashing did not extend up the roof
to creep under the side wings and make its way into far enough. If so, slide extra pieces of flashing under
the chimney corners. A tight fit can be achieved by the slates at the slots, but over the flashing metal, in
over-bending the flashing to make a tight crease, order to cover the exposed edges. Secondly, the side
then opening it back up to its proper position before edges of the flashing (where the water runs off) may
laying it in place. fall on or near a slot between the underlying slates.
The top or back flashing should extend If so, reinforce the slot with flashing slid underneath

260 The Slate Roof Bible — Chapter 19 — Chimneys

The Slate Roof Bible — Chapter 19 — Chimneys 261
262 The Slate Roof Bible — Chapter 19 — Chimneys
The Slate Roof Bible — Chapter 19 — Chimneys 263
264 The Slate Roof Bible — Chapter 19 — Chimneys
The Slate Roof Bible — Chapter 19 — Chimneys 265
the slates. ry chisel for cleaning out mortar joints and for forc-
Finally, when a chimney is very wide (usual- ing in wedges to hold the flashing (when reflashing
ly over 30 inches) and creates a large dam on a roof only — new flashing is not wedged into place, it is
and therefore also creates a potentially chronic prob- simply placed into the mortar joints as the masonry
lem, a “cricket” should be installed between the top is being laid), and a two-foot level. An electric
side of the chimney and the roof. grinder with a masonry wheel or diamond blade is
Practice makes perfect. Flashing work is a very useful for cleaning out old mortar joints in
skill that benefits from practice, and the more one preparation for reflashing.
does of it, the easier it gets. Nevertheless, a person
with no prior experience should be able to flash or
reflash a chimney, although they may have to take
their time and pay close attention to detail to get it
just right. Tools required for most flashing work
include a pair of tin-snips (straight cutting aviation
snips), sheet metal hand tongs for bending the edges
that fit into the mortar joints, a thin-bladed mason-

Large chimneys, such as this massive one on a flat shingle-tile (not slate) roof on a dormitory at Grove City College, Grove City, Pennsylvania
USA, are reflashed according to the same principles as a smaller chimney. More scaffolding equipment is needed, however, to gain access to
the job site. The flashing shown here is terne-coated stainless steel, installed with counter flashings.
Photos by author.

266 The Slate Roof Bible — Chapter 19 — Chimneys

 Chapter Twenty

VALLEYS

V
alleys are sections of the roof where ed along the edges — that is, fastened with bent
two sloping planes intersect. pieces of metal (called cleats) instead of nails. It was
Typically, metal valley flashing is once recommended that valleys be cleated in place
installed over the felted sheathing before any slating for fear of expansion and contraction wearing any
begins. The felt paper is optional and can be left out nails loose along the edges, but most valleys were
completely during valley replacement jobs where nailed in place anyway, and time has shown that this
the old felt has already disintegrated. The felt paper procedure is much simpler and works just as well.
on new construction need not overlap the valley American valleys are typically laid “open,”
flashing — the valley metal can be laid right on top with approximately six inches of metal exposed. The
of the felt if it is going to be slated immediately. overall width of the valley metal can vary from 12”
Once the flashing and slate are installed, the felt will to 20” or wider, depending on the width of the
be entirely obsolete as a waterproofing material. It is exposed valley. The rule of thumb is that the slates
much more important to avoid nailing anything into must overlap the valley by a minimum of five inch-
the valley (such as felt paper) than it is to have the es, so for a six-inch exposed valley, 16” stock, or
felt paper overlap the valley metal. Before the metal wider, must be used.
is installed, a chalk line is struck up the edge of one Open valleys typically have parallel sides
side of the roof deck on the felt paper to indicate running from bottom to top, although some roofers
where the edge of the metal valley flashing should prefer open valleys that gradually widen toward the
be. The metal is then nailed in place, one side at a bottom. When laying slate into a valley, chalk a line
time, with a nail of compatible metal. The nails are the length of the valley metal on both sides to indi-
kept to within one inch of the edge of the valley cate the edges of the slate, then draw over the chalk
metal. lines with a permanent felt-tipped pen, as the chalk
Valleys don’t need to be creased on a brake, lines will wear off the metal almost immediately.
leaving them with a bend line down the center, When nailing slate over the valley metal, be careful
except in cases where the two roof surfaces are very to nail only along the edge of the metal, and not any-
steep or the valley is very narrow. Otherwise, a where near the center. If a small, triangular piece of
creased valley is simply a matter of personal style slate cannot be nailed over the valley at the end of a
and creates no advantage in the function of the val- row without nailing too close to the center, you can
ley. Instead, the valley metal can be nailed along one probably eliminate that piece of slate — chances are
edge, then carefully forced into the roof with the you won’t need it.
pressure of a knee as the other side is nailed. Valleys can also be laid “closed,” with no
Valleys should be laid in sections not to metal exposed, and “rounded” — a style more com-
exceed twelve feet in length, although a ten foot mon in Europe, in which no metal flashing need be
maximum length is recommended, due to the used at all, as is discussed later in this chapter.
adverse effect of expansion and contraction that can
cause long pieces of metal to buckle and develop a REPLACING VALLEYS
leak over time. The valley sections should simply be
overlapped by six inches — no soldering is necessary Worn out valleys on old slate roofs create one
or recommended, as it’s the old solder joints on the of the biggest problems any roof owner could have.
old valleys that tend to leak first due to expansion Valleys collect water from two or more roof planes
and contraction. Do not use roof cement or other and therefore channel a greater concentration of
adhesives along the edges of a valley, as these make water than any other part of the roof. A hole the
later repairs of the roof unpleasant and difficult diameter of a match stick in a valley can cause buck-
while adding no advantage to the functioning of the ets of water to leak into a building during heavy
roof. rains. Worse, the bottom ends of the valleys often
Furthermore, valleys do not need to be cleat- wear out first, and they also bear the greatest

The Slate Roof Bible — Chapter 20 — Valleys 267

amount of water, so serious structural water damage enough to allow access to the slates that must be
can happen to the area at the bottom of the valley if removed (about 3-4 feet back from the valley center).
left leaking and neglected for a long time. If the roof is steep, the bottom of the hook ladders
Fortunately, valley replacement is a routine will try to slide into the valley and must be tied to a
job when restoring old slate roofs. When valleys leak roof jack nailed to the roof for that purpose. If the
they should be replaced in their entirety. That valley is long, such as the 34’ length referred to
means the old valley flashing must be completely above, a 20’ hook ladder (which is the longest prac-
removed and new valley flashing installed in its tical hook ladder available) will be too short to
place. Some roofing contractors will try to slip sec- extend the entire length of the valley. Then, two lad-
tions of flashing over the old metal without remov- der sections can be bolted together end-to-end with
ing the old valley. This is a temporary solution that aluminum plates and stainless steel bolts to create a
doesn’t work very well in the long run. Others will custom-made, longer hook ladder.
tar the old valley and often the roof on the valley The bottom of a hook ladder will slide into a
sides. This is a huge mistake. Valleys can be sealed valley on a steep roof, because the slates, when
as a temporary measure to prevent leaking until removed, are stacked on the hook ladders, which
they’re replaced, and the procedure for doing so is weighs the ladder down. It also, however, makes it
illustrated on page 217; but if the job is to be done very easy to install the slates back on the roof after
correctly and permanently, the old valley must be the new valley metal has been installed, because the
removed and a new one installed. slates are waiting adjacent to where they were
In order to remove an old valley one must removed.
simply remove enough slates on both sides of the The trick-of-the-trade that makes it even
valley to completely expose the old valley metal, easier to put the roof back together is numbering the
which is usually about 14”- 20” wide overall. The slates before they’re removed. Starting at the top
metal is then pried loose and removed, the exposed row, a nail or other sharp instrument is used to
sheathing underneath swept clean with a broom, scratch the number “1” on the first row, the number
and a line is chalked for the new valley. The new being scratched on the first 4 or 5 slates out from the
metal is nailed into place, and the original slates are valley, on both sides of the valley. Then the second
replaced in the same spots from which they were row is scratched “2,” the third row “3” and so on,
taken. This is facilitated by first numbering the until the entire length of the valley is marked, row
slates before removal, as illustrated in this chapter. by row, about 4 or 5 slates out from the valley center.
Any bad slates (broken, cracked, perforated on the Mark the starter slates at the bottom with an “ST.”
face, or tarred) are simply replaced with matching This only takes a few minutes, but saves an incredi-
slates when the valley is reslated. If the slate along ble amount of time when the valley must be reslat-
the valley is in good shape, a master slater can ed. Measure the exposed width of the valley (usual-
expect to replace 34’ of valley in a 10-hour day, work- ly between 4” and 8”) and make a note of it before
ing alone. If the slate is not good (i.e. tarred and/or beginning to remove the slates.
broken), a master slater and a competent helper can Pry the ridge iron, if any, loose enough to
expect to replace a 34’ valley in a long (10 or 12 remove the nails from the cap slates underneath.
hour) day. The slates along a valley are often broken The numbered slates are then removed, starting at
because people who have attempted to repair the the top, using a slate ripper and hammer, but most-
valley in the past have walked on them; they have ly a flat pry bar, and the slates are propped on the
also spread tar all over the valley and adjacent slates, hook ladders as they’re removed. All the slates from
thereby making it very difficult to take the roof the right side of the valley must be propped on the right
apart. It’s preferable to replace a valley in a single hook ladder, and all the slates on the left side of the val-
day, if possible, as a roof should not be torn apart, ley must be propped on the left hook ladder. Do not over-
left open and subject to a potentially disastrous look this important detail if you want to put the val-
cloud burst. ley back together quickly and efficiently. Also,
remove the slates from one side of the valley at a time for
TAKING THE OLD VALLEY OUT maximum speed and efficiency (expose one entire
side of the valley before exposing the other). If two
The single most important step in removing people are working on the same valley, then both
old valleys is the roof set up. Typically, a hook ladder sides may be removed at the same time, one worker
is positioned on either side of the valley, set back far on one side and the other worker on the other side,

268 The Slate Roof Bible — Chapter 20 — Valleys

 METAL VALLEYS

• STANDARD OPEN VALLEY (above, left). Most metal valleys on slate roofs do not require a center crease, nor do they
need to be cleated into place. A standard open valley has about six inches of exposed metal, has no center crimp, and is
nailed along the edges directly through the valley metal; total width ranges from about 14” to about 20” or more, with 16”
being practical. Lengths of sections should not exceed twelve feet, with ten feet being the maximum recommended length
due to expansion and contraction issues. The ten-foot-long valley sections can simply be overlapped six inches — no sol-
dering is needed. No roof cement or adhesives are used under or over the valleys or on the slate along the valleys. No
cant strip is used alongside a valley. Some roofers prefer the exposed valley to widen toward the bottom, although this is
mostly a stylistic issue.
• CLEATED VALLEY showing an inverted “V” groove (center, left), and a center crease (center, right).Cleated valley instal-
lations are preferred by some roofers, although the cleating of valleys has been proven to be unnecessary. Flashing is
cleated in order to minimize the stress on solder joints from expansion and contraction. Valley installations typically do not
require any soldering at all, and therefore cleating is not needed. The inverted “V” groove is used when a steep roof pitch
drains onto a shallow one — the “V” prevents water from forcing its way under the slates on the shallow side. A center
crease is preferable in closed valleys, or very narrow valleys, or on very steep slopes, or it can be added simply for style.
• CLOSED VALLEYS (above, right) show no exposed metal in the valley, since the slates butt against each other in the
valley center. Typically, they are installed with step flashing. The bottom of the step flashing lines up with the bottom of the
overlying slate; the top of the step flashing lines up with the top of the underlying slate. The top of the step flashing may
extend above the underlying slate for nailing purposes.

QUICK REFERENCE - VALLEY INSTALLATION

Make sure the board roof sheathing is covered with 30 lb. felt paper. The felt does not need to be overlapping the
valley if the valley is to be slated immediately (the valley metal can be installed directly on top of the felt). Run a chalk line
up one side of the valley felt to indicate where the flashing metal should be positioned. For example, for 16”-wide valley flash-
ing, measure approximately 8” on the roof from the valley center and chalk a line parallel to the length of the valley.Use 16-
or 20-ounce copper, or stainless steel (18 gauge or heavier) sheet metal, 16 inches wide for a six-inch exposed valley, 18-
20 inches wide for an eight-inch exposed valley (more common on churches and institutions). The rule of thumb is that the
slates must overlap the valley metal by at least five inches, and that the valley flashing should only be nailed within an inch
of its outer edges.
Valley flashing typically does not need to be cleated, crimped or creased, but should have an inverted V groove one
inch high if a steep roof slope is running into a shallow one. The valley metal should have a center crease if the valley is
especially narrow or on a very steep roof, or closed. Lay the valley metal onto the roof, carefully forcing it into place using
your knee (if the metal has not been creased on a brake — if creased, it will lay into the valley easily), and then nail within
1” of the edges of the metal, using nails of compatible metal. Nail one side into place first, then the other. Keep metal valley
sections to a maximum length of 10’, overlapping 6” at ends; don’t use roof cement or adhesives. Chalk lines the length of
the valley flashing to indicate where the edges of the slates will be (3” out from the center of the metal for a 6” exposed val-
ley), then immediately draw over the chalk lines with a permanent felt-tipped marker as the chalk will quickly rub off. The
drawn lines will act as guides for the exposed edges of the valley slates. Leave six inches of metal exposed for a standard
open valley; chalk lines at a slight angle to create an open valley that widens near the bottom, if desired. After valley metal
is in place, chalk remainder of the roof horizontally for the slates, if needed, chalking over and onto the valley metal. When
nailing slates over the valley metal, hold nails back to within an inch of the edge of the metal if at all possible.

The Slate Roof Bible — Chapter 20 — Valleys 269

 Valleys are flashed differently
under different situations.
Symmetrical valleys (A)
require no special metal work.
A steep roof plane draining
against a shallow one (B)
should have a valley with a
center “V” crimp. Large differ-
ences in slopes (C) may
require a water stop.

s CLOSED VALLEY - Slates are butted against each

other in the middle of the valley (see opposite page).

Photo by Adam Bossert.

t Roof jacks (brackets) are used to stack slates

on when a hook ladder can’t be used.
Photo by author.

270 The Slate Roof Bible — Chapter 20 — Valleys

The Slate Roof Bible — Chapter 20 — Valleys 271
Slates are removed from either side of this 20’-long valley on a house After the new metal is installed (in this case, 20-ounce half-hard cop-
in Sandy Lake, PA, and propped on the hook ladders, which are pre- per), the numbered slates are nailed back in place, and any bad
vented from sliding into the valley by a roof jack tied to the ladder. slates are replaced in the process.
Photos by author.

one above the other. down the roof starting at the top, and drop it over
If the slates have been tarred into place, try the edge, if possible. Then sweep the roof clean with
to carefully pry them loose without breaking them. a broom, and examine it closely for nails and any
In some cases you may have to cut along the tarred sharp objects that might rub against the new flash-
valley edge with a utility knife to get the slates to ing and eventually penetrate it. Use a gloved hand
come loose in one piece. Heavily tarred slates that and brush it over the roof boards — it will catch on
can be pried loose can usually be cleaned of most of any sharp nub. Pound the nub in or pull it out with
the tar and re-used. The tar is knocked off by tap- a claw hammer. When you’re sure you have the old
ping directly against the edge of the slate with a sheathing clean, chalk a line on one side of the val-
hammer, or by using the tip of a slate ripper or flat ley to indicate where the edge of the new metal will
pry bar to chip it off. be. If the new metal is 16” wide (for example), snap
If you cannot place a hook ladder on either your chalk line at 8” from the center of the valley.
side of the valley because there isn’t a ridge to hook Often there will be a small spot on the
onto, then you must nail roof jacks to the roof and sheathing that has rotted due to a prolonged leak. If
prop the slates on them (see Chapter 12 for instruc- the new flashing is going to cover it, don’t worry
tions on nailing roofs jacks). Again, the slates from about it — put the new metal in right over top of it.
one side of the valley must be propped on that side It’s very rare that sheathing in a valley will be so bad
of the roof. that it needs to be replaced. It’s more important that
Once all the slates are removed and the old the valley be replaced and the roof be closed up as
valley flashing is completely exposed, the old metal quickly as possible, so minor imperfections in the
can be pried out with the flat pry bar. This is a seri- valley boards can be tolerated. They’ll do no harm.
ously dirty job, and a dust mask is a good idea when
taking out old valleys. Also, be on the lookout for
wasp nests underneath the bottom of the old valley
when you roll it out. Pry the old metal loose, roll it
272 The Slate Roof Bible — Chapter 20 — Valleys
Umberto Perlino, a slate roofing contractor in Pennsylvania, works at replacing a 34’-long valley on a white oak lath-roofed barn. Although the
old terne metal valley was completely deteriorated and the valley slates were tarred and broken, this replacement job was a day’s work for a
master slater and a helper. Notice that there is no felt underlayment on this 100-year-old roof. There never was. The repaired roof is 100%
leakproof. Felt paper is totally unnecessary for the proper functioning of most slate roofs.
Photo by author.

The Slate Roof Bible — Chapter 20 — Valleys 273

274 The Slate Roof Bible — Chapter 20 — Valleys
s Hook ladders are positioned alongside this s The slates are pried off, stacked on the s A 12’ section of .025” stainless steel, 16”
34’-long church valley. The valley was tarred, hook ladders, and the old valley metal wide, is forced into place and nailed along
but the sea green slate was quite good. removed. The roof is swept and chalked. the edges, aligned with the chalk line.

s A second section of stainless over laps the s The third and final section of stainless is s The slates are nailed back where they
first by 6”. 10’ lengths are preferable, 12’ is installed. came from. The new valley should last the
maximum. life of the roof and require no maintenance.

General Valley Replacement Sequence

Opposite page: 1) The slate rows are numbered by scratching with a nail. 2) Hook ladders make the job easy.
Slates are pried from each side of the valley and placed on the adjacent hook ladder. The original felt may be dried
up and no longer functioning as a waterproof barrier. 3) The metal is completely removed, and the exposed wood
deck is swept clean (wear a face mask). All protruding nails are removed or pounded down. 4) The wood is chalked
for the new flashing. There is no need to install felt or any underlayment under the new metal — you can simply
nail it directly to the wood with compatible metal nails (no side cleating of the valley metal is necessary either). 5)
The numbered slates can then be replaced in their original positions. Broken slates are replaced with reclaimed
slates matching in size, shape and type (color). The finished job is permanently waterproof and looks good.
Virtually any valley can be replaced in a single day by experienced slaters. The church valley above was a 10-hour
job for one experienced slate roof restoration professional. The stainless steel had been pre-drilled and almost all
of the slates were good enough to be reused.
Photos by author.

The Slate Roof Bible — Chapter 20 — Valleys 275

s A carefully placed knee forces valley metal into position without buckling it (above left). After nailing the valley in place, one side is re-slat-
ed first while working off the bare roof (above, middle). Then the hook ladder (now empty) on that side can be moved in close to the valley to
sit on while slating the other side, thereby avoiding damaging the newly replaced slate. Top photo at right shows finished valley. Center photo
shows one side slated (the left side).
Photos by author.

INSTALLING THE NEW VALLEY FLASHING harm. Twelve-foot-long valleys may be necessary in
some very unusual instances but twelve feet should
When laying the new metal in place, remem- be the limit. The sections should be overlapped six
ber that it doesn’t have to be creased down the cen- inches in the direction of water flow. One side of the
ter on a sheet metal brake, nor does it have to be valley should be nailed first along its entire length
“cleated” in place. Instead, the metal can simply be (the chalked side), then one end forced into place
carefully forced into the contour of the valley into a (usually with a knee) and nailed, then the other. The
rounded valley shape. This won’t work, however, if end you want to have the tightest fit — usually the
the exposed valley is too narrow (under 4”) or on a bottom end because it is visible from the ground —
very steep roof (such as valleys on some dormers or should be forced in and nailed last. Be very careful
on mansard roofs)— then the valley needs to be when forcing a copper valley into place, as too much
creased. However, narrow valleys on steep roofs are force can cause the soft metal to kink. However, get
uncommon, and ninety-nine times out of a hundred the valley metal to conform to the shape of the roof
a force-fit valley works fine. as tightly as possible without improperly bending it.
One disadvantage of using creased valleys When replacing two valleys that converge at
lies in the fact that old valleys on old roofs are often the top (a common situation), carefully fold the tops
not straight. Over the years the roof may have settled over each other at the ridge. This can be done with-
or even bowed a bit. Creased valley metal is stub- out the need for solder, although a little lifetime sil-
bornly straight and may not form to the contour of icon under the metal in a couple of critical spots
the roof. This presents a problem that can only be doesn’t hurt. Caulk or no caulk, a properly folded
solved by cutting the creased valley metal into short- valley top will not leak. Remember that there will
er lengths, or by using non-creased valley stock. One probably be a segment of ridge slate or metal that
advantage to using creased valley stock, on the other will cover some of that valley top and keep the rain
hand, is that the valley metal lies down tight against out. What doesn’t fold over the ridge will lay flat on
the roof boards, preventing birds and other nui- the roof and should also be overlapped. If there is
sances from creeping under the metal and establish- not adequate overlap, an extra piece of metal can be
ing nests. installed at the top convergence of the valleys to
It’s important to remember that the valley make it leak proof before it is re-slated. Practice
metal should not be laid in lengths longer than makes perfect.
about ten feet due to possible expansion and con- The bottom of the valley usually has to be
traction of the metal and consequent long-term cut to conform to the corner of the roof, leaving

276 The Slate Roof Bible — Chapter 20 — Valleys

enough overhang to channel the water into the gut- valley, although it will not be visible from the
ter. If you’re not sure how much overhang to leave, ground at any time). When re-slating, align the inside
better to leave too much — it can be trimmed off or edges of the slates with those ink lines, and don’t worry
bent over later. Make sure the valley metal is under about the outer sides of the slates being exactly paral-
the shim or cant strip at the drip edge and not on top lel to each other if you want the valley to look neat.
of it (assuming a shim strip exists). Keep the shim
well back from the valley center — it need only over- RESLATING THE VALLEY
lap the valley metal an inch or two. The bottom of
the valley metal at the drip edge can also be folded When reslating the valley, start at the bot-
down about an inch to create its own drip edge, tom. Use the same slates that were removed from the
thereby preventing capillary attraction up the valley roof as much as possible, for two reasons. First,
bottom as well as obstructing birds and other they’ll match that roof better than any other slates
unwanted visitors who may try to crawl under the because they came from that roof. Secondly, they
valley metal after installation. have weather marks on them showing where they
Some roofers insist upon installing felt were overlapped by the other slates, and can there-
paper under replacement valley metal. Others insist fore be placed back in the same spot they came from
(religiously) upon installing self-adhesive underlay- by simply lining up the weather marks with the
ment under all valley metal. The author is not a big slates already on the roof. With numbered slates
fan of self-adhesive underlayment as the metal can positioned on the proper sides of the valley, and
stick to it, thereby inhibiting expansion and contrac- weather marks to guide you, you can zipper a valley
tion; plus, it’s an unnecessary material which eats up back together in less time than you may think.
time and money, both paid for by the property When you start reslating at the bottom of the
owner. Felt paper under a replacement valley does- valley, make sure you have a piece of wood shim (or
n’t hurt anything, and may even act as a cushion for cant) in place under the starter slates, about 1/2”-
the valley metal. Nevertheless, when replacing val- 5/8” thick (for standard thickness slates) and an
leys, the valley metal can usually be laid directly on inch or so wide, positioned right at the bottom of the
the cleaned bare wood with no ill effect. The original sheathing (see Chapter13). If the original cant strip
felt paper is typically dried up and non-functional is still there and is usable, fine. The cant strip lies on
by that time anyway, and the contact the valley top of the valley metal, but should not extend into
metal has against the bare roof deck does not harm the center of the valley as far as the slate, and usual-
it in any way. There is no reason to believe that felt ly need not extend over the valley metal very far at all.
paper under valley metal will prolong the life of the When re-slating, simply nail the slates back
valley, although the felt can act as a nominal insulat- into place in the same spots from which they were
ing thermal barrier where one is needed. More often removed — one side of the valley at a time, if working
than not, roofing contractors rely on underlayment alone. If two people are reslating a valley at the same
to conceal shoddy workmanship. If they think their time, both sides can be reslated at once with one per-
valley job will leak, they pour on the underlayment son working above the other. If working alone, after
before installing it. A properly installed valley will one side has been reslated, slide the hook ladder
not leak, underlayment or no underlayment. from the finished side closer to the valley center and
Once the valley metal has been installed on work off the repositioned ladder while slating the
the roof, you must chalk a line up either side of the other side. Be careful that the foot of the hook lad-
metal to indicate where the edges of the slate will be. der is not digging into the valley metal.
Some foresight is necessary here, and although most You’ll find that many of the slates you’re
valleys have parallel exposed edges, not all exposed nailing back into place will be covered on one side
valleys are the same width. Six inches is average for by a nailed overlying slate, and therefore the
an open valley, but they’ll vary from 4” to 8” or 10” replacement slate can be nailed only on one side.
if open, or they may be closed instead. If the original Punch an extra hole with a slate hammer on the
valley exposure was 6” wide, measure 3” from the exposed side a few inches above the existing hole so
center on both sides and chalk two lines the length that you nail every slate with two nails. If the old
of the valley on the metal, 6” apart. Then immedi- nail holes are still good, use them, if not, punch new
ately go over those lines with a permanent felt tip ones near the outer edge of the slate. Make sure your
marker, pushing the chalk out of the way with the nails are 1 1/2 inches long (for standard thickness
felt tip as you go (the ink will eventually wear off the slates). Occasionally, you’ll run into a slate that

The Slate Roof Bible — Chapter 20 — Valleys 277

 Narrow tongue in
groove boards were
originally used to
round the valleys at
Glenridge Hall in
Sandy Springs, Rounded and Swept Valleys
Georgia (left). When
reslated, 20 ounce
copper strips were
laid in with each
course of valley
slates to ensure a
water tight installation
(right). Alternatively,
longer valley slates
with double headlap
can be used (top
right), or the valley
slates can be
installed with twice as
many courses as the
field slates (pages
281-282).

Photos this page by Ron Stokes.

278 The Slate Roof Bible — Chapter 20 — Valleys

 SLATED VALLEYS
What you can’t see: Valley boards underneath the valley
slates extend above the ridge and meet in the center, creat-
ing a sweeping curve where the gable ridge meets the main
roof at the top of the valleys. The valley board is completely
hidden in these photos, of course, as is the fact that the val-
ley slates are longer than the slates on the main roof.

The valleys shown at left and at top left have hidden copper
step flashings installed under each course of valley slates.
The slates in these valleys are six inches wide.

Photos by author.

The Slate Roof Bible — Chapter 20 — Valleys 279

slides into place and has no exposed side on which the slates and the slope of the roof, although a width
to nail. Nail it with the nail and bib technique that of 9” to 11” seems to be most effective.
is described in Chapter 17, or use a slate hook, if
possible. Cut replacement slates as you need them EXTRA HEADLAP
with a slate cutter, and always use matching slates.
Make your cuts right there in the valley; don’t go The slates in the valley must be longer than
down onto the ground to cut the slates. the standard slates on the roof if step flashing is not
Be very careful when using soft copper valley being used in the valley. The headlap should extend
flashing to not drop any sharp object on the valley not just three inches under the second overlying
metal. Soft copper punctures easily, and a dropped course, which is standard headlap; it should extend
slate hammer or ripper (or slate) can punch a hole in completely up to and under the third overlying
it. Furthermore, be careful when working over a soft course by an inch or so. The extra headlap is neces-
copper valley. If you sit or stand on it and put too sary to prevent water penetration since the valleys
much weight on it in the wrong way, you can perma- carry more water and have a lower slope than the
nently buckle it. Stainless steel valleys and heavy rest of the roof.
aluminum (.040”) are much stronger than soft cop-
per and can take a lot more punishment. Partially ROOF SLOPE, VALLEY LENGTH,
hardened copper is preferable to soft copper in val- AND OTHER CONSIDERATIONS
leys, and one of the best valley flashings available is
20-ounce half-hard copper. Slated valleys cannot be installed on low
slope roofs. It is recommended that slated valleys be
ROUNDED VALLEYS installed on roofs with slopes no lower than 300
(7:12), although much steeper slopes, such as 20:12,
Perhaps the most aesthetically appealing of are recommended.
all valleys are those made of slate with no exposed The longer the valley, the more water it must
metal. These are generally referred to as rounded or carry, especially at the bottom. Therefore it is not
slated valleys and they exist in many different styles. recommended that rounded valleys be designed on
Some rounded valleys utilize valley slates of uni- long runs, with 20’ being a recommended maximum
form sizes, others are completely random. The vari- length. Also, regardless of valley length, some val-
ous styles of slated valleys are illustrated in some leys may be subjected to a great amount of water
European texts, such as Architecture and Techniques of flow due to the size of the roof surfaces that drain
Slate Roofing, by Jose Luis Menendez Seigas, and into the valley. This must also be taken into consid-
others. eration when designing a rounded valley. If the
Slated valleys can be found on very old water flow or other characteristics of the roof cast
buildings in Europe. They were probably first devel- some doubt on the efficacy of a rounded valley
oped in order to avoid the use of metal on the roof, installation, hidden flashings may be installed
as suitable metal flashings may have been hard to between the valley slate courses.
obtain a couple hundred years ago. It is reported,
therefore, that valleys can be constructed utilizing HIDDEN FLASHINGS
slate only and no metal, although slated valleys can
also employ hidden metal step flashings. Rounded slate valleys may have a piece of
step flashing installed between each course of valley
VALLEY BOARD slates. This can overcome problems associated with
valley slates that are too short, slopes that are too
There are a few primary differences between shallow, or roofs that are too large and drain too
open metal valleys and rounded valleys. The first is much water. Some contractors install hidden flash-
the valley board, which is a board that runs parallel ings in rounded valleys as a matter of course, no
to the valley up its center, used on rounded valleys matter what. This hidden flashing can be copper,
but not on other standard open valleys. This board stainless steel (preferably terne-coated in order to
may have an additional tapered board on either side dull it down), lead or zinc. This is illustrated on
of the valley board (a “fairing strip”) in order to help page 278.
round the valley smoothly. The width of the valley
board can vary somewhat depending on the size of

280 The Slate Roof Bible — Chapter 20 — Valleys

 Photos by author.

The Slate Roof Bible — Chapter 20 — Valleys 281

 Photos by author.

282 The Slate Roof Bible — Chapter 20 — Valleys

 Chapter Twenty-One

CLAY TILE ROOFS, ASBESTOS ROOFS, FLAT SEAM COPPER ROOFS

AND MISC. ROOFING

C
eramic tile roofs are mentioned here
because slate roofers are often called
upon to repair old tile roofs, and
sometimes tile roofs are confused with slate roofs by
their owners. Many tile roofs are similar to slate
roofs in that the tiles are semi-permanent, they’re on
steep roofs, some are shaped like slates and even
look like slates, and their repairs require basically
the same tools, equipment and procedures as those
used on slate roofs, with some notable exceptions.
These include the cutting of the tiles, as a slate cut-
ter will not cut a ceramic tile and a diamond blade
saw must be used instead, or a special hand-operat-
ed tile cutter must be used, several varieties of which
are available in Europe. Tiles cannot be punched for
nail holes like slate can — they must be drilled with
a masonry drill bit. Also, it is common to hang some
tiles in place using copper wires during specific
applications, such as along valleys during replace-
ment of the valley metal. Finally, individual tiles,
when replaced in the field of the roof, are rehung
using special tile hangers, which wire to the back of
the tile. Neither slate hooks nor nails and bibs are
used with ceramic tiles.
Clay tiles fall into two general categories:
flat or shingle tiles, and rounded or pan tiles. There
are many, many different types and styles of clay

This technique for replacing

tiles on a roof will work for just
about any shape or type of tile,
including Spanish tiles. The tile
hanger is simply custom-made
to suit the tile being replaced,
some longer, some shorter,
some wider, some narrower.

The old tile is pulled out using

a slate ripper. Although it is
common in some roofing cir-
cles to use exposed strap
hangers to replace clay tiles,
these are unsightly and should
be avoided. Any finished repair
should be invisible.

The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc. 283
 Shingle tile roofs are similar to slate roofs, and replacement of a val-
ley follows similar steps. First the tiles are removed from either side
of the valley using a slate ripper. Before removal they’re numbered by
scratching with a nail. The tiles from each side of the valley are
propped on hook ladders situated on the same side of the valley.
Once the tiles are off, the old valley metal removed, and the valley
swept out, new metal is installed as shown at left (#1) where terne-
coated stainless steel is being used. Once the metal is installed, the
valley is re-tiled, starting on one side with the starter tile (#2). Note
that the small triangular tile in the valley center is hung on a piece of
copper wire and glued in position with clear silicon caulk for added
anchoring. The next course of tiles is then installed (#3) in the same
manner. A tile hanger is wired to the back of the tile (bottom left)
when there is no way to nail the tile in place.
Photos both pages by author.

284 The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc.
 The courses of tiles are continued in the same manner using
tile hangers, copper nails, and copper wires, up one side of
the valley (#4) until that side is completely tiled back in. Then
the other side is tiled. Both sides can be tiled at the same time
if two men are working on it together; however there is an
advantage to having one man simply wiring tile hangers to the
back of tiles as the other is installing them (#5). Nails used to
install these tiles were 2.5” copper roofing nails.

The photo at the bottom left shows the same procedure being
used on an interlocking shingle tile roof where a 20-ounce
copper valley is being installed. The tile hangers used on this
roof are a different size (longer) in order for the tiles to be
positioned correctly once re-installed. A wire attached to a
copper nail holds the small triangular piece of tile in the cen-
ter of the valley (circled).

For more information about tile roofs see Hobson, Vincent H., 2001, Historic
and Obsolete Roofing Tile, Remai Publishing Company, Inc., Evergreen,
Colorado, USA; www.rooftilebook.com

The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc. 285
tiles in existence. Any proper repair work on a tile ASBESTOS ROOFS
roof requires the availability of matching replace-
ment tiles, which may be hard to find when working Asbestos roofs are mentioned here because
on an old tile roof. Fortunately, there are several roof people who have this type of roof on their buildings
tile salvage services available in the U.S. (listed in often mistake them for slate. Some even call them
the back of this book), and these will help you find “asbestos slate” roofs. Asbestos roofing is a human-
the tiles you need. made material consisting of asbestos fibers and a
As always, when working on a roof with binding agent. It does not have the characteristics of
unusual clay tiles, slates or asbestos tiles, and suit- natural slate roofing, although it can resemble slate
able replacement tiles cannot be found, it is advis- in appearance, especially to the layperson. Like slate
able to cannibalize a section of the roof and use the roofs, asbestos roofs tend to be old, and it can be dif-
shingles taken from that section to repair the rest of ficult to find someone to repair them. One complica-
the roof. This means removing a section of the roof tion associated with asbestos roofs is the fact that
in a relatively invisible area, such as one half of a asbestos is now considered a toxic material because
rear dormer roof, using the tiles removed to repair it can cause lung cancer if inhaled, and therefore the
the remainder of the roof, then re-tiling the canni- removal of asbestos roofing is expected to be done by
balized area with another tile that does not match toxic waste professionals.
perfectly, but is close enough. This strategy will save The bright side of this dilemma is that
many a roof while maintaining the aesthetic integri- asbestos roofs can be maintained for quite some time
ty of the roof overall. as long as replacement shingles are available to replace
The proper way to replace a ceramic tile in any that become broken. If replacement shingles are
the field of the roof is to carefully remove the broken not available, then use the “cannibal” method
tile with a ripper, then wire a copper or stainless described above to get the shingles you need.
steel tile hanger to the back of the replacement tile, Asbestos roofs can be maintained much the
then slide the replacement tile into place, hooking same as slate roofs are maintained — with hook lad-
the tile hanger to the tiles underneath the replace- ders to work on the roof, slate rippers to remove the
ment tile. Visible strap hangers should never be old tiles, and slate cutters to cut them. Asbestos roof-
used. ing cannot be punched with a slate hammer, but it

286 The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc.
 ASBESTOS ROOFING

Much of the old American asbestos roofing is laid up in the diamond

pattern shown at right. A half-inch square piece of flat copper with a
pin sits under two overlying shingles, and the pin feeds through a
hole in the bottom of the top shingle and bends over to secure it.
The top of the shingle is nailed in two places with copper nails. To
replace a broken tile, unhook the pin and then pull the two nails out
with a slate ripper. Replace the tile with a new one by fastening the
new tile in place with stainless steel slate hooks positioned at rough-
ly 4 o’clock and 8 o’ clock on the new tile (as shown on previous
page).

can be drilled, or punched with a slate cutter that regularly after about 50 years of age if copper. These
has a hole punch on it. Asbestos shingles are often roofs differ from “standing seam” roofs, which have
laid in diamond patterns and have no overlying slot, an obvious metal seam that projects vertically an
so replacing them usually requires a couple of slate inch or so, running the length of each metal roofing
hooks. panel. It’s the soldered-seam roofs that are most com-
The original asbestos shingles are nailed monly associated with old slate roofs.
with two nails, and the diamond patterned ones also The reason they’re mentioned here is
have a copper clip through the bottom. Sources of because they’re a maintenance problem for many
asbestos tiles have been listed at jenkinsslate.com. owners of old slate roofs, since the metal is often run
up under the slates where the flat roof abuts the slate
BOX GUTTERS roof. If you have a slate roof with a soldered-seam
roof associated with it, there are two things you
Box gutters are very common on buildings should know. First, terne metal soldered-seam roofs
that have old slate roofs. These gutters, like sol- should be kept painted with tinner’s red oxide paint
dered-seam or flat-seam metal roofs, were typically (or any good, exterior metal paint). If not, they’ll
made from soldered terne metal. They rust and cor- rust and start leaking, usually at the seams. Second,
rode when not kept properly cleaned and painted, if the soldered-seam roof is already leaking because
and many of these old gutters leak. They can be the roof has long been neglected and now you have
replaced, however, by carefully measuring the wood- to do something about it, the roof can be replaced
en frame holding the gutter, then having a new with new metal. There is also an easy and effective
metal liner fabricated at a local sheet metal shop in temporary remedy: liquid asphalt emulsion and fiber-
4-, 8-, 10-, or 12-foot lengths. Use terne-coated stain- glass membrane.
less, 20-ounce copper, or another metal that won’t Liquid asphalt emulsion is an old-fashioned
corrode, overlap the metal sections by an inch and a roofing material that works well to preserve old
half or two inches, rivet the pieces together with metal roofs when paint won’t do. It’s a water-based
stainless steel or copper rivets, then solder the joints (emulsified) asphalt that must be applied when no
and the rivets (see illustrations, next page). rain is imminent as it will wash off if it is subjected
to a downpour before it sets up. But once it dries it’s
SOLDERED-SEAM METAL ROOFS insoluble in just about everything, and you’ll soon
be a believer when you try to wash dry asphalt emul-
Many old slate roofs have low-slope soldered sion off your hands or clothes with water, gasoline,
seam metal roofs abutting or adjoining them. or anything else after applying it to a roof. Liquid
They’re usually found on porches, bay windows, and asphalt emulsion comes in five gallon buckets and is
two-story additions. These roofs are usually made of applied with a long-handled roofing brush. It’s lib-
terne metal panels, and sometimes copper panels, erally brushed onto a clean, dry surface (like paint-
soldered at their flat-lock seams, hence the name ed or rusted metal), then a layer of fiberglass mem-
“soldered-seam,” “flat-seam,” or “flat-lock” roofs. brane (which is made in rolls to be used with the
They’re excellent, long-lasting roofs if they’re proper- emulsion) is carefully rolled out over the wet asphalt
ly maintained — most aren’t. Proper maintenance and brushed in, then a second liberal coat of asphalt
means painting regularly if terne metal, or painting is applied over top of the fiberglass. The fiberglass
The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc. 287
288 The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc.
comes in rolls of various widths, and the three-foot- 288). The field of the roof is then covered with metal
wide roll is most practical for larger surfaces. The pans which can be various standard sizes, the most
whole thing needs to set up overnight, and maybe common perhaps today is a panel 24” X 18”. Old
longer if the weather is cool or humid Then, a third, roofing books describe these standard panels as
final coat of asphalt is applied right over top of the being 10” X 14” or 10” X 20” (Roofing, 1930); 20” X
whole shebang. 28” (Sheet Metal Workers’ Manual, 1942, and
When all is dry and done, the metal has a Architectural Sheet Metal Manual, 1993); 14” X 20”
thin coating of black asphalt (which can be painted up to 20” X 28” (Roofing Construction and
to change the color, if desired) that remains hard Estimating, 1995); 14” X 20” (Standard Practice in
even in hot weather, and can be walked on. When Sheet Metal Work, 1929); and 18” X 24” maximum
the asphalt wears thin a number of years later, brush (Copper Development Association, 1991). So obvi-
on another coat and throw in some fiberglass over ously the particulars of flat-seam roofing are not
any weak areas. Be very careful not to apply asphalt carved in stone.
over any slates — brush it up under the slates when The flat pans are cut, the corners are
you’re coating a metal roof that abuts a slate roof, snipped off at approximately a forty-five-degree
and make sure the fiberglass is worked up under the angle, then two adjacent edges are folded up and the
slate with a pointed trowel, if necessary. opposite two adjacent edges are folded down, the
Liquid asphalt emulsion will seal up your folds being 1/2” to 3/4”. The pans are fastened to the
soldered-seam roof so it won’t leak, and at a reason- roof with cleats, these being made of the same metal,
able cost. An alternative covering for old soldered- approximately 1.5” X 2”, with a fold equal to the
seam roofs that is gaining popularity is rubber roof- folded seam on the pan (1/2” to 3/4”). This fold is fit
ing. The problem with rubber roofing is that the into the pan seam, and the other end is nailed to the
rubber must also be worked up under the slates, and roof deck with two nails, then folded over the nail
most rubber roof guys just slap it over top of the heads. Two to three cleats are recommended on the
slate and glue it down. This creates big problems long side of the pan and one to two cleats on the
when the glue lets loose — and it will. Then try to short side. The seam is then hammered down with a
find your rubber roof guy to come back and repair it dead blow hammer and soldered with 50/50 tin/lead
(good luck). Properly done, a rubber roof abutting a solder or other suitable solder. Roof protrusions
slate roof requires that the slates are lifted, the rub- such as vent pipes are fit closely around the base
ber installed underneath, then the slates are relaid. with a pan, then a sleeve is fabricated with a flared
Liquid asphalt emulsion is cheaper, easier to work bottom that is riveted to the pan and soldered in
with, available at most roofing supply outlets, and place.
do-able for most do-it-your-selfers. But watch out —
it’s messy! ROOF ACCESSORIES
The best way to repair a leaking soldered-
seam metal roof is the same way flashings are SNOW GUARDS
repaired on slate roofs: the old metal is completely
removed and then replaced. When the old terne Snow guards are small, angled metal brack-
metal is removed, it should be replaced with new ets permanently attached to the roof to prevent ice
terne-coated stainless steel or 20-ounce copper. 16- and snow from cascading off the roof in an ava-
ounce copper will work too, but for the smaller extra lanche. They fall into two primary categories: those
cost and the promise of a metal roof that can last a that are nailed to the roof, and those that hook either
century with little maintenance, the 20-ounce cop- on the slates themselves, or on the slate nails. The
per would be preferable (and the stainless the most ones that are nailed on must be installed when the
durable). It has become difficult these days to find roof is installed. Otherwise, slates must be removed
roofing contractors who can and will do flat seam from the roof, the snow guards attached, then the
metal roof work. Some instructions are illustrated slates replaced. On the other hand, the kind that
on the following page, and the reader is advised to hook on an existing slate or nail may be attached to
check jenkinsslate.com for the possible availability the roof at any time with much less effort. Some sim-
of more detailed video and/or print instructions. ply have a long, slotted end which is slid up under
The flat-seam roof starts with a drip edge the slate as if it were a slate ripper, and hooked on a
almost exactly the same as the drip edge shown here slate nail. Others are slid between the slightly lifted
in the box gutter replacement illustration (page slates until they hook over the top. The snow guard,

The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc. 289
 Typical pans are 18” X 24” (shear size) with a 1/2” to 3/4” fold on the edges.
Cleats are approximately 1.5” wide X 2” long and nailed with two nails each.
Pans are installed over a felt paper base covered by rosin paper (the rosin paper
is directly under the roof metal). The seams are hammered down with a dead-
blow hammer, fluxed, then soldered with 50/50 tin/lead or other suitable solder.
Edges should be pre-tinned for easier soldering, especially on slopes and verti-
cal surfaces. After sweating the seam, a final pass with solder to “bridge” or
“stitch” over the joint until the seam is no longer visible finishes the job.
Expanses over 30’ require expansion joints.

Keep your weight on the panel when

cleating it into position. Flush with water
and baking soda after soldering.

Apply a 30-pound felt underlayment over the

roof deck, then a layer of 4-6 lbs./square of
rosin sized building paper (slip sheet) directly
underneath the metal.

Flat-Lock Soldered Seam Metal Roofing

Corner is snipped off at

approximately a 45-degree
angle before folding.

Pans are cut (e.g. 18”X24”), then the corners are snipped off at approximately a 45-degree angle so when the edges are folded there is 1/8”
to 1/4” clearance between the folded mitered corners. The edges are then folded, two adjacent edges folded one way and the opposite two
adjacent edges folded the other.

Check jenkinsslate.com for the availability of an instructional video on flat-lock copper roofing.

290 The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc.
20-ounce flat-lock copper with 18” X 24” pans being installed on a Vermont unfading-green slate roof in New Jersey by Barry
Smith Slate Roof Restoration (above). Top left photo shows pans before soldering. Barry Smith installs a terne-coated stain-
less steel flat-lock roof adjacent to a New York red slate roof located in Troy, PA (below). Top photos by Barry Smith, bottom photo by Aaron Cable.

once hooked, is left in place. the problem. Lightning rods are designed to divert
Snow guards are positioned above doorways, electric current away from a building by channeling
walkways, porches, sidewalks and anywhere where the current through a heavy copper or aluminum
falling ice or snow may present a hazard. They’re cable into the ground. Therefore, a lightning rod
made of either galvanized steel, painted steel, stain- must be properly grounded or it won’t work at all.
less steel, copper, aluminum or bronze, and may be Many older homes with old lightning rod systems
lead coated. Some are available as “snow railings,” are now having the rods and cables removed.
an elongated version of the snow guard. Sources of snow guards and lightning rods
are listed on the following page.
LIGHTNING RODS

Lightning rods are common on old slate

roofs. They’re often nailed onto the roof right
through the slate, usually with rather large (i.e. 16
penny) nails, and the nail heads are caulked or
cemented to prevent leakage. The feet of old light-
ning rods will sometimes cause leaks because the
cement over the nails has worn away, and a fresh
application of roof cement or silicon caulk will cure
The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc. 291
 SOURCES OF SNOW GUARDS

• Berger Building Products — 805 Pennsylvania Boulevard, Feasterville, PA 19053; Ph: 1-800-523-8852 or (215) 355-
1200; Fax: (215) 355-7738. They have the handy hook-on kind that can easily be installed on an existing slate roof (in
copper, stainless steel, or hot-dipped galvanized). They also have a variety of other styles and types.
• Gough Snowguards — 4133 Du Bois Blvd., Brookfield, IL 60513; www.snoguard.com; all types of snowguards
• M. J. Mullane Company — 17 Mason Street (P. O. Box 108), Hudson, MA 01749; Ph: (508) 568-0597, Fax: (508) 568-
9227. The have a wide variety of snow guards, including bronze and aluminum cast.
• Vermont Slate and Copper Services — 55 C Gonyeau Road, Milton, VT 05468; Ph: (802) 893-7703, Fax: (802) 893-
1143. They have custom-made copper snow guards, leader boxes and finials.
• Zaleski — 11 Alsen Street, New Britain, CT 06053; Ph: (203) 225-1614, Fax: (203) 225-1060. Their slate snow guards pro-
trude between the slates and hook on the top of the slate without the need for nailing.

SOURCES OF LIGHTNING RODS, WEATHER VANES, FINIALS

• Automatic Lightning Protection — 11072 W. Mohawk Lane, Sun City, AZ 85373; Ph: 1-800-532-0990; Over 200 styles of
lightning rods and weather vanes.
• Colonial Works (weather vanes) — PO Box 46457, Hollywood, CA 90046; Ph: 213-460-6838.
• Crosswinds Weathervanes - 29 Buttonwood St., Bristol, RI 02809; Ph 401-253-0344
• Denninger Weather Vanes and Finials — 77 W. Whipple Road, Middletown, New York 10940-9801; Ph/fax: 914-343-
2229.
• Fischer Artworks — 6530 S. Windermere St., Littleton, CO 80120; Ph: 303-798-484 or 1/800-441-6067, Fax:795-8805;
Copper and cast bronze lightning rods with copper or glass globes.
• Independent Protection Company., Inc., - PO Box 537, Goshen, IN 46527; Ph: 219-533-4116, Fax: 219-534-3719. A vari-
ety of lightning rods, including old style (antique).
• Lehman’s Hardware — One Lehman Circle, Kidron, Ohio 44636; Ph: 330-857-5757, Fax: 330-857-5785; Email:
GetLehmans@aol.com; web site: http://www.lehmans.com; A variety of both lightning rods and weathervanes.
• Vanes and Things (dog motif weather vanes) - 1112 East C. Street, Commerce, OK 74339; Ph: 918-675-4262.
• Vermont Slate and Copper Services — 55 C Gonyeau Road, Milton, VT 05468; Ph: 802-893-7703, Fax: 802-893-1143.
Finials.

292 The Slate Roof Bible — Chapter 21 — Tile Roofs and Misc.
 REFERENCES
CHAPTER 6 — PENNSYLVANIA
CHAPTER 2 — WHAT IS SLATE?
• Behre, Charles E., (1933); Slate in Pennsylvania; Pennsylvania Geological
• Behre, Charles E., (1933), Slate in Pennsylvania, PA Geological Survey, Survey, Fourth Series, Bulletin M 16, pp. 19-21, 112, 173-187.
Fourth Series, Bulletin M 16. p. 29. • Bowles, Oliver, (1934); The Stone Industries; 1st ed., McGraw-Hill Book Co.,
• Bowles, (1934), The Stone Industries, First Edition, McGraw-Hill Book Co., Inc., New York and London, pp. 229-289.
Inc., New York and London, p. 230. • History of Trinity Evangelical Lutheran Church, 1878-1928; pp. 10-11.
• Levine, Jeffrey S., (1993), “The Repair, Replacement and Maintenance of • Pennsylvania State University, School of Mineral Industries; Properties and
Historic Slate Roofs,” U.S. Department of the Interior, National Park New Uses of Pennsylvania Slate; The Pennsylvania State College
Service, Preservation Briefs # 29. Bulletin, Volume XLI, No. 30, July 18, 1947, pp 7-25, 134-137.
• Moebs, Noel N., and Marshall, Thomas E., 1986, Geotechnology in Slate • (Author Unknown), Slate Roofs, (1926); available from Vermont Structural
Quarry Operations, Bureau of Mines. Slate Co., Fair Haven, Vermont 05743; phone: 802-265-4933/34 or 800-
• Pennsylvania State University, School of Mineral Industries, Properties and 343-1900, fax: 802-265-3865. A version is also available from Hilltop
New Uses of Pennsylvania Slate, The Pennsylvania State College Slate Co., PO Box 201, Middle Granville, NY 12849; phone: 518-642-
Bulletin, Volume XLI, No. 30, July 18, 1947, pp 7-25, 134-137. 2270/642-1453, fax: 518-642-1220.

CHAPTER 3 — IDENTIFYING ROOF SLATE CHAPTER 7 — PEACH BOTTOM

• Bowles, Oliver, and Coons, A. T., 1930, Slate in 1929, U. S. Department of • Behre, Charles E., (1933); Slate in Pennsylvania; Pennsylvania Geological
Commerce, Bureau of Mines, Mineral Resources of the United States, Survey, Fourth Series, Bulletin M 16; pp.359-390.
1929 - Part II (Pages 161-74). • Eisenberg, H. O., “The Story of Slate”; Slate Centennial; pp.13-16. (Date
unknown).
CHAPTER 4 — WALES • Faill, Roger T., and Sevon, W. D. (Eds.), (1994); “Guidebook for the 59th
Annual Field Conference of Pennsylvania Geologists,” specifically an
• Brigden, John, (date unknown), “Turning Stone into Bread,” (publisher article by Berkheiser, S.W., entitled “Some Commercial Aspects of the
unknown). This article was on file at the Buckingham-Virginia Slate Peach Bottom Slate: The Problem of Being Too Good”; pp 143-145.
Quarry in Arvonia, Virginia. • Norris, John C., (1898); History and Characteristics of the Peach Bottom
• Carrington, Douglas C., and Rushworth, T. F., (date unknown), “Slates to Roofing Slate; pp 4-16.
Velinheli - The Railways and Tramways of Dinorwic Slate Quarries
Llanberis,” found in Green Mountain College, Poultney, Vermont. CHAPTER 8 — VIRGINIA/GEORGIA
• “Chwareli a Chwarelwyr,” (Quarries and Quarrymen), 1974, Gwynedd
Archives Series, (A booklet to accompany an exhibition prepared to cel- • Bridgen, John; “Turning Stone into Bread,” article of unknown origin and
ebrate the centenary of the founding of the North Wales Quarrymen’s date, pp. 10-14.
Union), pp. 47-51. • Buckingham Slate Corporation BuyLine 0459; January, 1990, and other pub-
• Hartmann, George E., (1967), Americans from Wales, The Christopher lished information, Buckingham-Virginia Slate Corporation, One Main
Publishing House, Boston, MA, pp. 86-91. Street, Arvonia, VA 23004-0008 (1994).
• Holmes, Alan (1986), Slates from Abergynolwyn, (The Story of Bryneglwys • Chambers, S. Allen, Jr., (1989); “Of the Best Quality - Buckingham Slate,”
Slate Quarry), Gwynedd Archive Services, Caernarfon, Gwynedd, article in “Virginia Cavalcade,” Spring 1989, pp. 158-171.
Wales, pp 113-114. • Lindsay, Jean, (1974); A History of North Wales; David and Charles, Newton
• Isherwood, Graham (1982); Cwmorthin Slate Quarry; Revised edition pub- Abbot, London; p. 254.
lished by Adit Publications, Towerside, Pant-y-Buarth, Gwernaffield, • Redden, J. A., (1961), “Slate in Virginia,” article in “Mineral Industries
Mold, Clwyd, CH7 5ER, UK. Journal,” Vol. VIII, No. 3, September, 1961, published by the Virginia
• Isherwood, J. G., (1988); Slate From Blaenau Ffestiniog; AB Publishing, 33 Polytechnic Institute, Mineral Industries Departments, School of
Cannock St., Leicester LE4 7HR England. Engineering and Architecture, pp. 1-5.
• Lindsay, Jean, 1974, A History of the North Wales Slate Industry, David and • Terrell, Patricia, (1962); “Virginia Slate Industry: An Old Reliable Shows New
Charles, Newton Abbot, London, pp.11-27, 246-61, 286-295, 324-325. Vigor,” article in “The Commonwealth,” December 1962, p. 110.
• Encyclopedia Britannica, (1965), Volume 23, p. 296 (population of • Tucker, Beverley R. Jr., (date unknown); “Slate, Past Present and Future,”
Caernarvonshire and Merioneth in 1871). Buckingham-Virginia Slate Corporation, Richmond, Va.
• Lewis, M. J. T., and Denton, J. H., (1874), Rhosydd Slate Quarry, The • Galite Lightweight Structural Concrete, A Basic Manual; Georgia Lightweight
Cottage Press, Shrewsbury, England, P. 98. Aggregate Company, Atlanta, GA.
• McKinney, Margot, 1976, “The Welsh Heritage of the Slatebelt,” produced at • Geological Survey of Georgia, Bulletin 27, 1912.
Green Mountain College under a grant from HEW, Poultney, Vermont, • Knight, Lucian Lamar, (1917); Georgia and Georgians, Vol. II; Lewis
Journal Press, Inc. Publishing Co., Chicago and New York.
• Richards, Alan John (1994), Slate Quarrying at Corris; Gwasg Carreg • Memoirs of Georgia, Volume 1, (1895), The Southern Historical Association,
Gwalch, Llanrwst, Gwynedd, Wales. Atlanta, GA, p. 206.
• Richards, Alan John (1995); Slate Quarrying in Wales; Gwasg Carreg • Mintz, Leonora, “Slate Discovery Brought Mines to Van Wert” (newspaper
Gwalch, Iard yr Orsaf, Llanrwst, Gwynedd, Wales. article found in Rockmart, Georgia, Public Library; no date or source
• The Slate Industry of North Wales, Unit 4; A collection of historical docu- accompanied article). Other photocopied articles from the same library,
ments available at the Llechwedd Slate Quarry historical site at Blaenau kept in a manila file folder in a back room, also devoid of dates, page
Ffestiniog, North Wales. numbers or sources, were also used in the section on Georgia slate in
• Williams, Merfyn (1991); The Slate Industry, C. J. Thomas and Sons, this chapter.
(Haverfordwest) Ltd., Press Buildings, Merlins Bridge, Haverfordwest, • Sargent, Gordon D., and Jackson, Olin; “The Town that Stone Built”; North
Dyfed SA61 1XF, UK. Georgia Journal; Summer, 1996; pp. 28-35.
• Williams, M. C., and Lewis, M. J. T., 1989; Gwydir Slate Quarries, • Some Historical Facts About Rockmart’s First Industry - Slate; The Rockmart
Snowdonia National Park Centre, Plas Tan y Bwlch, Maentwrog, Journal, Thursday, July 20, 1967; p. 7-A.
Blaenau Ffestiniog, Gwynedd LL41 3YU, Wales.
CHAPTER 13 — INSTALLING
CHAPTER 5 — VERMONT/NEW YORK
• Hoppen, Ewald A., and Wagner, Dr. Wolfgang; Firschungen zur
• Beers, F. W., (1969); Atlas of Rutland County, Charles E. Tuttle Publishing Modernisierung des Schieferbergbaus, 1995.
Co., Rutland, VT, pp. 111-114. • Lorenz-Burmann-Schule Eslohe, Uberbetriebliche Unterweisung;
• Bowles, Oliver, (1934); The Stone Industries, 1st Ed., McGraw-Hill Book Co. Dachdeckungen.
Inc., New York and London, p. 278.
• Joslin, J., Fisbie, B. and Ruggles, F., (1875); A History of the Town of CHAPTER 15 — ROOF INSCRIPTIONS AND DESIGNS
Poultney, Vermont, From Its Settlement to the Year 1875, Poultney:
Journal Printing Office, pp. 181-187. • The Slate Roofer (1905), by Auld and Conger Co., Cleveland, Ohio.
• Morrow, John A., (1970); A Century of Hard Rock - The Story of Rising and
Nelson Slate Company, Grastorf Press, Granville, NY. CHAPTER 19 — FLASHING
• Ruggles Stone Machinery Catalog; Ruggles Machine Co., Poultney, VT
(Established 1828). This catalog provided the illustrations of the slate- • Copper Flashings and Weatherings - A Practical Handbook (1951);
working equipment in this chapter. Special thanks to Paul B. Boyce and Published by the Copper Development Association, Kendals Hall,
the East Poultney Historical Society. Radlett, Herts, England.
• Sharrow, Gregory (ed.), (1992); Many Cultures, One People; The Vermont • Slate Roofs (author unknown), (1926); available from Vermont Structural
Folk Life Center, Middlebury, VT 05753, pp. 232-235. Slate Co., Fair Haven, Vermont 05743; an abbreviated version is also
• Smith, H. P., and Rann, W. S. (ed.), (1886); History of Rutland County, available from Hilltop Slate Co., Middle Granville, NY 12849.
Vermont; D. Mason and Co., Syracuse, NY, pp. 192-198. • Architectural Sheet Metal Manual (Fifth edition, 1993); Sheet Metal and Air
Conditioning Contractors National Association, Inc, 4201 Lafayette

The Slate Roof Bible — References 293

 Center Drive, Chantilly, Virginia 22021. 1979 (Vol. XI, No. 3): pp 77-88. APT Bulletin.
• The NRCA Roofing and Waterproofing Manual (Third Edition - 1990); • Marshall, Philip C. "Slate Roofs: Conserving A New England Resource." Apr
National Roofing Contractors Association, O’Hare International Center, 1979 (Volume 4, Number 1): pp 1-2.
10255 W. Higgins Road, Suite 600, Rosemont, IL 60018-5607; Ph: 708- • McKee, Harley J. "Slate Roofing." 1970 (Vol. II, Nos. 1-2): pp 77-84. Bulletin
299-9070; Fax: 708-299-1183. of APT (The Association for Preservation Technology).
• Soldering Manual, second edition, revised (1978); American Welding Society, • Merrill, George P., New York: John Wiley & Sons, 1897: pp 345-365, 382-
Inc., 2501 N. W. 7th Street, Miami, FL 33125. 385. Stones for Building and Decoration.
• Merriman, M. "Perspectives — The Strength and Weathering Qualities of
CHAPTER 20 — VALLEYS Roofing Slate, A Reprint of an 1892 Article from the Transactions of the
American Society of Civil Engineers." Fall/Winter 1985 (No. 9): pp 12+.
• Jose Luis Menendez Seigas, (1995); Architecture and Techniques of Slate Technology and Conservation.
Roofing; Centro Technologico de la Pizarra de Galicia. • Merriman, Mansfield. "The Slate Regions of Pennsylvania." July 1898,
Volume XVII, Number 2 (Indianapolis, Indiana: Stone Magazine Review
CHAPTER 21 — TILE ROOFS AND MISC. Pub. Co, 1889): pp 77- 90.
• Morrison, Hugh. New York: Dover Publications, Inc., 1952: pp 36, 75, 170,
• Hobson, Vincent H., (2001), Historic and Obsolete Roofing Tiles; Remai 271, 514. Early American Architecture — From the First Colonial
Publishing Co., Inc., Evergreen Colorado, USA Settlements to the National Period.
• Morrow, John A. Granville, NY: Grastorf Press, 1970: pp 1-32. A Century of
ADDITIONAL BIBLIOGRAPHY Hard Rock — the story of Rising and Nelson Slate Company.
special thanks to Terry Hughes of the Stone Roof Association; • New York: Revere Copper Products, Inc., 1987 (7th ed.). Copper & Common
http://www.stoneroof.org.uk Sense, To obtain a copy of this publication, contact: Revere Copper
Products, Inc., Corporate Headquarters, One Revere Park, Rome, NY
• Ashurst, John, and Dimes, Francis G. London: Butterworth-Heinemann, 13440-5561 Tel: 800-448-1776. Fax 315.338.2224. Web: www.reverecop-
1990: pp 137-144. Conservation of Building and Decorative Stone - per.com.
Volume 1. • Perkins, George H. Montpelier, VT: Argus and Patrick Printing House, 1904:
• Bates, Robert L., New York: Dover Publications, Inc., 1969: pp 59-69., pp 47-51. Report of the State Geologist on the Mineral Industries and
Geology of the Industrial Rocks and Minerals. Geology of Certain Areas of Vermont, 1903-1904 — Fourth of Series.
• Behre, Charles H. Jr., Harrisburg, PA: Department of Forests and • Perkins, George H. Montpelier, VT: Argus and Patriot Press, 1906: pp 56-58,
Waters/Topographic and Geologic Survey, 1927: pp 1-308. Slate in 220-231, 260-261. Report of the State Geologist on the Mineral Industries
Northampton County Pennsylvania — Pennsylvania, Geological Survey, and Geology of Certain Areas of Vermont, 1905-1906 - Fifth of Series.
Fourth Series, Bulletin M9. • Perkins, George H. Report of the State Geologist on the Mineral Industries
• Behre, Charles H. Jr., Harrisburg, PA: Department of Internal and Geology of Vermont, 1911-1912 — Eighth of Series. Montpelier, VT:
Affairs/Topographic and Geologic Survey, 1933: pp 1-400. Slate in Capital City Press, 1912.
Pennsylvania — Pennsylvania Geological Survey, Fourth Series, Bulletin • Peterson, Charles E. (ed.). Mendham, NJ: The Astragal Press, 1976: pp 38-
M16. 39, 138-141, 384-387. Building Early America.
• Bowles, Oliver. New York: McGraw-Hill Book Company, Inc., 1934: pp 229- • Richards, Koziol, and Stockbridge, Jerry. "Detecting Water Leaks in Slate
289. The Stone Industries. and Tile Roofs." 1987 (Vol. 19, No. 2): pp 6-9. APT Bulletin.
• Bowles, Oliver. Washington, D.C.: United States Department of the Interior, • Rockhill, Dan. "Tudor Hardtop: Building A Slate Roofed Cottage on A Kansas
June 1955: pp 1-12. Slate — Bureau of Mines Information Circular 7719. Moor." 1988 June/July (V. 47): pp 56-60., Fine Homebuilding.
• Brumbaugh, James E., New York: Macmillan Publishing Company, 1986: pp • School of Mineral Industries and Experiment Station. The Pennsylvania State
410-432. Complete Roofing Handbook — Installation, Maintenance, College Bulletin, Volume XLI, July 18, 1947, No. 30: pp 1-168. Properties
Repair. and New Uses of PA Slate — Bulletin #47: Utilization of Waste Slate.
• Building Stone Board of Regents of the Smithsonian Institution (Annual • Stanier, Peter H. Aylesbury, Bucks, United Kingdom: Shire Publications Ltd,
Report 1886). Washington: Government Printing Office, 1889: pp 464- 1985: pp 23-28. Shire Album 134: Quarries and Quarrying.
471, 488, 509, 510, 549, 551, 556, 567, 572, 573, 591, 595, 603, 606, • Stone, Ralph W. Harrisburg, PA: Dept. of Internal Affairs/Topographic and
609, 616, 629. Report of the United States National Museum. Geologic Survey, 1932: pp 6, 14, 239, 299. Building Stones of PA —
• Clifton-Taylor, Alec. London: Faber and Faber Limited, 1972: pp 158-175. Pennsylvania Geological Survey, Fourth Series, Bulletin M15.
The Pattern of English Building. • Sweetser, Sarah M. "Roofing for Historic Buildings." Washington, D.C.: U.S.
• Dale, T. Nelson et al., Washington: Government Printing Office, 1914: pp 1- Department of the Interior, Technical Preservation Services Division,
220., Slate in the United States — Department of the Interior, United 1975: pp 1-8. Preservation Briefs, No 4.
States Geological Survey, Bulletin 586. • Vaux, Calvert. New York: Da Capo Press, 1968 (reprint of original 1857 pub-
• Day, David Talbot. Washington: Government Printing Office, 1892: pp 373- lication). Villas and Cottages.
440. Mineral Resources of the United States, 1889 and 1890 (United • "Wales Covers Ireland." 1987 Jan. (V.18, N. 1): pp 24-25. Plan: Architecture
States Geological Survey). and Interior Design in Ireland.
• Downing, Andrew Jackson. New York: Dover Publications, 1981 (reprint of • Warseck, K. "Historic Roofing." 1989 June (V. 70): pp 98-103. Progressive
1873 edition). Victorian Cottage Residences. Architecture.
• "Early Roofing Materials." 1970 (Vol. II, Nos. 1-2): pp 18-51. Bulletin of APT • Weaver, Kenneth N. (Director). Baltimore, Maryland: State of Maryland,
(The Association for Preservation Technology). 1969: pp 39-45, 104-106. The Geology of Harford County, Maryland —
• Earney, Fillmore C. The Journal of Geography, Volume LXII, No. 7, October, State of Maryland, Department of Natural Resources, MD Geol. Survey.
1963: pp 300-310. The Slate Industry of Vermont. • Williams, Mefyn. Buckinghamshire, United Kingdom: Shire Publications Ltd,
• Evergreen Slate Co. Inc., Granville, New York: Evergreen Slate Company., 1991: pp 1-32. Shire Album 268: The Slate Industry.
Slate Roofing — A Complete Guide to Roofing Slate and Application • Woodward, George E. and Thompson, Edward G. New York: Dover
Techniques. Publications, Inc., 1988 (reprint of original 1869 edition). A Victorian
• Garcia-Guinea, J. "Spanish Roofing Slate Deposits." 1997 Dec. (V. 106): pp Housebuilder's Guide — "Woodward's National Architect" of 1869.
B205. Transactions (Section B, Applied Earth Science).
• Gove, Les. "Slate Roof Repairs." 1990. Journal of Light Construction, Stone
World Magazine.
• Hance, Peter, and Hart, David McLauren. Laconia, NH: City, Planning
Department, 1978: pp 1-130., Slates, Shingles, and Shakes.
• Harrisburg: Board of Commissioners for the Second Geological Survey,
1883: pp 83-160. The Geology of Lehigh and Northampton Counties -
Second Geological Survey of PA: Report of Progress, D3, Vol. I.
• Hawkins, Judy, and MacDonald, Susan. "Roofs of England: Reviving A Lost
Industry." July 1997 (N. 32): p 10. English Heritage Conservation Bulletin.
• Hebert, Tony. Roofs of England. "On the Slate (Welsh Quarries)." Aug. 1989
(V. 5, No. 11): pp 16-20. Traditional Homes.
• Hunt, B. "The Changing Face of Slate — How to Assess Roofing Slate in the
Light of Some Recent Failures and A Proposed New European Standard."
1994 (V. 29, N. 4): pp 14. Stone Industries.
• Kimball, Fiske. New York: Dover Publications, Inc., 1966 (original publication
1922): pp 40-44. Domestic Architecture Of the American Colonies and of
the Early Republic.
• Levine, Jeffrey S. "Slate from the Source." 1997 Aug. (V. 25, N. 4): pp 36-39.
Old House Journal.
• "Living National Treasure." 16 May 1996 (Vol. 190, No. 2): pp 70-71. Country
Life; An article exploring the task of riving (i.e. splitting) quarried slate by
hand, featuring a profile of Rex Barrow in England's Lake District.
• Marshall, Philip C. "Polychromatic Roofing Slate of Vermont and New York."

294 The Slate Roof Bible — References and Bibliography

 Index
A brachiopods--89
brass--235, 236
Chestnut Level Cemetery--14
Chestnut Level Presbyterian
roof--283
cleats--267, 289, 290
ABC Supply Co., Inc.--133 Brazil--17, 103 Church--83 cleavage--15, 16, 17
aerial carrier--64 brick--249, 252, 253, 254, 258 chicken ladders--125, 136 cleavage plane--15, 16
aggregate--89, 92, 94, 95 Brigden, John--35 chimney flashing--218, 219, 223 coating slate roofs--217
air pollution--30 British Isles--177 chimney swifts--123 Cochran, Doug--306
air-dried lumber--143 British Standards Institution--41 chimneys--211, 216, 218, 223, 237, cold rolled--235
Albion Run--19 Buckingham--25, 27, 29, 30, 32, 57, 247, 249, 250, 251, 252, 253, collar ties--148
Alfred MacAlpine Ltd.--112 85, 86, 87, 89, 90, 91, 92 254, 255, 256, 257, 258, 259, Colonial Works--292
Algiers--90 built-in gutters--213, 229, 239, 247 260, 261, 262, 263, 264, 265, Colorado--52
Allen, Colonel Alonson--57 bumble bees--120 266 concrete filler--94
Altdeutsche--179, 189 butt and a fireside--61 best location for--250 condensation--147, 148
aluminum ladders--123, 124 Buttermere--112 building a chimney--250, 253 cone--175
aluminum planks--139, 142
aluminum ridge metal--224 C chimney fires--250
cricket--253, 266
surface area of--175
Conowingo Dam--84
Amish--209 Caernarvon--59, 90 flashing--257 contractors--84, 85, 145, 151, 159,
annealing--235 calcium--109 apron--253, 258 211, 212, 214, 216, 218, 225,
apron flashing--237, 253, 258 California--26, 29, 52 back flashing--258, 260 227, 268, 277, 280, 289, 293,
ardesia--109 Camara and Sons Slate Co.--69, corner leakage--257 294
Argentina--17, 29 302, 303 counter flashing--257, 258 Copper Development Association--
Arkansas--19, 26, 29, 57, 225, 229, Camara, Dave--302 folded corner flashing--258 235, 236
247 Camara, Shawn--69, 302 folded soldered seams--258 copper flashing--235
Little Rock--225, 229, 247 Cambrian--15, 19, 37, 95, 101, 108 single side-piece system--258 16-ounce copper--289
Arlington National Cemetery--101 Canada (see also Newfoundland)-- soldered gusset pieces--258 20-ounce copper--285, 287, 289
Arvon--90 14, 16, 17, 19, 28, 30, 38, 57, 97, step flashing--257, 258 expansion and contraction of--
Arvonia-Buckingham slate belt--89, 98, 99, 100, 101, 103 top flashing--258, 260 236
90 Melbourne--100, 101 wedges--266 lead-coated--235, 239
asbestos roofs--40, 255, 283, 286 Newfoundland--19, 57 German--249 mechanical properties of--235
diamond pattern--287 Burgoyne’s Cove--57 leaks--223 tensile strength--235
maintenance--286 North Country Slate--100, 300 leaning--250 using--236
patterns--287 Quebec--100, 101 maintenance and repair issues-- copper nails--140, 141, 224
removal of--286 Bedard Quarry--101 249 copper ridge--164, 167, 169, 176,
asphalt roofs--151, 159, 168, 234 Danville--100, 101 rebuilding--249, 250, 252, 253, 224
asphalt shingle coating--94 Glendyne Quarry--100, 101 254 Cornish--101
asphalt shingles--213, 218 Kingsbury--100, 101 rebuilding the top of--252, 253 costs--213, 225, 229
ASTM testing--21 Melbourne Quarry--101 building a fancy top--254 counter flashings--238, 258, 266
Astor, William B.--85 New Rockland--101 corbeled--254 craft slate--208
attics--148 New Rockland Quarry--101 mixing mortar--252, 253 creosote--249, 250
Australia--17, 101, 103 Richmond--100, 101 reflashing (see also crinoids--89
Austria--17 Slate Interpretation Center--101 chimney,flashing)--253, 266 Crosswinds Weathervanes--292
Automatic Lightning Protection--292 Steele Quarry--101 reflashing job — before and crushed slate products--92
Avila, Sergio--230 St-Marc du Lac Long--100, 101 after--260 Crystal Palace Exposition--84, 87
Avila, Victor Manuel--230 Walton Slate--101 removing an old chimney--254 Cubelos, Ms. Pilar--115, 185
B Rimouski--100, 101
slate quarrying Areas--100
roof cement and fiberglass--223 cupola--239
badrockmen--43 China--17, 28, 29, 103, 105-108 curved eaves--169
St. Lawrence River--101 Beijing--105, 108 Cwt-y-Bugail--192, 229
Bahamas--103 Canadian slate--54, 97
bald-faced hornets--120 best time to visit--108 Czech Republic--17, 103
cannibalizing a roof--286
Bali--17 cant strip--158, 159, 162, 165, 212,
Chinese New Year--108
Chinese roofing slates--105
D
Bandurski, Lyle--229, 230 213, 269, 277 Dally Slate Company--77, 78
Bangor--90 Fang Shan--108
cap flashing--258 Hebei--105 Davies, Dafyyd--42
barn--8, 125, 144, 145, 149, 151, cap slates--162, 214, 225 Davis, Mr. G. W.--95
156, 205, 216, 217, 226, 231 Hubei--105, 108
Caparosa--86 Zhu Shan--108 Day, Arthur--98, 99
base flashing--258 capillary attraction--219, 221, 239, dead blow hammer--289
basic repair job--213 Zhu Xi--108
242 Jiangxi--105, 106 dead load--153
bats--117, 118, 120, 122, 123 carbon--18, 19, 27 decorative styles--191
bedding plane--15, 16 Mandarin--108
carbon monoxide--254 Men Tou Gou--105 Delabole slate--113
Belden--131 carbonate--178 Delaware and Hudson Railroad--66
Belgium--17, 40, 103 Shaanxi--105, 108
Carl Kammerling (CK) Company-- black slate--108 Delaware River--71, 74
Belize--103 103 Delaware Water Gap--31
Berger Building Products--292, 305 Shanghai--108
Carnegie Library--85 Sichuan--105 Denninger Weather Vanes and
Berridge, Neil--181 carpenter bees--120 Finials--292
Beucker, Harold--83 State Owned Enterprises--105
carriage--66 Xian--108 designs--191, 192, 193, 194, 195,
bib--139, 140, 214, 216, 217, 219, castle--5, 103, 110 196, 197, 198, 199, 200, 201
220, 225 Yangtze--108
Cathedral Gray--27 Yellow River--108 diamond saw--72, 77
Bill Davis Roofing--304 Cathedral of St. Andrew--192, 195, diamond wire machines--101
billiards slates--58, 72, 108, 109 Yunnan--105
225, 229, 247 Chinese black slate--106 Dinorwic--101
Biltmore Estate--85 silicon caulk--141, 142 ditch--62
black powder--62, 67 Chinese slate quarry--107
Cayman Islands--103 chip board--143 Dittmar, Dr. Uwe--104
blackboards--57, 58, 72 CCA treated lumber--164 Docker, William--87
blacksmith--75 chips--63
cement board--204 chisel--110 dormers--233, 237, 238, 286
block cutter--60, 62, 63, 67, 75 ceramic chimney liners--249 replacing the step flashing--238
Blue Mountain--71 Chlorite--15
ceramic tile roofs (see also clay Civil War--91, 94 shed roofed--238
Bocker--129, 132, 133 tile)--283 slate on their sides--238
Boer War--40 clay tile roofs--283
Chapman--27, 29, 31 pan tiles--283 top flashing on a shed roof--238
Boulay, Sophie--108, 109 Chapman slate--73, 76, 77 Dorothea Quarry--101
Bowles, Oliver--15 proper repair work--286
Chapman Slate Company--76, 77 shingle tiles--283 double nailed--214
box gutters--247, 287 Chapman Standard Quarry--76 drip edge--159, 168, 211, 212, 213
replacing--287 technique for replacing tiles on a

The Slate Roof Bible — Second Edition 311

dripstones--254
drumhouse--44, 45
234, 235, 237, 238, 240, 246,
247
G extension ladder--134, 138
feet--135
Durable Slate Company, Inc.--208, aluminum--234, 235, 236, 237, gable vents--148 fly--134, 135, 136
310 238, 239 Galite--95 making plumb--135, 136, 139
dynamite--62, 67 anodic--235, 236 galvanic action--141, 235 putting it up--134
chart--236
E cathodic--235, 236
chimney flashings--247 galvanic scale--235
taking it down--135
Grove City College--171, 266
Easedale slate--114 copper (see also copper)--233, galvanized metal primer--224 Grove City, PA--169, 170, 171, 173,
Eastern Europeans--66, 67 234, 235, 236, 237, 238, 239, galvanized ridge iron--223, 224 266
Ecole Superieure Couverture--110 240, 242, 243, 244, 246, 247 Georgia--14, 19, 26, 29, 30, 40, 52, guardrail systems--127
economy installation--230 1/8 hard--235 57, 89, 90, 91, 92, 93, 94, 95, 96, Guntermann, Georg--104
economy method--226 16 ounce--235, 240 226, 230, 278 gutter hangers--211
electric lines--123, 124 20 ounce--235, 242, 243, 246 Atlanta--95, 226, 230 gutters--211, 213, 216, 229
electrolyte--235 Bartow--95
electroplated nails--140
cold rolled--235
dead soft--235 Bartow County--92 H
end slates--158, 162, 214, 216 half hard--235 Blanceville Slate Mines--94 hail damage--149
England--5, 14, 17, 29, 35, 36, 37, lead-coated copper--235, 239 Cohutta--92 half-hard copper--235, 246
58, 61, 68, 84, 87, 90, 91, 112, mechanical properties of--235 Dug Down Mountains--92 half slates--214, 216
113, 144, 167, 168, 170, 180, sheet--235 Fairmount--52, 92, 95, 96 hammers--132, 133, 134
181, 255 strip--235 slate--95 installation--132
Aberdeenshire--37 tempers--235 Fannin County--92 European brands--132
Argyll--37 three quarter hard--235 Gordon--92, 95 Gilbert and Becker--132
British slate quarries--112 electro-negative--235, 236 Murray--92, 95 Stortz hammer--132
Burlington--112 electro-positive--235, 236 Pine Log--92 restoration--132
Buttermere Green Slate folded corners flashing method-- Polk County--92, 94 CK--132, 133
Company--112 247 Rockmart--52, 92, 93, 94, 95 Estwing Latthammers--132
Cornwall--37, 112, 113 galvanic action--235, 236 roofing slate production--95 Freund--132, 133
Crediton--255 galvanized steel--234, 235, 236, Sandy Springs--230, 278 hand tools--129, 130, 134
Cumbria--112 242 Savannah--94 aviation snips--134
Delabole Quarry--112 lead--233, 234, 235, 236, 237, Silicoa--92 chalk line--134
Devon--37, 167, 255 238, 239, 240, 242, 244 Van Wert--93, 94 flat pry bar--134
Kirby-in-Furness--112 weight--234 German roofing school--103, 189, hand tongs--134
Kirkstone quarries--112 rule when making step flashings-- 193, 195, 203 nail punch--134, 139
Lake District--37, 112, 113 237 German slating techniques--179, tape measure--134
slate producing regions--112 skylight flashing--237 189 thin chisel--134
Welsh quarries--112 soldered--238 Germany--5, 14, 17, 19, 29, 40, 90, tin snips--132, 134
Westmorland Green Slate--112 stainless steel--234, 235, 236, 103, 104, 105, 179, 180, 189, utility knife--134
Worcester--167 242, 244, 247 190, 191, 195, 203, 233 utility pencil--134
English--97 300 series--234 Bad Fredeburg--103, 104, 189, hard slate--5, 17, 20
engraving--208 400 series--234 233 hard vein--72, 76, 77, 92
Eureka slate quarry--97 terne-coated (see also terne- Bundenbach--103 hardwoods--144-148
Europe--7, 15, 16, 17, 21, 85, 89, coated stainless)--234 Erzgebirge--103 Harmony Homestead--195, 205
92, 101, 103, 105, 114, 144, 148, gauges--234 German slate--233 (see also Macoskey)
156, 168, 177, 179, 267, 280, step flashings--237, 238 Lehesten--103 harness--124
283 simple rule--238 Magog slate--233 Hathaway barn--191
European roofs--147, 178 terne-233 Mayen--5, 103, 104, 189, 203 headlap--144, 149, 150, 151, 158,
European Slating Methods--177- top flashing--238, 242 Mosel River Valley--103 159, 162, 168, 178, 208, 212,
189 vent pipe flashing--237, 238 Rathscheck Company--190 (see 213, 226, 230
Euroslate--108, 109 replacing--238 Rathscheck) head-nailed--178
Evergreen Slate Co.--67, 132 flat seam roofs (see also soldered- roofing trades--179 Heath Residence--170
expanded shale aggregate--95 seam)--283, 287, 289, 290, 291 Saxony Ore Mountains--103 heavies--170, 177, 181
eyebrow dormers--172-173, 226 floor covering--204, 208 Schlema--103 Hematite--15
F flux--236, 242, 244 slate roofing expertise--103
slating style--103, 179
Hewes, Joseph--87
Hicks, Clark--67
face nails--9, 214, 218 corrosive--242
intermediate--242 Altdeutsche--103, 105 hidden leaks--216, 218, 219, 260
Faill, Roger--83 Schuppen--105 high voltage lines--123
fairing strip--280 non-corrosive--242
rosin--242, 244 traditional slate roofs--179 Hill, Jonathan--68
fascia--211, 213 Gibraltar--17 Hilltop Slate Co.--68, 195, 309
fascia hangers--211, 213 Follansbee Steel--233, 234
Ford’s Theater--32 Gilbert & Becker Co., Inc.--304 hip slates--214, 218, 221
faulty old repairs--218 Gilbert and Becker slate hammer-- hips--146, 162, 164, 166, 167, 169,
felt paper--7, 143, 148, 151, 158, fossils--89
frame scaffolding--127 132, 133 214, 218, 219, 221, 224, 225
168, 176, 177, 180, 181, 226, Glendyne Quarry--89 lead--167
230, 246 framing the roof--148
France--14, 15, 17, 29, 40, 103, Glenridge Hall--171, 173, 226, 230, mitered hips--164, 169, 225
30 lb.--143, 147, 151, 158, 165, 278 saddle hip--218
176 110, 112, 129, 132
Angers--110, 112, 129 Golden Gate Bridge--95 Historic Scotland--112, 114
55 pound--151 gouge--62, 64 holes in slate roofs--218
always underneath the slates-- Black City--110
Cointreau liqueur--110 Gough Snowguards--292 holing--147, 177, 181
151 graduated pattern--178 honey bees--120
chalk lines--151 Fresnais Mine--110
Loire--110 graduated slate roofs--25, 149, 168, Hong Kong--105, 107, 108
half-lap--151 170, 171, 226, 230 hook ladders--117, 118, 123, 124,
nail spacing--151 Maine--110
Maine-et-Loire--110 examples of--170 125, 126, 136, 137, 138, 139,
fiberglass--216, 223, 287, 289 Granville, NY--195, 200, 201 142, 252, 253, 257
fiberglass shingles--5, 8 Paris--110
Poligny--110 Great Britain--40 (see England) getting it onto a roof--137
finding leaks--216 Great Depression--91 versatility of--138
finials--239, 292 roofing school--110
Trelaze--110, 112 Great Fire of London--40 Hooker, Daniel--58
Finnish--97 green lumber--145, 146, 152, 213 Hooker, PA--206
Fischer Artworks--292 Franvisa Slate Co.--114, 115, 185
French slate quarries--110 Green Mountain College--61 hot-dipped nails--141
fish scale slating--179 Greenstone Slate Co.--68, 307 Howes, Gary--208
flashing a chimney--257 Freund Company--103
Freund slating hammer--132 ground bees--120 Hughes, Terry--178
flashing slates--214, 216 ground ladders--123, 124, 134, 136, Hussey, David--180
flashing, fundamentals of--257 Fulton Corporation--138
139, 142
flashings--211, 216, 220, 229, 233,

312 The Slate Roof Bible — Second Edition

I Italian roofs--22-23, 178, 182
Italians--66, 67
Ligo, Linda MacWilliams--209
Ligo, N. Lee--209
master level training--105
mastic--13, 141
ice damming--144, 159, 168 Italy--14, 17, 20, 23, 29, 40, 103, liquid asphalt emulsion and fiber- Mayen--191, 195 (see Germany)
ice-dam-prone areas--212 108-109, 178 glass membrane--287 McKinney, Margot--61
IEL International--105, 107 Arma di Taggia--109 liquidus--239 McMorrow, Eleanor Evans--59
IFD--180 Chiavari--109 Little Rock, Arkansas--192, 195 mediums--177, 181
Illinois--52 Euroslate--108 live load--153 Menai Straits--35
India--17, 29, 103 Genoa--109 local lumber--145, 146, 148, 213 Mercer, PA--206, 220
Indiana--52 Gulf of Tegullio--108, 109 London--40 metal drip edges--159
Indianapolis--10 Orero--108 London World’s Fair--91 metals, properties of--236
inscriptions--191, 192, 193, 194, slate region--108 Losada, Francisco Vime--115, 185 Mexico--103
195, 196, 197, 198, 199, 200, history of--109 lumber--143, 144, 145, 146, 148, mica slate--94
201 Val Fontanabuona--109 152, 158, 164, 168, 170 Middle Granville, NY--195
installation hammers--132, 133
installing Roof Slate--143 J #2 grade--146
air dried--145, 146, 152
Midland Engineering Co.--195, 229,
301
“French” method--149 James City--90 average weight of--152 Minnesota--26, 29
10 Quick-Reference Steps--158 Japan--17, 101, 103 bad boards--146 Missouri--173, 174
American styles--143 Jefferson, Thomas--90 board feet--146, 152 miter hip--164
building a 150-year roof--164 Jenkins, Orion--3, 109 grades--152 Monson--25, 26, 27, 29, 30, 37, 57
color scheme--171 jenkinsslate.com--14, 129, 132, green--146 Monson slate--89
Dutch lap--149 133, 138, 141, 299 kiln-dried--145, 146, 164 mortar--249, 250, 252, 253, 254,
economy method--151, 169 John Stortz and Son, Inc.--134, 309 local--146 257, 258, 260, 266
excessively large, heavy slates-- Johns Hopkins University--85 northern hardwoods--147 Mosel Schieffer (slate)--103
143 Jones, Colonel Seaborn--94 planed--146 Mt. Snowden--35
felt paper between rows--151 Jones, Robert--180 rough sawn--148 mud daubers--120
graduated--149, 168, 170, 171, Jones, Robert M.--75 softwoods--146 Mystery House--10, 11
173 Jones, William Griffith--97
in hurricane prone areas--143 jumpers--41, 62
southern yellow pine--147
species--146, 148, 152, 153
N
installing--149 jwmpars--41 characteristics of--152 nail and bib--214, 216
lath and peg roof construction--
144
K stickering--146, 152, 176 nail hole in slate--220
nail holes--63, 76, 78, 114, 143,
Kansas--52 Luxemburg--17
laying out a roof--159 147, 149, 152, 168, 170, 203,
Old German style--149 Katzenberg Mine--104 M 208
open slating--149 Kellow, Joseph--75 M. J. Mullane Company--292 countersinking--63, 76, 168
random width pattern--151 Kelly, James--60 Macoskey Center for Sustainable over-nailing--63
side-butts--171 Kennedy Memorial--99 Systems Research and under-nailing--63
sidelap--149, 159, 169 Ketler Estate--170, 173 Education--195 (see Harmony) nail length--147, 150
simple installation sequence--165 kiln dried boards--143 Magog Slate--103, 104, 233 nailhead--63
slopes--144 Kurtz, Steve--229 Maine--14, 18, 19, 25, 26, 27, 29, rubbing on the overlapping slate--
standard overlap pattern--149 L 30, 37, 40, 57, 72, 90, 97, 98, 99, 63
sufficient headlap--149, 159 ladder (see also ground ladder)-- 100, 101 nails--7, 9, 13, 129, 130, 132, 134,
traditional British style--143 135 Bangor--99 138, 139, 140, 141, 142, 143,
what not to do--168 hook ladders (see hook ladders)-- Blanchard--99 144, 145, 146, 147, 149, 150,
installing slate roofs--116, 149 136 Brownsville--99 151, 158, 162, 164, 167, 168,
insulation--148, 159 roof ladders--136 Burmah Quarry--99 169, 174
interior roof spaces--148 ladder brackets--124, 126, 142 Burnham--99 aluminum--140
International Federation for the ladder hook--124, 136, 138 Cove Quarry--97 calculating nail length--140
Roofing Trades--180 pointed ones--137 Dexter and Portland Co.--97 copper--140, 147, 150
international slate--103, 104, 105, with a swivel wheel--136 Dirigo Quarry--99 cut steel--140
106, 107, 108, 109, 110, 111, ladder jacks--124, 126, 139, 142, Eighteen Quarry--99 electro-galvanized--140, 151
112, 113, 114, 115 253 Farm Quarry--99 galvanized--7
international slating styles--177 Lafayette Slate Mining Corporation- Forest Quarry--99 hot-dipped galvanized--140, 141,
Internationale Foderation des -71 General Slate Co.--99 147, 164
Dachdeckerhandwerks--180 Lake District slate--113 Hebron Pond Quarry--97 number needed for 100 square
Iowa--52 Lake Forest, IL--162 Kineo Quarry--99 feet of roof--150
Ireland--14, 38, 40, 90, 103, 112, laminated wood--143, 145, 159, Lake Hebron--97 plastic cap (simplex)--151
193 168, 213 Matthews Quarry--99 stainless steel nails--140, 147,
Ashford Bridge--112 landfills--8, 9, 203 Monson--97, 98, 99, 101 150, 158, 164, 168
Clonkilty--112 landmark roof--191, 197 slate from--97 steel--7, 13
Co. Clare--112 laser guided saw--101 Monson Pond--97, 99 National Museum of Wales--38
Co. Cork--112 lath--143, 145, 170, 177, 178, 179, Monson-Maine Co. vein--97 National Trust for Historic
Co. Down--112 180, 181 Monson-Maine Quarry--99 Preservation--226
Co. Kerry--112 Lath roofs--143, 144, 148, 205 Moosehead Lake--97 Neanderthal syndrome--11, 227
Co. Tipperary--112 lead--90 Oakland Quarry--99 Neanderthals--13, 211
Co. Wicklow--112 lead hips--167 Portland-Monson Co. vein--97 Netherlands--17, 40
Co. Mayo--112 lead-bearing metals--234, 235 Portland-Monson Quarry--99 New Brunswick--97
Curraghbally--112 leaks at ridges--223 Underground Quarry--99 New England Slate--68, 132, 200,
Dublin--40, 193 Lehigh--20 West Monson Quarry--99 204, 304
Killaloe--112 Lehigh River--71 Wilkins Quarry--99 New Jersey--14, 71, 173
Kilrush--112 Lehigh Valley Peach Bottom--87 maintenance--211, 225 Lafayette--71
Newtownards--112 Lehigh-Northampton--7, 30, 37, 51, mallet--110 Sussex County--71
Portroe--112 71, 72, 74, 92, 220 Marczuk, Monsignior Scott--229 New York--14, 18, 19, 25, 26, 27,
Ross--112 Lehman’s Hardware--292 Markcrow, Craig--68 28, 29, 30, 32, 40, 52, 89, 201
Valentia Island--112 Leininger, Chris--205 Martin, Pilar Cubelos--115, 185 Granville--12, 52, 57, 58, 59, 60,
Waterford County--112 Lesser, Guido--206 Maryland--14, 19, 26, 27, 32, 40, 61, 63, 67, 68, 69, 195, 200,
Westport--112 lettering schematics--201 71, 77, 81, 83, 84, 87 201
Wexford--112 lightning rods--291, 292 Cardiff--84 Hebron--57
Wicklow--112 sources of--292 Cardiff Township--84 Slateville--57
Irish--66, 67, 97 lights--177, 181 Harford County--84 Washington County--51, 57
Isherwood, J. G.--47 Ligo Architects--310 Massachusetts--167 West Granville--52
Italian Alps--156 Ligo, Brett--209 mast--66 New York City--101

The Slate Roof Bible — Second Edition 313

New York red slate--28, 138, 250 East Bangor--72, 75 rake--162 framing members--148, 175
New Zealand--101 Fox Chapel--83 random slating pattern--226 lath construction--145
Newfoundland--14, 28, 29, 30, 38, Grove City--169, 170, 171, 173, random width slates--151, 168, 171, pitch--149
99, 100, 101 266 (see Grove City) 178 sag--146, 148, 156, 159, 164
Burgoyne’s Cove--38, 100, 101 Harrisville--255 Ranney, Caleb B.--57 slope--148, 149, 153, 156, 158,
ISO 9002 Certification--101 Lancaster--71 Rathscheck--103, 104, 190, 191 159, 164, 174, 176
Trinity Bay--100, 101 Lehigh--71, 72, 74 (see Germany) strength of--148
North American Bocker--129, 132, Lehigh-Northampton district--71, Reclaimed Roofs, Inc.--306 roof accessories--289
133 72, 74 recycled roof slates--176, 203, 204, roof brackets--124, 126, 127, 138
North Carolina--26, 29 main slate deposit--72 205-209 roof cement--13, 141, 142, 214,
North Country Black--68 Mercer--246 Red Devil--131 216, 217, 219, 223, 224, 225
North Wales--59, 87, 90, 91, 92 names of veins--75 red slate--57 (see New York red) underneath slates--141, 225
Gwynedd--87 Northampton--71, 72, 74, 76 Reimann & Georger--138 wet surface--142
North Wales Quarry Proprietor’s Northampton County--51 repairing and restoring slate roofs-- roof cement and fiberglass--216,
Association--47 Peach Bottom district--71 210 223
North Wales Quarrymen’s Union-- Pen Argyl--18, 19, 71, 72, 73, 74, repairing drip edges--213 roof deck--143, 144, 145, 146, 147,
47 75, 77, 78, 79 repairs and restoration--210 151, 162, 179, 211, 213
Northampton--20 Pennsylvania Run--72 basic--213 breathing--147
Norway--17, 29, 40, 103 Phoenix Run--72 cap slate--214 roof Inscriptions--191
Notre Dame Academy--85 Pittsburgh--52, 61, 83 contractors--214, 216, 217, 218, roof jacks--124, 126, 127, 138, 139,
Nova Scotia--97 production of roof slate--73 219, 226, 230 140, 141, 203, 205, 270, 272
O Sandy Lake--127
Slatedale--72
face-nailing--214, 218
finding hidden leaks--216, 218,
nailing--138
removing--139
oak--145, 146, 148, 152 Slateford--71, 74 220, 221 using without nailing through
Occupational Safety and Health Slatington--71, 72 holes in slate--217 slates--141
Administration--127 Susquehanna River--71 I still can’t find the leak--219 roof jacks and planks--158, 169,
Ohio--52, 61, 156, 208 United States Run--72 ridges made of slate--225 205, 253, 257
Columbus--208 Wilkes Barre-Scranton--52 slate hip--214 roof lath--144, 145
Old Bangor Quarry--75 Wind Gap--51, 74 slate hook--214 roof platform--142
Old German slating--179 York--71 slate ridge--214 roof scaffold--126, 253
Old Line Museum--84 York County--51, 84, 85 slates along a valley--216 roof scaffolds--138, 139
Ordovician--37, 89, 108 Pennsylvania black slate--229 small slates--216 roof slate (see also "slate")
OSHA--127 Pennsylvania State Capitol--85 starter slate--214 active production today--26
P Penrhyn--101 temporarily sealing leaking val- basic colors--25
PA ribbon slate--218 Perlino, Umberto--205, 273 leys--216 black--25, 26, 27, 28, 29, 30, 31,
Paleozoic--92 Perry, Roland--84 replacing slates--129 32
Pangaea--16, 18, 19, 35 personal fall arrest systems--127 replacing valleys (see also valleys, brown--26, 30
Papay, Pete--72 Pfister Roofing--307 replacing)--267, 277 color--28
paper wasps--120 Philadelphia--73, 86, 87 restoration--211, 212, 213, 214, green--25
parallelogram--105, 179 Philadelphia Exposition--91 215, 216, 217, 218, 219, 220, Identifying--25, 28, 30
particle board--143, 164, 176, 213 Philippines--103 221, 222, 223, 224, 225, 226, inactive production today--26
parts of the roof--211 pipe scaffolding--142 227, 229, 230, 231 location of deposits in US--29
Peach Bottom--25, 26, 27, 29, 30, pitman--110 funding to help pay for--226 NY red--26 (see New York red)
32, 37, 57, 71, 72, 73, 74, 173, Pittsburgh--52, 61, 83 restoration hammers--132, 133 producing regions--26
174 Pizarras Franvisa--115, 185 (see ribbing--89 purple--25, 26, 27, 28, 29, 30, 32
Peach Bottom of Lehigh Valley--87 Franvisa) ribbons--18, 19, 20, 27, 31, 71, 74, sea green--25, 26, 27, 28, 29, 30,
Peach Bottom quarries--72 Plain Grove, PA--197, 209 75, 73, 76, 77, 89 32
Peach Bottom slate--20, 71, 73, 74, plane iron--110 ridge--214, 218, 223, 224, 225, 227 stained--30
81, 82, 83, 84, 85, 86, 87, 89, 92, planed lumber--145 leaks at--225 standard size--63
138 planks--124, 126, 127, 138, 139, ridge hooks--124, 125, 126 where used in 1929--26
analyses of--82 142, 213 ridge iron--162, 214, 223, 224, 225 world’s largest producer--29
comparison of--86 plug and feathers--16, 62, 64 crimped ends--224 roof tile salvage services--286
compression test--87 plugging--62 installing--224 roof vents--148, 168
crushing strength--87 plumbing vent pipe flashings--240 nailed--224 roofing schools--178, 179
deposit--84 plywood--143, 146, 147, 148, 158, ridge metal--214, 223, 224, 227 roofing slide guards--127
first discovered--85 159, 164, 213 ridge vents--148, 164 ropes--119, 124, 125, 126, 136
imitations--87 delamination--147, 159 ridges--164, 166, 167, 168, 211, rough-sawn lumber--145, 164, 176,
Pearson cutter--131 failure--147 214, 223, 224, 225, 229 213
Pecto--131 pneumatic hammers--101 ceramic tile--164, 223 rounded valleys--226, 280
peg and lath--145 pneumatic splitter--99 comb--214, 223 extra headlap--280
pegged slates--177, 178 pneumatic trimmers--101 copper--164 hidden flashings--280
Penn Big Bed Slate Co., Inc.--72, Port Chester, NY--71 galvanized--223 roof slope, valley length, etc--
306 Porter, James M.--74 gauge--223 280
Pennsylvania--6, 13, 14, 16, 17, 18, Portugal--17, 40, 103 paint--224 valley board--279, 280
19, 20, 25, 26, 27, 28, 29, 30, 31, President John F. Kennedy’s grave- lead--164, 167 rubbing against the slate--147
32, 40, 51, 52, 57, 59, 71, 90, 91, -101 metal--164, 214, 223 rubblers--43
92, 94, 95, 109, 127, 144, 171, pump jacks--139 ornate--167 Ruby Fluid--242
173, 176, 204, 205, 209, 211, Q saddle--214, 218 Rutile--15
220, 225, 227, 229, 231, 246, quarry sap--75
slate--164, 223
vents--164
S
266 Quarryville--14 S1--17, 20, 21, 72, 101, 164, 168
Acme Run--72 Rising and Nelson Slate Co.--66,
quartz--15, 19, 89 69, 171, 307 S2--17, 20, 21, 72
Albion Run--72, 73, 75 Quebec--14, 68, 89 (see Canada) S3--17, 21
Bangor--71, 72, 73, 74, 75, 77 Robinson, Ruth Ann--83
Belfast--71, 72 R rockman--43, 47, 62 saddle hip--164
saddles--66
Butler--86 R.W. Stokes Company--230, 306 Rockmart slate--92, 93, 94, 95
first quarry--94 safety--119, 120, 121, 122, 123,
Chapman--18, 19, 71, 72, 73, 76, Raboin, Douglas--167, 304 124, 125, 126, 127
77 rafters--144, 145, 146, 148, 156, Rockmart Slate Corporation--95
Rogers, W. B.--91 attitude--119
Danielsville--72 175, 176 rooftop hazards--120
Delta--46, 51, 71, 73, 81, 83, 84, recommended rafter sizes--153 Romans--105, 109, 179
roof bats--122
86, 87 ragged butt--149, 162 bees--117, 118, 120, 121, 122,
Diamond Run--72 rain gutter--211, 218 cannibalized roof--30

314 The Slate Roof Bible — Second Edition

 123 silicosis--43, 47 hand-held--131 soldering--234, 236, 238, 239, 242,
birds--123 Silurian--15, 108 using--131 244
chimneys--120, 122, 123, 126 skin cancer--123 one-hand cutters--132 definition of--239
co-workers--120, 124 skylights--233, 237, 258 slate dust--43, 47 pre-tinning--234, 242
dew--123 slate--(see also "roof slate") 6, 15 slate exports from the U.S.--103 tinning--234, 242
electrical wires--120, 123, 124 absorption characteristics--20 slate gang--63 washing the flux off after--242
equipment--124 age of--18 slate granules--72 wetting--242, 244
frost--123 and continental drift--17 slate hammers--132, 133, 134, 179 soldering iron--242, 244
heat--117, 118, 123 average absorption--18, 20 slate hook--138, 140, 141, 178, soldering principles--239
lightning--118, 120, 123 bake stones--38 213, 214, 216, 218 soldering tools and accessories--
rain--118, 121, 122, 123, 124 Bangor--18 slate imports to the U.S.--103 244
wind--118, 120, 123, 125 beds--15, 16, 18, 19 slate knife--42, 46 solid sheathing--145, 147, 148, 178
safety belt--124 billiard tables--58, 72, 108, 109 Slate Mine Road--95 solidus--239
safety codes--119, 124 black--21 slate pencils--57 South Africa--17, 29, 103
safety net systems--127 Buckingham--18, 89 slate punch--63, 64 South Bend, Indiana--195
safety standards for the construc- Canadian--16, 97 slate quarrying--71, 74 Spain--14, 17, 29, 103, 110, 114-
tion industry--127 carbonate content--21 slate ripper--129, 132, 147, 151, 115, 156, 178, 179, 184, 185
Sage, Ken--229 center nailed--112 214 Badajoz--115
Saint Patrick’s Cathedral--101 clay--15 and tarred slates--130 Barcelona--115
salvaging roof slate--203 cleavage--36 using--130 Galicia--156
San Francisco--91 determining the quality of--20 slate roof restoration--97 Guipuzcoa--115
sandblast stencil--208 abrasive hardness--20 slate roofs La Coruna--115
Sandy Lake, PA--272 acid resistance--20 installing (see also installing)--143 Leon--114, 115
Sandy Springs, GA--171, 173 elasticity--20 walking on--136 Lugo--115
sarking--178 porosity--20 slate splitter--75 Orense--114, 115, 184
sawmills--213 strength--20 Slate Valley Museum--59, 60, 201 Segovia--115
sawyer--146 toughness--20 slate valleys--280 Zamora--115
scaffolds (see also roof scaffolds)-- doubles--38, 41 slater’s lath--144, 147, 156 (see Spanish slate--110, 114, 115, 179,
127, 138, 139 European--103, 114 lath) 185
frame--139 expected durability--20 slater’s stake--132, 133 (see stake) Spanish slating--178
ground--139 fading--19, 21, 27, 28 slates splitter--60, 63
pipe--139 formation--18, 19 holing--170 splitting shanty--63
scallop--16 fossils--19 Installing (see also installing) spouting--211, 212
schematic--191, 195, 197 freak--62 styles--149 aluminum--212, 216, 217, 219,
schist--110 grain--16, 17, 20 largest standard size--149 220, 223, 224
school slates--57, 58 Hard Vein--18 nailing cast iron--212
Scotland--14, 103, 112, 113, 114, hearths--58 center-nailing--148 copper spouting--212
145, 168, 178 hooking--109 double-nailed--147 galvanized--212
Ballachulish--113 identify the type of--25 head-nailing--148 half-round--212
Banff-Aberdeen Slate Belts--113 igneous--15 over-nailing--147 St. Asaph Cathedral--38
Easedale Islands--113 Installing--116 needed for 100 square feet of St. Louis, MO--173, 174
Edinburgh--103, 114 Italian--21, 108-109 roof--150 staggered butt--149, 162-163
Grampian Highlands--113 mantels--58 ragged butts--149, 162 stainless steel flashing--164
Highland Boundary Fault--113 marbleized--58 random widths--149, 171 stainless steel nails--141, 229
Macduff quarries--113 mica--15, 19 shapes--165, 191 stainless steel slate hooks--178
Scottish slates--112 mineral composition of--15 side-lapped--149 stake--105, 134, 179
slate roofing history--112 Monson--18, 97 staggered butts--149, 162-163 standard slates--214
Scottish--97 Peach Bottom--6, 14, 16, 18, 20, standard thickness--147, 149, standing seam--287
Scottish slate--168, 178 81 150, 159, 168, 170 stand-offs--142
Scottish Slate Roof--177 per foot of row stacked--76 thicknesses--170 Staples residence--127
Scottish slating--178 produced for European markets-- ventilated starter course--158, 159, 212-214
sculp--16, 62 114 weight--148 steam power--97
sea green--2, 19, 21, 57, 59, 61, purple--27 Slatescape--95 steel--233, 234, 235, 236, 242, 244,
66, 67 punching the nail holes--76 Slatington Peach Bottom--87 247
sealing a chimney at the flashing-- rating scale--20 Slippery Rock University--195, 205 step flashing--164, 237, 238, 258
223 red--27 (see New York red) Slippery Rock, PA--195 Stevenson United Methodist
self-adhesive underlayments--143, ribbons--16, 18, 19 slitter--110 Church--32
146, 147, 148, 151, 159 runs--16, 19 Smid, Chuck--68, 200, 204 stick--66
self-dumping boxes--62 S1--20 Smith, Barry--300 stone roofs--22-23
self-dumping carriage--66 S2--14, 20 Smithsonian Institution Building--27, stone slate--145
semi-weathering gray--61 S3--20 89, 91, 167 stool and traverse--42, 46
sewer vent pipes--237 should be stacked on edge--76 snow aprons--159 Stortz, John C. and Son--129, 132,
shapes of roof slates--165 Slatington--18 snow guards--289, 291, 292 133, 134, 309
Sharr, Diane--206 spindlewhorl--38 sources of--292 Stortz hammer--132, 133
Sharr, Mike--206 splitting--16, 21 snow railings--291 Stortz, John--133, 134
sheathing--143, 144, 145, 146, 147, standard sizes--76 snow weight--149, 153 strap hangers--211, 212
148, 151, 153, 158, 164, 173, tonne of--110 Snowden Quarry--74 striking tool--252, 254
175, 176, 211, 212, 213, 217, trimming of--76 soft slate--5, 7, 14, 27, 20, 72, 73, styles of laying slate--149
220, 223, 226, 229 type--20, 21 74 Susquehanna River--81, 82, 84, 87
solid wood--144 unfading--26, 27, 28, 31 soft vein--72, 76 Sweden--17
sheaves--64, 66 weathering--19, 21, 27, 28 soft-slate roofs--214, 218 Swedes--97
sheet lead--229 Welsh--16 solder--287, 289, 290 swept valleys--278
Sheldon Slate Products Co.--99 Wind Gap--18 50/50 solder--236 Switzerland--17, 103
shim--212, 213, 214, 277 word origin--36 solder joints--244 Sykola, Pam--211
shouldering--178
shuffling slates--203
world’s largest consumer of--110
world’s largest producer of--110
lap seam--244
lock seam--244
T
Shuppen--179 slate blocks--75, 77 soldered-seam metal roofs--287 Tall Chimneys--209
side-lapped slates--149 converting into shingles--75 liquid asphalt emulsion--287, 289 tar--8, 13, 134, 141, 216, 217, 218,
sidelaps--144, 168, 171 slate bread--38 maintenance--287 220
silicon--164, 214, 216, 217, 218, slate cutters--131, 132 pans--289, 290, 291 Taran Brothers Slate Co.--69, 308
224, 225 diamond blade cutter--131 repair--289 Taran, Steve--69

The Slate Roof Bible — Second Edition 315

Tatko--99 laying slate into--267 Services--292 44, 49, 54
Taylor, Samuel--74 length of sections--267 Vermont Structural Slate Co.--68, Company--43
TCSII--234, 242 open--267 201, 308 Countess--41
tegmen--109 repair--216 very heavies--177, 181 deep mines--41
temper--235 replacing--227, 267, 273, 276, Vime, Mr.--115, 185 Duchess--41
Tennessee--19, 26, 29, 57 277 Virginia--14, 19, 26, 27, 29, 30, 32, exports of--40
terne--233, 234, 235, 236, 239, felt paper under valley metal-- 40, 52, 81, 85, 86, 87, 89, 90, 91, Kings--41
242, 247 277 92, 93, 94, 95, 96 Lady--41
terne coated stainless steel--164, installing the new valley flash- Albemarle County--90 Marchioness--41
195, 229, 252, 266, 284, 289, ing--276 Arvonia--52, 86, 89, 90 Princess--41
291 numbering the slates--268 slate bed--89 quarries--40
Terne II--233, 242 two valleys that converge at the Bremo Bluff--89 accidents--43
thatch--38, 40 top--276 Capitol--90 living and working conditions-
The Twelfth Century Slate Roofing valley replacement sequence-- Culpeper Counties--90 -40
Company--304 275 Esmont--90 respiratory diseases--43
thin-set epoxy mortar--204 reslating the valley--277 Fauquier--90 types of--47
Thomas, David--68 rounded--267, 276, 278, 280 Fluvanna counties--89 unions--47, 49
Thuringia--103 slate overlapping--267 James River--89 Queens--41
tile adhesive--208 slated valleys--279, 280 Quantico slate belt--90 Viscountes--41
tile hanger--283, 284, 286 soft copper valley flashing--280 slate quarries--89, 90, 91, 95 walls--204, 208
tile roofs--300 solder joints on--267 Spotsylvania Counties--90 wall cladding--189, 190
timber sizes and spans--148 solution to leaking valleys--216 Stafford--90 Washington D.C.--89, 226
tin--233, 234, 236, 239, 242, 244 standard open valley--269 Warrenton--90 weather hazards on slate roofs--123
tin solder--234 swept--268, 275, 278 Vittorio Terzo Arata--108, 109 weather marks--208
tinner’s green--224, 233
tinner’s red--223, 233
symmetrical--270
taking the old valley out--268
W weather vanes--292
weather-clipping--178
toeboards--127 water stop--270 Wales--14, 15, 16, 17, 19, 20, 28, Wegener, Alfred--16
toe-holds--144, 176 Vanes and Things--292 29, 30, 35, 36, 37, 38, 39, 40, 41, weight of slate roof--153
tongs--134 vapor barrier--148 42, 43, 44, 45, 46, 47, 48, 49, 50, weight of slate roof per 100 square
tongue-in-groove roof decking--143, Venezuela--103 51, 52, 53, 54, 55, 59, 61, 63, 66, feet--153
146 vent pipe flashings--237, 238, 240 112, 113, 144, 145, 168, 170, weight of slate stone--153
tools--129, 130, 131, 132, 133, 134, ventilated ridge--164, 224 180, 181 Weikel, Allen--83
135, 136, 137, 138, 139, 140, ventilating slate--148 Abergynolwyn--38 Welsh--59, 66, 67, 83, 84, 85, 87,
141, 142 ventilation--147, 148 Aberllefenni--38 90, 91, 94, 101
chisel--60, 63, 64, 67 verge--178 Bangor--36, 37, 38, 51 Welsh black slate--192,229
hand hammer--62, 64 Vermont--5, 6, 7, 8, 12, 13, 14, 15, Barmouth--181 Welsh chimney--254
mallets--64 16, 18, 19, 21, 25, 26, 27, 29, 30, Bethesda--35, 37, 43, 49, 51, 112 Welsh emigration--52
slate hammer--65 31, 32, 37, 38, 40, 51, 52, 54, 57, Blaenau Ffestiniog--36, 37, 39, Welsh Slate Museum--42, 44, 49
slate ripper--65 58, 59, 60, 61, 62, 63, 64, 65, 66, 41, 47, 112 West Middlesex, PA--205
slater’s stake--65 67, 68, 69, 89, 91, 95, 101, 144, Bryneglwys Quarry--43 Westmorland Green Slate Company
towers--174 162, 163, 169, 171, 173, 175, Caernarvon--36, 38, 52 Limited--112
Townville--7 176, 191, 192, 195, 197, 198, Caernarvonshire--36, 37, 38, 52, White House--95
traditional building methods--148 199, 200, 201, 204, 209 61 Williams and Sons Slate and Tile--
traditional Spanish slate roof--185 Blissville--51 Cilgwyn Quarry--38 74, 195
trilobites--19, 89 Brandon--197, 199, 200 Conway--38 Williams Creek Development
trimmer--63, 65 Bristol--57 Corris--38 Company--10
Trinity Slate--99, 101 Castleton--198 Corwen--37 Williams, A.J.--74
triple covering--109, 178, 183 Charlotte--197, 198 Cwt-y-Bugail--112, 229 Williams, Owen L.--61
triple-covering--178 Fair Haven--6, 51, 57, 58, 59, 60, Denbigh--36 Williams, Stephen--69
tuberculosis--47 61, 68, 69 Dinas Mawddwy--37 Williamsburg--90
Turner, Wm. Drew--69 first slate roof--58 Dinorwic--36, 37, 40, 42, 44, 45, wind damage--216
Turrets--174 Lake St. Catherine--163 47, 48, 49, 54 Wind Gap, PA--195
Dorothea--36, 37, 40, 47
U map of--58
Monkton--197 Elidir Fawr Mountain--36
wind-force--149
wire saw--72, 74
U.S. Department of Labor--127 Newport--101 Ffestiniog--36, 37, 38, 39, 40, 41, Wisconsin--52
U.S. Quarried Slate--60, 69, 307 Owens Quarry--67 47, 112 wonderbar--203, 224, 225
UK--101, 103, 105, 110, 112, 114, Pawlet--51, 52 Gloddfa Ganol Slate Mine--112 wooden pegs--144, 145 (see pegs)
178, 179 Pittsford--68, 204 Glyn Ceiriog--38 wooden shingles--40
Ulisky, Brent--3, 127 Poultney--51, 52, 58, 59, 60, 61, Gwydir--37 World Slating and Tiling
underlayment--7, 147, 151, 159, 66, 68 Gwynedd--35, 37 Championships--193
168, 246 Poultney Welsh Male Chorus--52 Llanberis--35, 37, 38, 42, 54 Belgium team--193
UTAH--26, 29, 52, 57 purple slate--6, 7, 8, 13 Llangollen--37, 38 World War One--91
V Rutland County--51, 57, 58, 59, Llechwedd--36, 37, 41, 43
Lord Penrhyn--47, 49
World War Two--92
valley slates--214 61 World’s Columbian Exposition--91
Rutland Town--191 Merioneth--36, 52 Wright, John--105, 107
valleys--211, 216, 225, 226, 229, Merionethshire--36, 37
267, 268, 269, 270, 271, 272, Salem--58
Scotch Hill--57, 59 Montgomery--36 X
273, 274, 275, 276, 277, 278, Mt. Snowdon--35 Xue, John--105
279, 280, 281, 282 slate
and felt paper--267, 269, 273, analysis of--59 Nantile--37, 38, 112
North Wales--36
Y
277 colors--28, 59 Yankee gutter--213
Slate Valley--57, 59, 60, 66 Pembroke--36
cement and fiberglass repair--216 Pembrokeshire--37 yellow jackets--120
Z
center “V” crimp--270 peak of slate production--66
South Poultney--51 Penrhyn--35, 36, 37, 38, 40, 43,
cleated--267, 269, 276 47, 49, 51, 52, 53
closed--267, 269, 270, 272, 277 Truthville--66 Zaleski--292
unfading green--6, 7, 229 Penrhyn Quarries--35, 36 zax--131
copper--280 Presely--37
creased valley--267, 276 Warren Switch--67 Zelienople--3
Wells--58, 60, 61 slate production in--37, 40 Zimmerman Estate--31, 173
expansion and contraction--267, Snowdonia--35, 37
269, 276, 277 West Pawlet--52, 57 zinc--233, 234, 235, 236, 242, 244
Whiting--199, 201 Towyn--37 zinc chloride--242, 244
exposure--277 Vivian Slate Quarry--35
felt underlayment--273 Vermont “sea green” slates--5, 231 zinc flashing--173
Vermont Slate and Copper Welsh slate--37, 38, 40, 42, 43, ZTAlloy--233
installation--269

316 The Slate Roof Bible — Second Edition

 Slate Roofing Industry Resource Guide
New and Used Roofing Slates, Ceramic Tiles, Tools, Equipment, Fasteners, and Flashing Metal
This listing is for informational purposes only and does not constitute an endorsement. For the latest updated industry resource listings see www.slateroofcentral.com.

Companies marked with an asterisk (*) are featured in a special ad section following this listing.

SOURCES OF NEW SLATE 100029; Ph 8610-64440324; Fx 8610-64426709; M/S SANKAR ANAND EXPORTS, 24-2-709,
AUSTRALIA sales@ghystone.com; www.ghystone.com Rajagopalapuram, Dargamitta, NELLORE - 524
MINTARO SLATE QUARRIES PTY LTD, PO Box 8, HEBEI IMPORT & EXPORT CORPORATION, No. 486 003 A.P., India; Ph +91 861 320518, 301934; Fx
Mintaro, South Australia 5415; Telephone: 61 8 West Heping Road, Shijiazhuang, P.R. China; Ph +91 861 322836; sanexpo@vsnl.com; www.slate-
8843 9077; Fax: 61 8 8843 9019; Location: 86-311-7813720 ext. 6407; Fx 86-311-7050674; granite.com
Quarries and Administration at Mintaro, near www.stone.hebei.net.cn NEERA J. NAYAR, Ph91-1899-224682,226123; Fx
Clare, South Australia IEL INTERNATIONAL LIMITED, 1301 Winsome 91-1899-222567;
SPALDING SLATE & STONE, Hill River Rd, House, 73, Wyndham Street, Central, Hong RAMESH REDDY, jagadeeswara_slates@yahoo.co.in
Spalding; (08) 8845 2191; Clare Quarry, Kong; Ph 852- 2522-2405; Fx 852-2522-2834; WORLDLINK EXIM OPERATIONS & SERVICES,
Broughton Valley Rd, Spalding; (08) 8843 4250 info@iel.com.hk; www.iel.com.hk/slate 17/17, Inbarajapuram 1st Street, off Bajanai Koil
BRAZIL LIU SHAOYU, Fx 0086-29-6243506 6280322; Road, Choolaimedu, Chennai - 600 094, Tamil
AARÃO & COHEN CORP., Rua Turim, 146 - shaoyu@public.xa.sn.cn Nadu India; Ph+91-44-23614315; rch_gun-
Congonhas - MG BRAZIL; Ph 36.415-000; SHAANXI LEESTONE CO., LTD., Ph (86)029- jans@sancharnet.com
aaraoecohen@ieg.com.br 7661183 7661189; Fx (86)029-7661184; slate- IRELAND
B2B INTERNACIONAL COMMERCIO E quarry@globalsources.com, CAPCO ROOFING CENTER, Unit 47/48 Broomhill
EMPREENDIMENTOS LTDA., R. Frei Gaspar, 931 www.naturalslate.com.cn/test Close, Tallaght, Dublin 24 Ireland; Ph 01 462
sala 11, Centro Sao Vicente-SP, BRAZIL, CEP SHAANXI WEIYIDA TRADE & DEVELOPMENT CO. 0740; Fx 01 462 0741; or: Mount Tallant Avenue,
11310-080; Ph 0055 13 3468 1212; Fx 0055 13 LTD., No.96 Xiying Road Xi¡¯an Shaanxi P.R. Terenure, Dublin 6W Ireland; Ph 01 490 2755;
3468 1011; export@b2binternacional.com.br; China 710054; Fx 86- 29 - 5514155/5543799; Ph Fx 01 490 1021; info@capco.ie; www.capco.ie
info@b2binternacional.com.br 86- 29- 5522582/5513336; darsim@163.com TEGRAL BUILDING PRODUCTS LTD., 6 South
BRTRADE (Ian Orellana) – Ph 55-31-99857756; Fx SHANGHAI LEIHUA SLATE CO., LTD., www.lei- Leinster St., Dublin 2 Ireland; Ph 01 676 3974;
55-31-33780037; brtrade@yahoo.com huaint.com; contact information: Tel:+86-21- Fx 01 676 2820; support@tegral.com;
MUNDIAL STONES, Rodovia MG 060 - Km 151 - 6406-5640, Fax:+86-21-6406-0292, Mobile: +86- www.tegral.com
Papagaio - MG - BRAZIL; Ph 55-37-32741117; 133-7915-0688, Email: info@leihuaint.com ITALY
Fx 55-37-32741999; SHENZHEN SEG GENERAL TRADING CO., LTD., EUROSLATE, 16040 Monteleone Di Cicagna, Orero
exporting.slate@nwm.com.br 6/F West, Huafa Building, Huafa Rd. N. Italy; Ph 39-0185-334-042; Fx 39-0185-334-233;
OPEN MART COMERCIAL EXPORTADORA, Ph 00 55 Shenzhen, China 518031; Ph: 86-755-326-3531; www.euroslate.it
31 3292-4692; www.openmart.com.br Fx: 86-755-323-4127 NORWAY
STONE TRADE, Papagaio – Minas Gerais – WEICHANG NATURAL STONE (SLATE) CO., LTD.; MINERA NORGE, AS, P.O. Box 68, 9501 Alta
BRAZIL; Ph/Fx 55 37 3274 0044; www.stone- Hong Kong; Ph 0086-29-88193888, 8569906, Norway; Ph 0047 784 35 333; Fx 0047 784 35
trade.com.br 8562316; Fx 0086-29-88193889; Mobile 0086 374; (Danmark-Finland-Iceland-Norway-
CANADA 1389 2888958, 1389-2888028 Sweden); info@naturstein.no
(Many American suppliers also carry Canadian slates.) info@westones.com; www.westones.com SPAIN
GLENDYNE QUARRY, 396 rue Principale, St. Marc YUN TAN SLATE FACTORY OF JIANGXI, Ph0086- (Many American suppliers also carry Spanish slates.)
du Lac Long Quebec G9L 1T0 CANADA; Ph 792-2596051; Fx 0086-792-2596051 CUPA PIZARRAS, Spanish HQ, La Medua, s/n,
418-893-7221; Fx 418-893-7346; Z. Z. INTERNATIONAL, INC., Ph 360-459-4093; Fx 32330, Sobradelo de Valdeorras (Orense), Ph: 00
NORTH COUNTRY SLATE, 8800 Sheppard Ave. 775-402-7608; ding@zzinternational.com; zzin- 34 988 335 580; Fax: 00 34 988 335 599; comer-
East, Toronto, Ontario CANADA M1B5R4; Ph ternational.com cial@cupire.com
416-724-4666 or 800-975-2835; Fx 416-281-8842; FRANCE GESTIO D'ENDERROS INMOBLES S.L., C/ Galicia,
info@ncslate.com; www.northcountryslate.com ASPIGAL, ZI Les Jonceaux B.P. 131, Hendaye 112 08223 Terrassa (Barcelona - SPAIN); Ph 34
NORTHERN ROOF TILES, 50 Dundas St. E., Cedex France 64701; Ph (33)-55-920-1757; Fx 937316515; Fx 34 937312455;
Dundas, ON CANANDA L9H 7K6 Ph 905-689- (33)-55-920-3916; aspigal@wanadoo.fr; gdenderrocs@cecot.es
4035, 888-678-6866; Fx 905-689-7099; www.aspigal.com PIZARRAS CASTRELOS, S.A.; Casaio s/n, 32337
sales@nothernrooftiles.com; www.northern- LARIVIERE, 36 bis rue Delaage, B.P. 446-49004 Caballeda de Valdeorras (Orense), Spain; Ph
rooftiles.com Angers Cedex 01, France; Ph 02 41 66 67 81; Fx 0034-988-324-760; Fx 0034-988-337-787; infocas-
ROOF TILE MANAGEMENT, INC., 2535 Drew Rd., 02 41 47 19 16; bmonnier@lariviere-sa.fr; trelos@castrelos.com; www.castrelos.com
Mississauga Ontario CANADA L4T 1G1; Ph www.lariviere-sa.fr PIZARRAS FRANVISA, c/o General Vives, 54,
905-672-9992; Fx 905-672-9902; www.rooftilem- GERMANY Ponferrada Leon, Spain; Ph 34-987-418-904; Fx
anagement.com JOHANN & BACKES, Flurstr. 11, 55626 34-987-414-158; UK and USA office, 8 Avenue
UNIVERSAL SLATE INTL., INC., 3821 9th St. SE, Bundenbach, Germany; Ph 0049-6544-9988-0; Mansions, St. Paul's Ave., London NW2 5UG
Calgary ALB CANADA T2G 3C7; Ph 403-287- Fx 0049-6544-99-8850; info@johann-backes.de; UK; Ph 44-181-459-3857; Fx 44-181-830-4047;
7763 or 888-67-SLATE; Fx 403-287-7736; zim- www.naturschiefer.de cubelos@mcmail.com
mer@universalslate.com; RATHSCHECK SCHIEFER, Postfach 17 52, Mayen- PIZARRAS SAMACA, S.A., E-32337 El Trigal
www.universalslate.com Katzenberg Germany D-56727; Ph Sobradelo de Valdeorras Orense, Spain; Ph 34-9-
CHINA (49)026519550; Fx (49)02651955100; info@rath- 883-24-770; Fx 34-9-883-24-733
(Many American suppliers also carry Chinese slates.) scheck.de; www.rathscheck.com PIZARRAS VILLAR DEL REY, S.L., 06192 Villar Del
BEIJING ORIENT SLATE & STONE CO., Ph (86)10- SCHIEFERGRUBEN MAGOG GMBH & CO. KG, Rey Badajoz, Spain; Ph 34-24-414-111 or 34-24-
6428-1976; root@orientslate.com; www.orients- Alter Bahnhof 9, D-57392 Bad Fredeburg; Ph 414-211; Fx 34-24-414-221
late.com 0049-2974-9620-0; Fx 0049-2974-9620-20; UK
BAODING VITIAN TRADING CO., LTD., Ph 0086- info@magog.de; www.magog.de (Some American suppliers also carry UK slates.)
312-2275655; Fx 0086-312-3023123; bao- INDIA ALFRED MCALPINE SLATE LTD., Bethesda Bangor
jiangyu@yahoo.com.cn HARSHINI EXPORTS, harshiniexports@yahoo.com Gwynedd WALES; Ph 44 (0) 1248-600656; Fx
CENTRAL & WEST CHINA SLATE CO., Wuhan HIMACHAL SLATE & STONE, Upper Julakari, 44 (0) 1248-601171; www.amslate.com
China 430077; Ph 86-27-8678-8771; Fx 86-8678- Chamba, Himachal Pradesh 176310 India; BURLINGTON SLATE LTD., Cavendish House
8771 Phone: 91-18-9922 4682; Cell: 91-18-1602 4682; Kirkby-in-Furness, Cumbria, WALES LA17
CHINA BSS NATURAL SLATE; Ph 8610-64968538; Fax: 91-18-9922 2567; neerajnayar@hotmail.com 7UN; Ph (44)01229-889-661; Fx (44)01229-889-
Fx 8610-64974573; slate@starstone.sina.net; U.S. Address and Contact: Dhiraj Nayar, 37 466; sales@burlingtonstone.co.uk; www.burling-
contact Ms Yan Exeter Rd, Short Hills, NJ 07078; Ph: 646 287 tonstone.co.uk/roofing.htm
GHY STONE CO., LTD., NO.3, Shenggu North 0047; 973 467 0169; Fax: 973 467 4743; CUPA NATURAL SLATE, UK & Ireland office; 45
Road Dongcheng District, Beijing, China dhiraj_nayar@yahoo.com Moray Place, Edinburgh EH3 6BQ; Ph: 00 44

The Slate Roof Bible — Second Edition 295

 SOURCES OF NEW SLATE (CONTINUED) *TILE ROOFS, INC., 9505 Corsair Rd., Frankfort, 972-612-0847
IL 60423; Ph 708-479-4366 or 888-708-TILE; Fx ROOF TILE AND SLATE COMPANY, THE, 1209
131 22 53 111; Fax: 00 44 131 22 05 463;
708-479-7865; tileroofs@aol.com; Carroll St., Carrollton, TX 75006; Ph 972-446-
uk@cupirepadesa.com; www.cupa.es
www.tileroofs.com 0005 or 800-446-0220; Fx 972-242-1923; rtsc-
CWT Y BUGAIL SLATE QUARRIES CO., LTD.,
MARYLAND dow@aol.com; www.claytile.com
Blaenau Ffestiniog Gwynedd LL413RG
ROOF CENTER, THE, 9055 Comprint Ct., Ste. 300, TILESEARCH, INC., 216 James St., Roanoke, TX
WALES; Ph 44-076-683-0204; Fx 44-076-683-
Gaithersburg, MD 20877; Ph 301-548-0548 or 76262; Ph 817-491-2444; Fx 817-491-2457;
1105
800-503-5500; Fx 301-548-0828; roof@roofcen- ts@tilesearch.net; www.tilesearch.net
HONISTER SLATE MINE, Honister Pass,
ter.com; www.roofcenter.com VERMONT
Borrowdale, Cumbria CA12 5XN, ENGLAND;
MASSACHUSSETS *CAMARA SLATE PRODUCTS, INC., P.O. Box 8, 963
Ph 017687 77230; info@honister-slate-
*MAHAN SLATE ROOFING COMPANY, PO Box S. Main St., Fair Haven, VT 05743; Ph 802-265-
mine.co.uk
2860, Springfield, MA 01101; Ph: 413-788-9529; 3200; Fx 802-265-2211; info@camaraslate.com,
SLATE AND STONE CONSULTANTS, Terry Hughes,
Fax: 413-467-2177, Email www.camaraslate.com
Ceunant, Caernarfon, Gwynedd LL55 4SA, UK;
MICHIGAN *GREENSTONE SLATE, 325 Upper Rd., PO Box
Ph 44 (0) 1286 650402; terry@ slateroof.co.uk;
OLD WORLD DISTRIBUTORS, 1601 West KL Ave. 134, Poultney, VT 05764; Ph 802-287-4333; Fx
www.stoneroof.org
Ste. 2, Kalamazoo, MI 49009; Ph 269-372-3916; 802-287-5720; info@greenstoneslate.com;
SLATE WORLD, 158 Wandsworth Bridge Road,
Fx 269-372-9852; owdist@net-link.net; www.greenstoneslate.com
Fulham UK SW6 5UL; Ph (44)020-7384-9595;
www.oldworlddistributors.com JUST SLATE, 208 Frog Hollow Rd., Brandon, VT
Fx (44)020-7384-9599; sales@slateworld.com
NEW YORK 05733; Ph/Fx 802-247-8145; justslate1@aol.com
www.slateworld.com
*EVERGREEN SLATE CO., INC., 68 E. Potter Ave., *NEW ENGLAND SLATE CO., 1385 US Rt 7,
WELSH SLATE LTD., Unit 205, 52 Upper St.,
Granville, NY 12832; Ph 518-642-2530; Fx 518- Pittsford, VT 05763; Ph 802-247-8809 or 1-888-
London N1 0QH UK; Ph 44(20)7354-0306; Fx
642-9313; slate@evergreenslate.com; www.ever- NE-SLATE; Fx 802-247-0089;
44(20)7354-8485; nblager@welshslate.com;
greenslate.com slate@neslate.com; www.neslate.com
www.welshslate.com
HILLTOP SLATE, INC., PO Box 201, Rt. 22A, TACONIC STONE LLC, 5 Brooklyn Heights, Fair
Middle Granville, NY 12849; Ph 518-642-2270; Haven, VT 05743; Ph 802-265-8163; taconic-
UNITED STATES
Fx 518-642-1220; hilltopslate@aol.com; stone@aol.com
ALABAMA
www.hilltopslate.com TARAN BROTHERS SLATE COMPANY, 2522
EMACK SLATE COMPANY, INC., 9 Office Park
NORTHEAST SLATE, 911 Central Ave., #152, Vermont Route 30 N, North Poultney, VT 05764;
Circle, Suite 120, Birmingham, AL 35223; Ph
Albany, NY 12206; Contact: Daniel Boone, ph: 802-265-3220
205-879-3424; Fx 205-879-5420; jim@emack-
518-339-1818; cell: 518-265-2766; fax: 518-391- VERMONT SPECIALTY SLATE, INC., PO Box 4,
slate.com; www.emackslate.com
2831; sales@northeastslate.com; Brandon, VT. 05733; store 855 North Street,
CALIFORNIA
http://www.northeastslate.com Forestdale, VT 05745; Ph 1-866-US-SLATE; Fx
*AMERICAN SLATE CO., 1900 Olympic Blvd. Ste.
*RISING AND NELSON SLATE CO., P.O. Box 336, 1-802-247-4209; info@vtslate.com;
200, Walnut Creek, CA 94596; Ph 925-977-4880
2027 County Rte. 23, Middle Granville, NY www.vtslate.com
or 800-553-5611; Fx 925-977-4885;
12849; Ph 518-642-3333; Fx 518-642-1819; sla- *VERMONT STRUCTURAL SLATE CO., INC., Box 98,
slatexpert@americanslate.com; www.americans-
terisingandnelson@adelphia.net 3 Prospect St., Fair Haven, VT 05743; Ph 802-
late.com
*SHELDON SLATE PRODUCTS, PO Box 199, Fox 265-4933 or 800-343-1900; Fx 802-265-3865;
ECHEGUREN SLATE, INC., 1495 Illinois St., San
Road, Middle Granville, NY 12849; Ph: 518-642- info@vermontstructuralslate.com; www.ver-
Francisco CA 94107; Ph 415-206-9343; Fx 415-
1280; Fax: 518-642-9085 montstructuralslate.com
206-9353; slate@echeguren.com; www.eche-
TATKO STONE PRODUCTS, 50 Columbus Street, VIRGINIA
guren.com
Granville, NY 12832; Contact: Robert Tatko, Ph: BUCKINGHAM-VIRGINIA SLATE CORP., 1 Main
COLORADO
518-642-1702; Fax: 518-642-3255; Cell: 518-642- Street, PO Box 8, Arvonia, VA 23004; Ph 434-
SOURCE PRODUCTS GROUP INC., 16000 Huron St.,
1733; http://www.tatkostone.com; 581-1131 or 800-235-8921; Fx 434-581-1130; bvs-
Broomfield, CO 80020; Ph 303-280-9595; Fx
tatkostone@joimail.com late@ceva.net; www.bvslate.com
303-280-2600; www.petraslate.com; www.tileroof-
NORTH CAROLINA *VIRGINIA SLATE, 100 East Main St., Richmond
ing.com
JOHN KING, 133 Hayfield Ct., Wilmington, NC VA 23219; Ph: 804-282-7929 or 888-VA-SLATE;
DELAWARE
28411; Ph 910-686-9394; Fx 910-686-3812; Fax: 804-285-4442; sales@virginiaslate.com;
SLATE INTERNATIONAL, INC., 3422 Old Capitol
jkingco1@earthlink.net www.virginiaslate.com
Trail, Ste. 1061, Wilmington, DE 19808; Ph 301-
THE TILE MAN, INC., 520 Vaiden Rd., Louisberg WISCONSIN
952-0120; Fx 301-952-0295;
NC 27549; Ph: 919-853-6923 or 888-263-0077; ENCHANTED IMPORTS, INC., PO Box 266, Land O'
ardelis@comcast.net;
Fax: (919) 853-6634; info@thetileman.com; Lakes, WI 54540; Ph 715-547-8000; Fx 715-547-
www.slateinternational.com
www.thetileman.com 8001, globalgatherings@aol.com; www.enchant-
FLORIDA
OHIO edforestimports.com
PREMIER ROOFING SPECIALISTS, INC., PO Box
DURABLE SLATE CO., 1050 N. Fourth St.,
2298, Lake City, FL 32056; Ph: 888-492-4789; SALVAGED ROOFING SLATE
Columbus, OH 43201; Ph 614-299-5522 or 800-
Fax: 386-719-9905; ricardo@premierroofs.com *ALLUVIUM CONSTRUCTION, 200 Lake Shore Dr.,
666-7445; Fx 614-299-7100;
TEJAS BORJA USA; 401 Redland Rd., Homestead, Marlton, NJ 08053; Ph 856-767-2700; Fx 856-
tile@durableslate.com; www.durableslate.com
FL 33030; Ph 305-594-4224 or 800-830-TILE; 768-7766; alluviumconstruction@comcast.net;
PENNSYLVANIA
Fx 305-242-6595; adam@tejasborja-usa.com; www.historicroofs.com;
DALLY SLATE CO., 500 Railroad Ave., Pen Argyl, www.thesteeplepeople.com.
www.tejasborja-usa.com
PA 18072; Ph 610-863-4172; Fx: 610-863-8388; *BLACK DIAMOND SLATE LLC., P.O. 30957,
GEORGIA
www.dallyslate.com Savannah, GA 31410; Ph 877-229-9277; Fx 912-
*BLACK DIAMOND SLATE LLC., P.O. 30957,
*JOSEPH JENKINS, INC., 143 Forest Lane, Grove 898-2339; ken@blackdiamondslate.c- om;
Savannah, GA 31410; Ph 877-229-9277; Fx 912-
City, PA 16127; Ph 814-786-9085 or 866-641- www.blackdiamondslate.com
898-2339; ken@blackdiamondslate.com;
7141; Fx 814-786-8209; mail@joseph- CUSTOM TILE ROOFING, INC., 2875 West
www.blackdiamondslate.com
jenkins.com; www.slateroofcentral.com Hampden Ave., Englewood, CO 80110; Ph 303-
CLASSIC SLATE AND TILE, 80 W. Wieuca Rd.,
*PENN BIG BED, PO Box 184, 8450 Brown St., 761-3831; Fx 303-761-3839; ctrvince@qwest.net;
Suite 204, Box 25, Atlanta, GA 30342; Ph: 404-
Slatington, PA 18080; Ph 610-767-4601; Fx 610- www.customtileroofing.com
847-0188; Fax: 404-847-0166; clastile@bell-
767-9252; pbbslate@ptd.net; www.pennbigbeds- DURABLE SLATE CO., 1050 N. Fourth St.,
south.net; Contact: Steve Yoder
late.com Columbus OH 43201; Ph 614-299-5522 or 800-
JGA SOUTHERN ROOF CENTER, 2200 Cook Dr.,
STRUCTURAL SLATE CO., 222 East Main St., Pen 666-7445; Fx 614-299-7100;
Atlanta, GA 30340; Ph 770-447-6466; Fx 770-
Argyl, PA 18072; Ph 610-863-4141 or 800-677- tile@durableslate.com; www.durableslate.com
840-9001; jimo@jgacorp.com; www.jgacorp.com
5283; Fx 610-863-7016; ssco1@ptd.net; ECHEGUREN SLATE, INC., 1495 Illinois St., San
ILLINOIS
www.structuralslate.com Francisco, CA 94107; Ph 415-206-9343; Fx 415-
MORTENSON ROOFING CO., 9505 Corsair Rd.,
WILLIAMS AND SONS SLATE AND TILE, 6596 206-9353; slate@echeguren.com; www.eche-
Frankfort, IL 60423; Ph 815-464-7300; Fx815-
Sullivan Trail, Wind Gap PA 18091; Ph: 610- guren.com
464-7850; www.mortensonroofing.com
863-4161; Fax: 610-863-8128; www.williamss- EMACK SLATE COMPANY, INC., 9 Office Park
*RENAISSANCE ROOFING, INC., PO Box 5024,
late.com/index.htm; wmsslate@enter.net Circle, Suite 120, Birmingham, AL 35223; Ph
Rockford, IL 61125; Ph 815-547-1725 or 815-
TEXAS 205-879-3424; Fx 205-879-5420; jim@emack-
874-5695 or 800-699-5695; Fx 815-547-1425;
BURLINGTON NATSTONE INC., 2701C W. 15th St., slate.com; www.emackslate.com
info@claytileroof.com; www.claytileroof.com
Ste. 505, Plano, TX 75075; Ph 972-985-9182; Fx

296 The Slate Roof Bible — Second Edition

SALVAGED ROOFING SLATE (CONTINUED) ts@tilesearch.net; www.tilesearch.net Calgary ALB Canada T2G 3C7; Ph 403-287-7763
VERMONT RECYCLED SLATE; PO Box 71; Fair or 888-67-SLATE; Fx 403-287-7736;
GENUINE SLATE, P.O. Box 235, Whitehall, NY
Haven, VT 05743; Ph 802-265-4506; www.useds- zimmer@universalslate.com; www.universals-
12887; store 1209 Prospect St., Fair Haven, VT
late.com; late.com
05743; Ph 802-265-8300;
*VERMONT SPECIALTY SLATE, INC., PO Box 4,
info@genuineslate.com; www.genuineslate.com USED CERAMIC ROOF TILE
Brandon, VT 05733; Store 855 North Street,
GILBERT & BECKER CO., INC., 16-24 Clapp St., *ALLUVIUM CONSTRUCTION, 200 Lake Shore
Forestdale, VT 05745; Ph 1-866-US-SLATE; Fx
Dorchester, MA 02125; Ph 617-265-4343; Fx Drive Marlton, NJ 08053; Ph 856-767-2700; Fx
802-247-4209; info@vtslate.com;
617-265-0936; info@gilbertandbecker.com; 856-768-7766;
www.vtslate.com
www.gilbertandbecker.com alluviumconstruction@comcast.net; www.his-
VINTAGE SLATE, 265 Furnace St, Poultney, VT
*GREENSTONE SLATE, PO Box 134, 325 Upper toricroofs.com, www.thesteeplepeople.com
05764; Phone: 802-287-2559; Cell: 802-342-0915;
Rd., Poultney, VT 05764, Ph 802-287-4333; Fx DURABLE SLATE CO., 1050 N. Fourth St.,
info@vintageslate.com; http://www.vintages-
802-287-5720; info@greenstoneslate.com; Columbus OH 43201; Ph 614-299-5522 or 800-
late.com
www.greenstoneslate.com 666-7445; Fx 614-299-7100;
*JOSEPH JENKINS INC., 143 Forest Lane, Grove tile@durableslate.com; www.durableslate.com
NEW CERAMIC ROOFING TILE
City, PA 16127; Ph 814-786-9085 or 866-641- EMACK SLATE COMPANY, INC., 9 Office Park
*ALLUVIUM CONSTRUCTION, 200 Lake Shore Dr.,
7141; Fx 814-786-8209; mail@joseph- Circle, Suite 120, Birmingham, AL 35223; Ph
Marlton, NJ 08053; Ph 856-767-2700; Fx 856-
jenkins.com; www.slateroofcentral.com 205-879-3424; Fx 205-879-5420; jim@emack-
768-7766; alluviumconstruction@comcast.net;
JUST SLATE, 208 Frog Hollow Rd., Brandon, VT slate.com; www.emackslate.com
www.historicroofs.com;
05733; Ph/Fx 802-247-8145; justslate1@aol.com GENUINE SLATE, P.O. Box 235, Whitehall, NY
*AMERICAN SLATE CO., 1900 Olympic Blvd., Ste.
JOHN KING, 133 Hayfield Ct., Wilmington, NC 12887; store 1209 Prospect St., Fair Haven, VT
200 Walnut Creek, CA 94596; Ph 925-977-4880
28411; Ph 910-686-9394; Fx 910-853-3812; 05743; Ph 802-265-8300;
or 800-553-5611; Fx 925-977-4885;
jkingco1@earthlink.net info@genuineslate.com;
slatexpert@americanslate.com; www.americans-
LANTZ SLATE ROOF REPAIR, 2431 Creekhill Rd., www.genuineslate.com
late.com
Lancaster, PA 17601; Ph 717-656-2620; Fx 717- GILBERT & BECKER CO., INC., 16-24 Clapp St.,
EMACK SLATE COMPANY, INC., 9 Office Park
656-7727 Dorchester, MA 02125; Ph 617-265-4343; Fx
Circle, Suite 120, Birmingham, AL 35223; Ph
MORTENSON ROOFING CO., 9505 Corsair Rd., 617-265-0936; info@gilbertandbecker.com;
205-879-3424; Fx 205-879-5420; jim@emack-
Frankfort, IL 60423; Ph 815-464-7300; Fx 815- www.gilbertandbecker.com
slate.com; www.emackslate.com
464-7850; www.mortensonroofing.com JOHN KING, 133 Hayfield Ct., Wilmington, NC
GENUINE SLATE, P.O. Box 235, Whitehall, NY
NORTH AMERICAN BÖCKER, 302 West Lane St.., 28411; Ph 910-686-9394; Fx 910-853-3812;
12887; store 1209 Prospect St., Fair Haven, VT
Raleigh, NC 27603; Ph 800-624-8076; Fx 919- jkingco1@earthlink.net
05743; Ph 802-265-8300;
832-8439; info@nabocker.com; MORTENSON ROOFING CO., 9505 Corsair Rd.,
info@genuineslate.com;
www.nabocker.com Frankfort, IL 60423; Ph 815-464-7300; Fx 815-
www.genuineslate.com
NOSAK IMPROVEMENTS, INC., 2121 E. Ute St. 464-7850; www.mortensonroofing.com
JGA SOUTHERN ROOF CENTER, 2200 Cook Dr.,
Tulsa, OK 74110; Ph 918-230-0005, 918-599- NOSAK IMPROVEMENTS, INC., 2121 E. Ute St.
Atlanta GA 30340; Ph 770-447-6466 or 800-763-
0368; Fx 918-599-0277; paulnosak13@aol.com Tulsa, OK 74110; Ph 918-230-0005, 918-599-
0118; Fx 770-840-8941; jimo@jgacorp.com;
OLD WORLD DISTRIBUTORS, 6101 West KL Ave., 0368; Fx 918-599-0277; paulnosak13@aol.com
www.jgacorp.com
Kalamazoo, MI 49009; Ph 269-372-3916; Fx 269- OLD WORLD DISTRIBUTORS, 6101 West KL Ave.
LUDOWICI ROOF TILE, PO Box 69; New
372-9852; owdist@net-link.net; www.oldworld- Ste. 2, Kalamazoo, MI 49009; Ph 269-372-3916;
Lexington, OH 43764; Ph 800-917-8998;
didtributors.com Fx 269-372-9852; owdist@net-link.net;
teresa.spencer@ludowici.com;
*RENAISSANCE ROOFING, INC., PO Box 5024, www.oldworlddistributors.com
www.ludowici.com
Rockford, IL 61125; Ph 815-547-1725 or 815- *RENAISSANCE ROOFING, INC., PO Box 5024,
MORTENSON ROOFING CO., 9505 Corsair Rd.,
874-5695 or 800-699-5695; Fx 815-547-1425; Rockford, IL 61125; Ph 815-547-1725 or 815-
Frankfort, IL 60423; Ph 815-464-7300; Fx 815-
info@claytileroof.com; www.claytileroof.com 874-5695 or 800-699-5695; Fx 815-547-1425;
464-7850; www.mortensonroofing.com
*RECLAIMED ROOFS, INC., 7454 Lancaster Pike info@claytileroof.com; www.claytileroof.com
NORTHERN ROOF TILES, 50 Dundas St. E.,
#328, Hockessin, DE 19707; Ph (302) 369-9187; ROOF CENTER, THE, 9055 Comprint Ct., Ste. 300,
Dundas, ON Canada L9H 7K6 Ph 905-689-4035,
Fx (302) 397-2742; Mobile (302) 388-1155; Gaithersburg, MD 20877; Ph 301- 548-0548 or
888-678-6866; Fx 905-689-7099; sales@nothern-
doug@reclaimedroofs.com; www.reclaime- 800-503-5500; Fx 301-548-0828; roof@roofcen-
rooftiles.com; www.northernrooftiles.com
droofs.com ter.com; www.roofcenter.com
OLD WORLD DISTRIBUTORS, 6101 West KL Ave.
ROOF CENTER, THE, 9055 Comprint Ct., Ste. 300, ROOF TILE AND SLATE COMPANY, THE, 1209
Ste. 2, Kalamazoo, MI 49009; Ph 269-372-3916;
Gaithersburg, MD 20877; Ph 301-548-0548 or Carroll Ave., Carrollton, TX 75006; Ph 972-446-
Fx 269-372-9852; owdist@net-link.net;
800-503-5500; Fx 301-548-0828; roof@roofcen- 0005 or 800-446-0220; Fx 972-242-1923; rtsc-
www.oldworlddistributors.com
ter.com; www.roofcenter.com dow@aol.com; www.claytile.com
*RENAISSANCE ROOFING, INC., PO Box 5024,
ROOF TILE AND SLATE COMPANY, THE, 1209 RYAN CONTRACTING & ROOFING, 360 Merrimack
Rockford IL 61125; Ph 815-547-1725 or 815-874-
Carroll St., Carrollton, TX 75006; Ph 972-446- Street, Bldg #5, Lawrence, MA 01843; Ph 888-
5695 or 800-699-5695; Fx 815-547-1425;
0005 or 800-446-0220; Fx 972-242-1923; rtsc- ROOF-SOS or 978-557-9413
info@claytileroof.com; www.claytileroof.com
dow@aol.com; www.claytile.com TILE MAN, INC., THE, 520 Vaiden Rd., Louisberg,
ROOF CENTER, THE, 9055 Comprint Ct., Ste. 300,
RYAN CONTRACTING & ROOFING, 360 Merrimack NC 27549; Ph 919-853-6923 or 888-263-0077; Fx
Gaithersburg, MD 20877; Ph 301-548-0548; or
Street, Bldg #5, Lawrence, MA 01843; Ph 888- 919- 853-6634; info@thetileman.com;
800-503-5500; Fx 301-548-0828; roof@roofcen-
ROOF-SOS or 978-557-9413 www.thetileman.com
ter.com; www.roofcenter.com
SLATE & COPPER CO., 1024 W. Fourth St., Erie, *TILE ROOFS, INC., 9505 Corsair Rd., Frankfort,
ROOF TILE AND SLATE COMPANY, THE, 1209
PA 16057; Ph 814-455-7430; Fx 267-200-0800; IL 60423; Ph 708-479-4366 or 888-708-TILE; Fx
Carroll Ave., Carrollton, TX 75006; Ph 972-446-
slatecut@aol.com; www.slateandcopper.com 708-479-7865; tileroofs@aol.com;
0005 or 800-446-0220; Fx 972-242-1923; rtsc-
SLATEWORKS ROOFING, 117 Elizabeth Street, www.tileroofs.com
dow@aol.com; www.claytile.com
Evans City, PA 16033; Contact: Ron Kugel; Ph: TILESEARCH, INC., 216 James St., Roanoke, TX
ROOF TILE MANAGEMENT, INC., 2535 Drew Rd.,
724-538-3538; Cell: 724-316-7702; Fax: 724-538- 76262; Ph 817-491-2444; Fx 817-491-2457;
Mississauga Ontario Canada L4T 1G1; Ph 905-
3538 ts@tilesearch.net; www.tilesearch.net
672-9992; Fx 905-672-9902; www.rooftileman-
TARAN BROTHERS SLATE COMPANY, 2522
agement.com
Vermont Route 30 N, North Poultney, VT 05764; SLATE TOOLS & EQUIPMENT
SOURCE PRODUCTS GROUP INC., 16000 Huron St.,
802-265-3220 (“T” = Tools; “E” = Equip.; “F” = Flashing)
Broomfield, CO 80020; Ph 303-280-9595; Fx
TILE MAN, INC., THE, 520 Vaiden Rd., Louisberg ABC SUPPLY, One ABC Pkwy, Beloit, WI 53511;
303-280-2600; www.petraslate.com; www.tileroof-
NC 27549; Ph 919-853-6923 or 888-263-0077; Fx Ph: 608-362-7777 or 800-786-1210; Fx 608-362-
ing.com
919-853-6634; info@thetileman.com; 6215; www.abcsupply.com; (T, E, F)
TEJAS BORJA USA; 401 Redland Rd., Homestead,
www.thetileman.com ACRO BUILDING SYSTEMS, 2200 W. Cornell St.,
FL 33030; Ph 305-594-4224 or 800-830-TILE;
*TILE ROOFS, INC., 9505 Corsair Rd., Frankfort, Milwaukee, WI 53209; Ph 414-445-8787 or 800-
Fx 305-242-6595; adam@tejasborja-usa.com;
IL 60423; Ph 708-479-4366 or 888-708-TILE; Fx 267-3807; Fx 414-445-8792; info@acrobuild-
www.tejasborja-usa.com
708-479-7865; tileroofs@aol.com; ingsystems.com; www.acrobuildingsystems.com;
TILESEARCH, INC., 216 James St., Roanoke TX
www.tileroofs.com (E - roof brackets, ladder accessories)
76262; Ph 817-491-2444; Fx 817-491-2457;
TILESEARCH, INC., 216 James St., Roanoke, TX AJC HATCHET CO., 1227 Norton Rd., Hudson,
ts@tilesearch.net; www.tilesearch.net
76262; Ph 817-491-2444; Fx 817-491-2457; OH 44236; Ph 330-655-2851 or 800-428-2438; Fx
UNIVERSAL SLATE INTL., INC., 3821 9th St. SE,

The Slate Roof Bible — Second Edition 297

 SLATE TOOLS & EQUIPMENT (CONT.) worlddistributors.com (T, E, F) www.follansbeeroofing.com
P. F. FREUND & CLE. GMBH., Hahnerberger Str. INTERSTATE MANUFACTURING AND SUPPLY, 6363
330-650-1000; info@ajctools.com;
94-96, Postfach 150 125, Wuppertal, Germany D- Highway #7, St. Louis Park, MN 55416; Ph 800-
www.ajctools.com; (T - slate ripper)
42349; Ph (49) 0202-409-29-0; Fx (49) 0202-409- 328-6766 or 952-926-2611; Fx 952-926-2313
BENO J. GUNDLACH CO., 211 North 21st St.,
2929; info@freund-cie.com; www.freund-cie.com *JOSEPH JENKINS, INC., 143 Forest Lane, Grove
Belleville, IL 62226; Ph 618-233-1781; Fx 618-
(T) City, PA 16127; Ph 814-786-9085 or 866-641-
233-3636; www.benojgundlachco.com;
*PENN BIG BED, PO Box 184, 8450 Brown St., 7141; Fx 814-786-8209; mail@joseph-
contact.us@ benojgundlachco.com; (T - cutter)
Slatington, PA 18080; Ph 610-767-4601; Fx 610- jenkins.com; www.slateroofcentral.com
*BERGER BROS. CO., 805 Pennsylvania Blvd.,
767-9252; www.pennbigbedslate.com (T) OLD WORLD DISTRIBUTORS, 6101 West KL Ave.,
Feasterville, PA 19053; Ph 215-355-1200 or 800-
REIMANN & GEORGER CORP., PO Box 681, Kalamazoo, MI 49009; Ph 269-372-3916; Fx 269-
523-8852; Fx 215-355-7738; berger@berger-
Buffalo, NY 14240; Ph 716-895-1156; Fx 716- 372-9852; owdist@net-link.net; www.oldworld-
brothers.com; www.bergerbrothers.com or
895-1547; sales@rgcproducts.com; www.rgcprod- distributors.com
www.snowbrakes.com (E, F)
ucts.com (E - ladder hooks) ROOF CENTER, THE, 9055 Comprint Ct., Ste. 300,
CARL KAMMERLING AND CO., PO Box 10 02 40,
*RENAISSANCE ROOFING, INC., PO Box 5024, Gaithersburg, MD 20877; Ph 301-548-0548 or
D-42002 Wuppertal, Bendahler Str. 110,
Rockford, IL, 61125; Ph 815-547-1725 or 815- 800-503-5500; Fx 301-548-0828; roof@roofcen-
Wuppertal(barmen), Germany 42285; Ph
874-5695 or 800-699-5695; Fx 815-547-1425; ter.com; www.roofcenter.com
(49)0202-8903-0; Fx (49)0202-8071-5 (T)
info@claytileroof.com; www.claytileroof.com (T) ROOF TILE MANAGEMENT, INC., 2535 Drew Rd.,
CASSADY-PIERCE CO., 2295 Preble Ave., Pgh., PA
ROOF CENTER, THE, 9055 Comprint Ct., Ste. 300, Mississauga, Ontario CANADA L4T 1G1; Ph
15233; Ph 412-321-8987 or 800-227-7239; Fx 412-
Gaithersburg, MD 20877; Ph 301-548-0548 or 905-672-9992; Fx 905-672-9902; www.rooftilem-
321-4076; www.cassadypierce.com (T, E, F)
800-503-5500; Fx 301-548-0828; roof@roofcen- anagement.com
CEKA WORKS, LTD., Pwllheli LL53 5LH North
ter.com; www.roofcenter.com (T, E, F) SLATE & COPPER SALES CO., 201 German St.,
Wales; Ph (44)01758-70-10-70; Fx (44)1758-70-
ROOF TILE AND SLATE COMPANY, THE, 1209 Erie, PA 16507; Ph 814-455-7430; Fx 267-200-
10-90; sales@ck-tools.com; www.ck-tools.com (T)
Carroll Ave., Carrollton, TX 75006; Ph 972-446- 0800; sales@slateandcopper.com; www.slateand-
ECHEGUREN SLATE, INC., 1495 Illinois St., San
0005 or 800-446-0220; Fx 972-242-1923; rtsc- copper.com
Francisco, CA 94107; Ph 415-206-9343; Fx 415-
dow@aol.com; www.claytile.com (T) UNIMET METAL SUPPLY, 557 Main Street, Orange,
206-9353; slate@echeguren.com; www.eche-
SIEVERT INDUSTRIES, INC., 5255 Zenith Parkway, NJ 07050; Ph 800-526-4004; Fx 973-673-6477
guren.com (T)
Loves Park, IL 61111; Ph 877-639-1319; Fx 815- WILLIAM METALS AND WELDING., 8052 State
ESTWING MANUFACTURING CO., 2647 Eighth St.,
Rockford, IL 61109; Ph 815-397-9558; Fx 815- 639-1320; mmelito@sievertindustries.com; Street, Garrettsville, OH 44231-1023; Ph 800-
397-8665; sales@estwing.com; www.estwing.com www.sievertindustries.com (soldering equip- 842-3762; Fx 330-527-2748
(T -hammers, prybars, chisels) ment)
*EVERGREEN SLATE CO., LLC., 68 E. Potter Ave., *JOHN STORTZ AND SON, INC., 210 Vine St., NAILS, RIVETS, SLATE HOOKS
Granville, NY 12832; Ph 518-642-2530; Fx 518- Philadelphia, PA 19106; Ph 215-627-3855 or 888- DORR WHOLESALE SUPPLY, 209 Riverside Heights,
642-9313; slate@evergreenslate.com; www.ever- 847-3456; Fx 215-627-6306; john@stortz.com; Manchester Center, VT 05255; Ph 802-362-2344
greenslate.com (T) www.stortz.com (T, E - hammers, rippers, cut- (slate hooks)
FLAME ENGINEERING, INC., PO Box 577 Lacrosse, ters, tongs, etc.) INTERSTATE MANUFACTURING AND SUPPLY, 6363
KS 67548; Ph 785-222-2873, 800-255-2469; Fx STRUCTURAL SLATE CO., 222 East Main St., Pen Highway #7, St. Louis Park, MN 55416; Ph 800-
785-222-3619; flame@flameengineering.com ; Argyl, PA 18072; Ph 610-863-4141 or 800-677- 328-6766 or 952-926-2611; Fx 952-926-2313
www.flameengineering.com (T - torches, dragon 5283; Fx 610-863-7016; ssco1@ptd.net; (nails, rivets)
wagons) www.structuralslate.com (T) *JOSEPH JENKINS, INC., 143 Forest Lane, Grove
FULTON CORP., 303 8th Ave., Fulton, IL 61252; TILESEARCH, INC., 216 James St., Roanoke, TX City, PA 16127; Ph 814-786-9085 or 866-641-
Ph 800-252-0002; Fx 815-589-4433; www.fulton- 76262; Ph 817-491-2444; Fx 817-491-2457; 7141; Fx 814-786-8209; mail@joseph-
corp.com (E - ladder hooks) ts@tilesearch.net; www.tilesearch.net (T) jenkins.com; www.slateroofcentral.com
GILBERT & BECKER CO., INC., 16-24 Clapp St., VERMONT SPECIALTY SLATE, PO Box 4, Brandon, (nails, rivets, slate hooks)
Dorchester, MA 02125; Ph 617-265-4343; Fx VT 05733; store 855 North St., Forestdale, VT *NEW ENGLAND SLATE CO., 1385 US Rt 7,
617-265-0936; info@gilbertandbecker.com; 05745; Ph 1-866-US SLATE or 802-247-6615; Fx Pittsford, VT 05763; Ph 802-247-8809 or 1-888-
www.gilbertandbecker.com (T - hammer, stakes, 802-247-4209; info@vtslate.com; NE-SLATE; Fx 802-247-0089;
ripper) www.vtslate.com (T) slate@neslate.com; www.neslate.com (nails, slate
*GREENSTONE SLATE, PO Box 134, 325 Upper *VERMONT STRUCTURAL SLATE CO., INC., Box 98, hooks)
Rd., Poultney, VT 05764; Ph 802-287-4333; Fx 3 Prospect Ave., Fair Haven, VT 05743; Ph 802- OLD WORLD DISTRIBUTORS, 6101 West KL Ave.
802-287-5720; info@greenstoneslate.com; 265-4933 or 800-343-1900; Fx 802-265-3865; Ste. 2s, Kalamazoo, MI 49009; Ph 269-372-3916;
www.greenstoneslate.com (T) info@vermontstructuralslate.com; www.ver- Fx 269-372-9852; owdist@net-link.net; www.old-
GT PRODUCTS, INC., 86 Union Street, Mineola, montstructuralslate.com (T) worlddistributors.com (nails, slate hooks)
NY 11501; Ph 516-625-1870; Fx 516-625-1226; WILLIAMS AND SONS SLATE AND TILE, 6596 *RENAISSANCE ROOFING, INC., PO Box 5024,
gtproduct@aol.com; www.geotechproduct.com Sullivan Trail, Wind Gap, PA 18091; Ph 610-863- Rockford, IL 61125; Ph 815-547-1725 or 815-
(T- hammer, cutters, rippers) 4161; Fx 610-863-8128; wmsslate@enter.net (T) 874-5695 or 800-699-5695; Fx 815-547-1425;
INTERSTATE MANUFACTURING & SUPPLY, 6363 info@claytileroof.com; www.claytileroof.com
Highway #7, St. Louis Park, MN 55416; Ph 800- FLASHING METAL
(nails, slate hooks)
328-6766; Fx 952-926-2313 (E, F) ABC SUPPLY, One ABC Pkwy, Beloit, WI 53511;
*SLATE ROOF SPECIALITIES, PO Box 362, Stowe,
*JOSEPH JENKINS, INC., 143 Forest Lane, Grove Ph: 608-362-7777 or 800-786-1210; Fx 608-362-
VT 05672; 802-498-4158 (slate hooks)
City, PA 16127; Ph 814-786-9085 or 866-641- 6215; www.abcsupply.com
SWAN SECURE PRODUCTS, INC., 7525 Perryman
7141; Fx 814-786-8209; mail@joseph- *BERGER BROS. CO., 805 Pennsylvania Blvd.,
Court, Baltimore, MD 21226; Ph 410-360-9100;
jenkins.com; www.slateroofcentral.com (T, E,F) Feasterville, PA 19053; Ph. 215-355-1200 or 800-
Fx 410-360-2288; www.swansecure.com (nails)
JGA SOUTHERN ROOF CENTER, 2200 Cook Dr., 523-8852; Fx. 215-355-7738; berger@berger-
WIRE WORKS, INC., 2910 E. Commercial,
Atlanta, GA 30340; Ph 770-447-6466 or 800-763- brothers.com; www.bergerbrothers.com or
Pahrump, NV 89048; Ph 800-341-8828, 775-751-
0118; Fx 770-840-8941; jimo@jgacorp.com; www.snowbrakes.com
5555; Fx 775-751-9250; staff@wire-works-
www.jgacorp.com (T) CAMBRIDGE-LEE INDUSTRIES INC., 475 Jersey
inc.com; www.wire-works-inc.com (nails, slate
JUST SLATE, 208 Frog Hollow Rd., Brandon, VT Ave., New Brunswick, NJ 08903; Ph 800-852-
hooks)
05733; Ph/Fx 802-247-8145; justslate1@aol.com 2885; Fx 732-846-8476
(T) CASSADY-PIERCE CO., 2295 Preble Ave., Pgh., PA
* see ad following this section
*NEW ENGLAND SLATE CO., 1385 US Rt. 7, 15233; Ph 412-321-8987 or 800-227-7239; Fx 412-
Pittsford, VT 05763; Ph 802-247-8809 or 888- 321-4076; www.cassadypierce.com
NE-SLATE; Fx 802-247-0089; COPPER SALES (UNA-CLAD), 1001 Lund Blvd.,
slate@neslate.com; www.neslate.com (T) Anoka, MN 55303; Ph 763-576-9595 or 800-426-
7737; Fx 763-576-9596; www.unaclad.com
For the latest up-to-date
NORTH AMERICAN BÖCKER, 302 West Lane St.,
Raleigh, NC 27603; Ph 800-624-8076; Fx 919- FLORIDA METAL PRODUCTS, PO Box 6310, listings visit
832-8493; info@nabocker.com; Jacksonville, FL 32236; Ph 904-783-8400 or 800-
www.nabocker.com (T, E) 634-3937; Fx 904-783-8403; www.flamco.com; slateroofcentral.com
OLD WORLD DISTRIBUTORS, 6101 West KL Ave. flamco@flamco.com (ridge iron and copper)
Ste. 2, Kalamazoo, MI 49009; Ph 269-372-3916; FOLLANSBEE STEEL, PO Box 610, Follansbee, WV
Fx 269-372-9852; owdist@net-link.net; www.old- 26037; 800-624-6906; folrfg@lbcorp.com;

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 INDUSTRY SPOTLIGHT
CAMARA SLATE
Reprinted from Traditional Roofing, Spring, 2002 (www.traditionalroofing.com)
by Joseph Jenkins

The “Slate Valley” of western Vermont is well-known world wide for

its high quality, multi-colored roofing slates — some of the best slates
in the world come from here. Stretching for 25 miles from north to
south, the valley is dotted by numerous quarries of stone that glistens
purple, red, green, gray, or black; stone that has been historically
proven to withstand the test of time on the roofs of buildings. Many
rugged men work these quarries, wrestling from the Earth the massive
stone slabs that will be skillfully worked by hand into individual roofing
shingles.
Dave Camara is one of those workers. President and founder of
Camara Slate Inc., Dave and four of his sons now operate three work-
ing quarries spread throughout the valley. Camara Slate also owns an
additional dozen or so area quarries for possible future development.
Dave started in the business by salvaging slates from old buildings
in the early 80s, trucking the salvaged slates around the nation, and
back-hauling steel building components. His slate salvaging business
Dave Camara and a supply of “sea expanded rapidly, allowing, from year to year, the purchase of bigger
green” roofing slates awaiting shipment trucks and more slates, and finally his first slate quarry. Truly a tale of
at the Camara Slate Co., stockyard on Rt hard work, determination, and ingenuity, Dave Camara, with the help
22A just outside Fair Haven, Vermont. of his family, has risen to the top of the field in the slate roofing manu-
facturing business. Camara Slate now offers for sale new slates in a
rainbow of colors: gray, unfading red, Spanish black, unfading green, unfading mottled purple, “sea green,”
purple, and Vermont gray black. They also produce slate flooring, flagstones, cladding, sills and copings,
treads and risers, countertops, and structural slate in a variety of colors. Pallets of salvaged slates can still
be found in the Camara stockyard on Route 22A just outside Fair Haven, although these are now dwarfed
by the extensive inventory of new slates that fill the yard.
Camara and his sons express a strong pride in their products; their attention to detail and concern
for quality and reputation is remarkable. Shawn Camara (age 30) runs the Blissville Quarry at the northern
end of the valley, working alongside the other men there, splitting slates and keeping an eye on quality
control. Here they produce the unfading slates: mottled green and purple, unfading gray and unfading
green. Dave Camara Jr. (age 33) works in the pit at the Blissville quarry
— an experienced “rockman,” responsible for selecting the high-quality
stone that is needed for splitting into roofing shingles.
Mike Camara (age 32) runs the West Pawlet quarry at the
southern end of the valley, while Danny (age 26) is the rockman there.
Here they produce Vermont black slates, semi-weathering gray, and
semi-weathering green slates. From their Wells quarry, in the center of
the valley, also come sea green and semi-weathering gray slates.
Camara slates are shipped throughout the United States includ-
ing Hawaii, as well as to Canada. Their roofing slates have the tradi-
tional punched nail holes as opposed to non-countersunk drilled holes
that are found on lower quality slates. The holes are punched to allow
for either a three inch or four inch headlap. Camara’s slate prices are
very competitive; their product quality appears to be quite high; their
attention to detail and concern for customer satisfaction is genuine, and
they offer information that is no-nonsense and straightforward. As a
result, Camara Slate is gaining an impressive reputation among roofing
contractors in the United States. They’re certainly worth a look when
considering the purchase of virtually any slate product. Shawn Camara splitting a slate block into
advertisement
roofing slates at the Blissville Quarry.

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 The Twelfth Century
Slate Roofing Company
Douglas L. Raboin

Slate Roof
Specialist
10 Spring Valley Road
Burlington, Massachusetts 01803
(617) 666-3888
MA Reg.# 100693

PENN BIG BED SLATE CO., INC.

MINERS & MANUFACTURERS SINCE 1934

Roofing Slate, Structural Slate, Sills, Treads,

Risers, Fireplace Facings, Floor Tile, Turkey
Calls, Craft Slate, Blackboards, etc.
WWW.PENNBIGBEDSLATE.COM
email: pennbbs@aol.com
MAILING ADDRESS: QUARRIES:
P.O. Box 184 Slatedale and Pen Argyl
Slatington, PA 18080

PHONE (610) 767-4601 • FAX (610) 767-9252

HISTORICAL ROOF TILES

Largest stock in U.S.
• Our inventory dates to the late
1800s. It includes new tile and tiles
no longer produced.
• We sell in all quantities and ship
throughout the U.S. and also pur-
“Your Tile, Slate, and chase salvaged materials
Copper Roof
Specialists”
For a FREE brochure, write or call us today:
TILE ROOFS, INC.
9505 Corsair Road, Frankfort, IL 60423
(888) 708-TILE • fax: (708) 479-7865
www.tileroofs.com

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306 The Slate Roof Bible — Second Edition
 Quarrier •
Box 98, 3 Prospect Street
All colors, sizes and thicknesses •
Fair Haven, VT 05743 USA
Specializing in unfading colors • Phone: 802-265-4933
ACE award winner for highest • Toll free: 800-343-1900
quality slate Fax: 802-265-3865
Competitive prices & lead times •
email: info@vermontstructuralslate.com
Large inventory • web: www.vermontstructuralslate.com

The Slate Roof Bible — Second Edition 307

 JOHN STORTZ AND SON, INC.

210 Vine St.,

Philadelphia, PA 19106
Phone: 215-627-3855
or 888-847-3456
Fax: 215-627-6306
email:jcstool@stortz.com
www.stortz.com
Manufacturer/Distributor of Slate Rippers, Hammers,
Cutters and Sheet Metal Roofing Hand Tools.

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