Dimension Stone

Design Manual
Version VIII

Produced and Published by the

Marble Institute of America
www.marble-institute.com
Disclaimer: This manual contains general guidelines. The Marble Institute of America and its Member
companies are not responsible for any use or misuse that causes damage of any kind, including loss of
rights, material, and personal injury alleged to be caused directly or indirectly by the information contained
in this manual.

© 2016 Marble Institute of America (Chapter 21, 22, Glossary, Appendix and Index)
© 2011 Marble Institute of America (Chapter 17, Glossary and Index)
© 2010 Marble Institute of America (Chapters 13, 14, 15, and Index)
© 2007 Marble Institute of America (All other Chapters)

All rights reserved. No part of this document may be reproduced or transmitted in any form or by means electronic
or mechanical, including photocopy, recording, or by an information storage and retrieval system, without written
permission from the Marble Institute of America.
Table of Contents

Introduction
Foreword................................................................................ i
Acknowledgements ................................................................... ii
Limitations on Use and Disclaimer ................................................. iii
Organization Web Site ............................................................... iv
Green Building Movement ........................................................... v
Suggested Warranty Provision/Disclaimer ....................................... xii
Suggested Residential Contract ..................................................... xiii
MIA Code of Ethics ................................................................... xiv
MIA Membership ...................................................................... xv
Sample Specification Language ...................................................... xvii

CHAPTER 1 The Geology of Stone .................................................................... 1-1

CHAPTER 2 Standards and Specifications for Stone Products ......................... 2-1

CHAPTER 3 Dimension Stone Selection ........................................................... 3-1

CHAPTER 4 Stone Testing ................................................................................. 4-1

CHAPTER 5 Granite .......................................................................................... 5-1

CHAPTER 6 Limestone ...................................................................................... 6-1

CHAPTER 7 Marble and Onyx .......................................................................... 7-1

CHAPTER 8 Quartz-Based Stone ...................................................................... 8-1

CHAPTER 9 Serpentine ..................................................................................... 9-1

CHAPTER 10 Slate ............................................................................................... 10-1

CHAPTER 11 Soapstone ...................................................................................... 11-1

CHAPTER 12 Travertine...................................................................................... 12-1

CHAPTER 13 Installation - General Information ............................................... 13-1

CHAPTER 14 Horizontal Surfaces ...................................................................... 14-1

Introduction 14-1
Exterior Stone Paving 14-5
Interior Stone Flooring 14-7
Stone Thresholds 14-11
Stone Stair Treads 14-13

 2016 Marble Institute of America Table of Contents • Page 1

Table of Contents, continued

CHAPTER 15 Vertical Surfaces............................................................................ 15-1

Installation Notes 15-1
Exterior Stone Veneer 15-7
Interior Wall Cladding 15-11
Interior Stone Base 15-15
Stone Soffits 15-17
Stone Fireplace Facings 15-19

CHAPTER 16 Wet Areas ...................................................................................... 16-1

Installation Notes 16-1
Stone Toilet Partitions 16-3
Stone Urinal Partitions 16-4
Stone Slab Shower Partitions 16-5
Stone Slab Residential Showers, Steam
Rooms & Steam Showers 16-7
Stone Tile Residential Showers, Steam
Rooms & Steam Showers 16-10
Accessories and Stone Penetrations 16-12

CHAPTER 17 Counter and Lavatory Tops .......................................................... 17-1

CHAPTER 18 Coping and Stools ......................................................................... 18-1

Exterior Cubic Stone Coping and Walls 18-1
Thin Stone Stools and Cubic Sills 18-3

CHAPTER 19 Stone Furniture ............................................................................. 19-1

CHAPTER 20 Stone-Faced Veneer Precast Concrete .......................................... 20-1

CHAPTER 21 Restoration and Maintenance ...................................................... 21-1

Stone Geology 21-1
Stone Identification 21-5
Stone Behavioral Groups 21-11
Diagnostics 21-17
Equipment 21-27
Repairs 21-39
Repairs Adhesives Chart 21-50
Restorative Processes 21-51
Sealers 21-67
Maintenance 21-75
Commercial/Historic 21-85
Troubleshooting 21-89
Additional Learning Resources 21-121

Page 2 • Table of Contents  2016 Marble Institute of America

Table of Contents, continued

CHAPTER 22 Tolerances in the Dimension Stone Industry ............................... 22-1

Chart of Tolerances 22-5
Graphic Interpretation of Tolerances 22-9

CHAPTER 23 Glossary of Common Stone Terms ................................................ 23-1

Appendix ............................................................................................................. 24-1

English - Metric Conversion Tables 24-1
Slab Production Table 24-2
Mohs Scale 24-2
Additional MIA Resources 24-3
ASTM Classification Index 24-4

Index .................................................................................................................... 25-1

 2016 Marble Institute of America Table of Contents • Page 3

Directory of Detail Drawings

CHAPTER 7 Marble and Onyx

Veneer Cutting and Patterns ........................................ 7-D-1,-2,-3

CHAPTER 13 Installation
Typical Anchors, Accessories ....................................... 13-D-1,-2,-3

CHAPTER 14 Horizontal Surfaces

Exterior Stone Paving................................................. 14-D-1,-2
Interior Stone Flooring ............................................... 14-D-3
Radiant Heat Details .................................................. 14-D-4
Stone Thresholds ...................................................... 14-D-5
Stone Stair Treads ..................................................... 14-D-6,-7
Typical Details / Interior Treads ................................... 14-D-8

CHAPTER 15 Vertical Surfaces

Exterior Stone Veneer
Attachment Details .................................................... 15-D-1,-2,-3,
.................................................................... 15-D-4,-5
Relief Details with Rebated Bearings .............................. 15-D-6
Relief Details with Non-Rebated Bearings ........................ 15-D-7
Restraint Anchorage .................................................. 15-D-8
Restraint Anchorage Details ......................................... 15-D-9
Typical Corners, Expansion Joints, Reglets ...................... 15-D-10
Interior Stone Wall Veneer
Wall Facing Details.................................................... 15-D-11,-12,-13,
Free-Standing Column Details ...................................... 15-D-14,-15,-16
Crypt with Bracket and Rosette Detail ............................ 15-D-17
Crypt with Bolt and Rosette Fastenings Detail ................... 15-D-18
Crypt with Stile and Rail Detail..................................... 15-D-19
Corner Details ......................................................... 15-D-20
Interior Stone Base
Typical Details ......................................................... 15-D-21
Stone Soffits
Exterior Soffit Details ................................................ 15-D-22
Stone Fireplace Facings
Typical Details ......................................................... 15-D-23,-24
CHAPTER 16 Wet Areas
Stone Toilet Partitions
Floor-Supported Partition Details .................................. 16-D-1
Ceiling-Mounted Partition Details ................................. 16-D-2
Floor-Supported Partition Details .................................. 16-D-3
Ceiling-Mounting Details ............................................ 16-D-4
Dowel-Mounted Partition Details .................................. 16-D-5

Page 4 • Table of Contents  2016 Marble Institute of America

Directory of Detail Drawings, continued

CHAPTER 16 Wet Areas (continued)

Stone Urinal Partitions
Floor-Supported Partition Details .................................. 16-D-6
Wall Mounted Details ................................................ 16-D-7
Stone Shower Partitions
Typical Plans ........................................................... 16-D-8
Typical Elevations ..................................................... 16-D-9
Typical Details ......................................................... 16-D-10
Typical Details ......................................................... 16-D-11
Typical Details ......................................................... 16-D-12
Typical Details ......................................................... 16-D-13
Typical Details ......................................................... 16-D-14
Stone Shower Ceilings
Typical Details ......................................................... 16-D-15
Stone Shower Accessory Niche
Typical Details ......................................................... 16-D-16
Stone Shower Partitions
Typical Floor Details .................................................. 16-D-17
Typical Door Jambs ................................................... 16-D-18
Typical Wall Penetrations ........................................... 16-D-19
CHAPTER 17 Counter and Lavatory Tops
Typical Kitchen Layout, Joints at Sink ............................. 17-D-1
Typical Kitchen Layout, Joints at Corners in Lieu of Sink ..... 17-D-2
Corner Joinery Examples ............................................ 17-D-3
Typical Joinery at Kitchen Sink ..................................... 17-D-4
Rodding Reinforcement .............................................. 17-D-5
Typical Countertop Support......................................... 17-D-6
Recommended Countertop Overhang ............................ 17-D-7
Undermount Sink Support ........................................... 17-D-8
Support Details for Heavy (Enameled Cast-Iron) Sinks ........ 17-D-9
Support Details for Rimmed or “Drop-in” Sink Types.......... 17-D-10
Vanity Top Details .................................................... 17-D-11
Backsplash Details ..................................................... 17-D-12
Options at Sidesplash ................................................. 17-D-13
Stone Shelf Details..................................................... 17-D-14
Countertop Overhang Details ....................................... 17-D-15
Edge Profile Nomenclature .......................................... 17-D-16
Example Shop Drawing .............................................. 17-D-17
CHAPTER 18 Coping and Stools
Exterior Cubic Stone Coping and Walls
Flashing and Coping Details ......................................... 18-D-1
Thin Stone Stools and Cubic Sills
Window Stool Details ................................................ 18-D-2

 2016 Marble Institute of America Table of Contents • Page 5

Directory of Detail Drawings, continued

CHAPTER 19 Stone Furniture

Conference Table Top Details ...................................... 19-D-1,-2
Edge Profile Nomenclature .......................................... 19-D-3
CHAPTER 20 Stone-Faced Veneer Precast Concrete Panels
Typical Detail .......................................................... 20-D-1,-2
CHAPTER 22 Tolerances in the Dimension Stone Industry
Graphic Interpretation of Tolerances .............................. 22-D-1

Page 6 • Table of Contents  2016 Marble Institute of America

FOREWORD
How did man discover the beauty hidden in
stone? The curiosity of an unknown genius may
have been sparked by markings on exposed
ledges. Smoothing the surface and cleaning the
stone to get a closer look may have revealed THE MIA+BSI
color, veins, and graining. Rubbing the stone
with sand may have polished it. To work with In 2016, the memberships of the Marble Institute
of America (MIA) and the Building Stone
stone is to work with the basic rhythms of the
Earth. Institute (BSI) entered into 2-year joint venture
to operate as a consolidated organization.
By the time the pyramids were built, man had
become highly skilled in the use of stone to shape Together, MIA and BSI serve more than 1900
and place it according to his needs. Many of the members in 55 countries who represent every
stone works of ancient man have survived with aspect of the natural stone industry, offering
little visible sign of change, except for them a wide array of technical and training
earthquakes, wars, natural disasters, and more resources, professional development, regulatory
recently, the pollution of civilization. advocacy, and networking events.

The need for building materials in which beauty During the 2-year joint venture (2016-17), each
and permanence are prerequisites is greater organization will maintain its individual identity
today than ever before. To meet this increasing but will be working together to incorporate a
need, the dimension stone industry, through its number of BSI technical papers/topics into the
international trade association, the Marble next DSDM version (9.0).
Institute of America, provides products that
satisfy contemporary design concepts while HISTORY - THE MARBLE
retaining all the outstanding qualities for which
the industry has always been respected. INSTITUTE OF AMERICA
MIA traces its roots back to the National
Dimension Stone Design Manual Association of Marble Dealers, founded in 1907,
Copyright  2016, 2011, 2007, 2003, 1999, which joined with the National Association of
1991, 1985, 1983, 1976 (revised), 1971 by the Marble Producers in 1944 to form the Marble
Marble Institute of America, Inc. Institute of America (MIA). The National
All rights reserved. Association of Marble Builders merged with MIA
Printed in the United States of America. in 1962.

Marble Institute of America, Inc. HISTORY - THE

380 East Lorain Street
Oberlin, Ohio 44074 U.S.A. BUILDING STONE
www.marble-institute.com INSTITUTE
Email: miainfo@marble-institute.com
BSI traces its roots back to 1919 and has
PH: 440.250.9222; fax 440.774.9222
undergone several name changes. The National
Cut Stone Contractor’s Association was changed
to The International Cut Stone Contractors and
Quarrymen’s Association in 1952 and then in
1955 became the Building Stone Institute.

 2016 Marble Institute of America i

DIMENSION STONE
DESIGN MANUAL

The purpose of the Dimension Stone Design Manual

is to present reliable performance data and
design information in one volume in order to
facilitate use of dimension stone in architectural
designs. The dimension stone industry provides
quality products that meet the design and
construction requirements of the buildings of
today, as well as tomorrow.

The Dimension Stone Design Manual presents

current practice in the industry. The information
also represents industry recommendations and
experience published in previous forms as the
former American Standard Specifications for Interior
and Exterior Marble, the Marble Engineering
Handbook, and Dimension Stone Design Manual I, I-
R, II, III, IV, V, VI, VII (these publications are out
of print). Some detail plates from older MIA
publications are reproduced because they still
illustrate current practice.

ACKNOWLEDGEMENTS
The MIA was able to compile the information in
this edition only with the willing cooperation and
assistance of many Members, Committees of
Members, editors, other individuals and
organizations, and MIA staff. We are grateful for
their combined commitment to the MIA and the
dimension stone industry.

ii  2016 Marble Institute of America

LIMITATIONS ON USE necessarily result in failure, nor does adherence
to these practices necessarily result in success.
AND DISCLAIMER Thorough review of project details should be
completed by a competent industry professional
As with any building material and technique: prior to construction. The methods prescribed
herein do not supersede those in applicable
1. Many variations, including but not limited construction specifications and building codes.
to design, climate, topography, building and No warranty or guarantee is made by MIA.
zoning codes, materials, labor cost, and quality,
markedly affect the safety, cost, utility, and
appearance of the applications shown in this
Manual. Accordingly, the variations contained in
the Manual are not being recommended or
endorsed by the MIA.

2. Nothing in this Manual should be used

without independent approval by a qualified
architect, professional engineer, contractor, or
other technically qualified person who should
also specify dimension stone and installation
methods and systems, with specific location of
expansion and control joints on drawings, and
use of standards, such as those of the American
National Standards Institute (ANSI) and ASTM
International, to develop specifications.

3. ACCORDINGLY, THE MARBLE INSTI-

TUTE OF AMERICA DISCLAIMS ANY
GUARANTEE OR WARRANTY, WHETHER
EXPRESS OR IMPLIED, FOR MERCHANT-
ABILITY, FITNESS FOR A PARTICULAR
PURPOSE, OR ANY OTHER PURPOSE, OR
FOR SAFETY FOR ANYTHING DESCRIBED
OR ILLUSTRATED HEREIN, AND ASSUMES
NO RESPONSIBILITY FOR ERRORS AND
OMISSIONS.

4. References to ANSI or ASTM standards are

merely suggested and are not mandatory and are
NOT an MIA express or implied endorsement or
warranty of the adequacy or completeness of
those standards for safety or any other purpose.

This manual represents general practices found

to be successful in natural stone applications.
Regional practices may vary from those
described in this manual. Given the variable
involved in working with natural stone products,
deviation from these practices does not

 2016 Marble Institute of America iii

ORGANIZATION
WEBSITES International Masonry Institute (IMI)
www.imiweb.org
American Concrete Institute (ACI)
www.concrete.org Marble Institute of America, Inc. (MIA)
www.marble-institute.com
American Geosciences Institute (AGI)
www.agi-usa.org Masonry Institute of America (MIA)
www.masonryinstitute.org
American Institute of Architects (AIA)
www.aia.org National Association of Architectural
Metal Manufacturers (NAAMM)
American National Standards Institute www.naamm.org
(ANSI)
www.ansi.org National Building Granite Quarries
Association, Inc. (NBGQA)
American Society of Civil Engineers www.nbgqa.com
(ASCE)
www.asce.org National Tile Contractors Association
(NTCA)
American Institute of Steel Construction www.tile-assn.com
(AISC)
www.aisc.org Natural Stone Council
www.genuinestone.com
American Iron and Steel Institute (AISI)
www.steel.org NSF International
www.nsf.org
APA The Engineered Wood Association
www.apawood.org Precast/Prestressed Concrete Institute
(PCI)
Association of Marble Producers from www.pci.org
Verona
www.asmave.it The International Stone Event
(StonExpo)
ASTM International www.tisewest.com
www.astm.org
Terrazzo Tile and Marble Association of
Building Stone Institute (BSI) Canada
www.buildingstoneinstitute.org www.ttmac.com
Construction Specifications Institute Tile Council of North America (TCNA)
(CSI) www.tcnatile.com
www.csinet.org
United States Green Build Council
European Commission for (USGBC)
Standardization (CEN) www.usgbc.org
www.cenorm.be
Indiana Limestone Institute of America,
Inc. (ILI)
www.iliai.com

iv  2016 Marble Institute of America

Green Building would change inner-city building construction
dramatically. The invention of air conditioning,
reflective glass, and structural steel popularized
Introduction - History of Green the enclosed glass and steel buildings that
Building dominate the American city today. These
buildings were able to be heated and cooled with
History of Green Building – Historical massive HVAC systems that consumed huge
Buildings amounts of cheap and readily available fossil
fuels.4 The massive consumption of energy
Green building is defined by the Office of the required to inhabit these buildings made their
Federal Environmental Executive as “the viability tenable and entirely dependent upon
practice of: 1) increasing the efficiency with energy availability and cost.
which buildings and their sites use energy,
water, and materials, and 2) reducing building
impacts on human health and the environment, History of Green Building – The Infancy
through better siting, design, construction,
operation, maintenance, and removal Around the time that the “glass box” style high
throughout the complete life cycle.” While the
1 rise had become the icon of the American city
green building movement has gained momentum (circa 1970), a forward-thinking group of
in the last decade, the origin can be traced back architects, environmentalists, and ecologists5
to the late nineteenth century. were inspired by the growing environmental
movement and the higher fuel costs that were
According to David Gissen, curator of prevalent during the 1970s.6 The genesis of
architecture and design for the National Building these two scenarios ultimately resulted in the
Museum in Washington, DC, structures such as modern green building movement.
London’s Crystal Palace and Milan’s Galleria
Vittorio Emanuele II used methods that The first Earth Day, celebrated in April 1970,
decreased the impact of the structure on the gave some credence to this new building
environment. Systems such as roof ventilators concept, but the OPEC oil embargo of 1973
and underground air-cooling chambers were gave the burgeoning environmental movement,
used to regulate indoor air temperature.2 In the and subsequently the green building effort the
early twentieth century, several skyscrapers, kick start it needed. With gas lines stretching for
such as the Flatiron Building and the New York blocks, some Americans began to question the
Times Building in New York, utilized deep-set conventional wisdom of being so reliant upon
windows and the Carson Pirie Scott department fossil fuels for our energy.7
store in Chicago had retractable awnings. Both As a result of the oil embargo, among other
of these techniques were effective in controlling energy concerns, the American Institute of
interior temperature while lessening the Architects (AIA) formed a Committee on Energy
buildings’ impact on the environment.3 that was broken into two camps. “One group
From the 1930s through the 1960s, the forward- looked toward passive, such as reflective roofing
thinking cooling methods mentioned above gave materials and environmentally beneficial siting of
way to some new building technologies that buildings, to achieve energy savings, while the

1 Office of the Federal Environmental Executive, “The 4 Building Design and Construction, “White Paper on
Federal Commitment to Green Building: Experiences Sustainability”, page 4, November 2006
and Expectations,” 18 September 2003. 5 Building Design and Construction, “White Paper on
2 Building Design and Construction, “White Paper on Sustainability”, page 4, November 2006
Sustainability”, page 4, November 2006 6http://www.nyc.gov/html/nycwasteless/html/in_busi
3 Building Design and Construction, “White Paper on ness/green_building.shtml
Sustainability”, page 4, November 2006 7Building Design and Construction, “White Paper on

Sustainability”, page 4, November 2006

 2016 Marble Institute of America v
other concentrated more on technological plan to make the White House the “model for
solutions, such as the use of triple-glazed efficiency and waste reduction.”12
windows.”8 The “Greening of the White House” program
As energy concerns subsided, momentum for was designed to improve “energy efficiency and
green building and the environment, in general, environmental performance of the White House
slowed down, but a dedicated core group of complex by identifying opportunities to reduce
architects continued to push their green building waste, lower energy use, and make an
concept forward. A couple of notable buildings appropriate use of renewable resources, all while
constructed during the 1970s that utilized improving the indoor air quality and building
concepts of green design are: The Willis Faber comfort.”13 In March 1996, it was reported that
and Dumas Headquarters in England, which through the first two years of the “Greening”
utilized a grass roof, day-lighted atrium, and project, more than $150,000 per year in energy
mirrored windows, and the Gregory Bateson and water costs, landscaping expenses, and
Building in California, which used energy- expenditures associated with solid waste were
sensitive photovoltaic (solar cells)9, under-floor saved. Since 1996, $300,000 has been saved
rock-store cooling systems, and area climate- annually due to additional projects. In all, 845
control devices.10 metric tons per year of carbon emissions were
eliminated during Clinton’s presidency.14
Through the late 1970s, throughout the 1980s,
and into the early 1990s, much research was Some of the methods utilized to “green” the
commissioned on energy efficient processes. White House were as follows:
This research resulted in more effective solar 1. Building Envelope – decreasing energy lost
panels, pre-fabricated efficient wall systems, through the roof, windows, walls, etc.
water-reclamation systems, modular
construction units, and direct usage of light 2. Lighting – utilizing energy-saving light bulbs
through windows in order to decrease daytime and maximizing use of natural light.
energy consumption.11 3. Plug Loads – Energy-saving office
equipment was installed. Refrigerators and
History of Green Building – The Greening coolers were replaced with more energy-
of the White House efficient models.
When Bill Clinton was elected President in 4. Waste – a comprehensive recycling program
1992, the green build/sustainability was initiated.
communities began to toss around the idea of 5. Vehicles – leased many vehicles that utilized
“Greening the White House” as a way to put their cleaner-burning fuels.
ideas on the radar screens of everyday American
society. Twenty-three years after the initial 6. Landscaping – reducing unnecessary water
Earth Day, President Bill Clinton announced a and pesticide usage.15

8Building Design and Construction, “White Paper on 13“The Greening of the White House”,
Sustainability”, page 4, November 2006 http://clinton3.nara.gov/Initiatives/Climate/greenings
9“Photovoltaic Fundamentals”, ummary.html
www.fsec.ucf.edu/pvt/pvbasics 14The Greening of the White House”,
10Building Design and Construction, “White Paper on http://clinton3.nara.gov/Initiatives/Climate/greenings
Sustainability”, page 4, November 2006 ummary.html
11 Building Design and Construction, “White Paper on 15The Greening of the White House”,

Sustainability”, page 4, November 2006 http://clinton3.nara.gov/Initiatives/Climate/greenings

12Building Design and Construction, “White Paper on ummary.html
Sustainability”, page 5, November 2006
vi  2016 Marble Institute of America
History of Green Building – Where Are Energy and Environmental Design (LEED), the
We Now? program with which points are awarded to
various design applications within a building
With the overwhelming success of the “Greening
ultimately resulting in LEED certification for the
of the White House”, other government
building.
institutions have since been given a green
makeover. The Pentagon, the Presidio, and the
U.S. Department of Energy, among others, have
gone green.16 USGBC (The United States Green
Build Council) & LEED
The concepts of green building and, on a larger
(Leadership in Energy and
scale, sustainability are ideas that we hear all of
the time. These two concepts, however, are Environmental Design)
rarely properly understood. USGBC
“Sustainability is a systemic concept, relating to The USGBC was created to promote the design
the continuity of economic, social, institutional and construction of buildings that are
and environmental aspects of human society, as environmentally responsible, profitable, and
well as the non-human environment. It is healthy places to live and work. They are
intended to be a means of configuring civilization focused on integrating building industry sectors
and human activity so that society, its members and leading a market transformation towards
and its economies are able to meet their needs greener construction. The organization consists
and express their greatest potential in the of various trade associations, architects,
present, while preserving biodiversity and designers, and individuals all interested in the
natural ecosystems, and planning and acting for greening of the construction business.18
the ability to maintain these ideals for a very long
Between 1990 and 1995, the USGBC worked
time. Sustainability affects every level of
feverishly with the American Society of Testing
organization, from the local neighborhood to the
and Materials in order to create a rating system
entire planet”.17 In short, the concept of
for sustainability. ASTM’s rigorous consensus-
sustainability refers to thinking holistically about
based process moved much too slowly for the
how everything you do affects everything around
USGBC, and in 1995, it was determined that
you. It is an attempt to minimize each person’s
they would create their own rating system to
impact on the world.
exist under the USGBC banner. A committee
Today, green building is one of the fastest was formed to study other green building
growing building and design concepts. Every programs currently in existence, and after three
month, new magazines are popping up that years, LEED 1.0 unveiled.19 By 2003, LEED was
report on this growing trend. Architects, refined to its current form that is the talk of the
designers, and homeowners are becoming construction and design communities.
infatuated with the cost-saving possibilities,
energy-saving emphasis, modern look, and the
symbiotic relationship with nature that green LEED
buildings possess. In short, LEED is a system for designing,
The United States Green Build Council constructing, and certifying green buildings.
(USGBC) is the foremost leader and educator Buildings are classified as Certified, Silver, Gold,
within the world of green building today. They or Platinum, depending upon the number of
are the sanctioning body for Leadership in

16Building Design and Construction, “White Paper on 18“An Introduction to the USGBC and LEED Green
Sustainability”, page 5, November 2006 Building Rating System”, www.usgbc.org
17 http://en.wikipedia.org/wiki/Sustainability 19Building Design and Construction, “White Paper on

Sustainability”, page 7, November 2006

 2016 Marble Institute of America vii
points they acquire within six building  Support the regional economy by using
components20: materials and products manufactured
1. Sustainable Sites regionally.
2. Water Efficiency  Encourage environmentally responsible
forestry through the use of wood or wood-
3. Energy and Atmosphere
based material that meets Forest
4. Materials and Resources Stewardship Council’s Principles and
5. Indoor Environmental Quality Criteria for wood building components.

6. Innovation and Design Process  Utilize rapidly renewable materials, such as

bamboo flooring, wool carpets, strawboard,
Within each of these categories, there are a cotton ball insulation (made from denim
specific number of credits available via many scrap), genuine linoleum flooring, or poplar
subcategories. LEED ratings are rapidly oriented-strand board (OSB). Using rapid
becoming boasting points for property owners, renewables helps reduce the use and
with property values of LEED-certified buildings depletion of finite raw materials.
skyrocketing.
Construction and Demolition Waste
LEED has been assisted in its success by the early Management
adoption of many government agencies. Today,
however, it is mostly a market-driven engine,  Develop and implement a waste
with the number of LEED registered projects management plan that diverts a substantial
growing each year. amount of construction, demolition, and
land-clearing debris from landfills to
recycling or salvage facilities.
Characteristics of LEED Building  Reuse a percentage of salvage or refurbished
Site Design and Planning materials from construction, demolition, or
land clearing as new building material. For
 Site a building within proximity of more information on the benefits of
commuter rail or bus lines to reduce salvaging materials from existing sites, go to
pollution and any land-development impacts www.deconstruction.com.
associated with increased automobile usage.
Energy and Atmosphere
 Establish building specifications that
maintain the current level of storm-water  Generate building electricity on site from
runoff or decrease the amount of renewable resources like geothermal, solar,
imperviousness already existing on site. or biogas sources.
 Develop a site with a minimum density of  Eliminate the use of chlorofluorocarbons
60,000 square feet per acre. Channeling (CFCs) in new heating, ventilation, air-
development to urban areas with existing conditioning, and refrigeration (HVAC & R)
infrastructure protects green spaces and systems. Eliminating the use of CFCs
preserves natural habitats and resources. reduces ozone depletion.
Material and Product Selection  Contract with a green power provider to
purchase building electricity generated from
 Use building materials and products that renewable resources, such as solar, wind,
contain post-consumer recycled content.

Building Design and Construction, “White Paper on

20

Sustainability”, page 7, November 2006

viii  2016 Marble Institute of America
 geothermal, biomass, or low-impact hydro Stone in Green Building
sources.
What is Stone’s Current Perception?
 Optimize energy performance. With the growing influence of green building, it
Water Management is imperative that the natural stone industry does
everything it can to position its product as being
 Install water-efficient or low-flow green friendly. Despite what many of us in the
equipment and appliances in kitchens and industry may think (natural stone is about as
bathrooms to reduce water consumption. green as something can get), that perception is at
 Use water-efficient irrigation, captured rain, odds with the prevailing thought among the
or site-recycled water for onsite architecture and design communities. Many of
landscaping. these misconceptions arise from the inaccurate
idea that mining natural stone is somehow on par
 Utilize innovative wastewater technologies, with strip mining, an environmentally
such as treating wastewater on site or devastating practice.
significantly decreasing the amount of
potable water used for sewage conveyance. One facet of LEED certification in which natural
stone stands out is in product origin. A major
Indoor Environment tenet within the green community is that of
 Design the HVAC system and building supporting local products and business. LEED
envelope to provide for the optimal delivery points are available for products whose origin or
and mixing of fresh air. Effective air manufacturing is within 500 miles of the building
exchange supports the safety, comfort, and site. Regionally manufactured and extracted
well-being of building occupants. materials reduce environmental impact by
lowering emission of greenhouse gases during
 Reduce the number of indoor air transportation while supporting local
contaminants by selecting paints and economies. Fortunately for the stone industry,
coatings, adhesives, carpets, and composite there is a quarry site within 500 miles of nearly
woods that emit low Volatile Organic everywhere in the United States and Canada.
Compounds (VOCs) or none at all.
Future Areas of Emphasis
Examples of low-VOC emitting products
are carpets made of wool, carpets made of There are some areas where natural stone should
recycled plastic bottles, and low-VOC paint. be an obvious choice for green builders, but
where further research is needed to prove the
 Establish segregated areas for chemical-using hypothesis:
operations (such as copy/printing rooms and
housekeeping); these areas should have  The enduring life cycle of natural stone
separate outside exhaust and no air makes it a great green build option. Because
recirculation. stone has proven that over the centuries it
holds up to weathering and time better than
 Maximize day lighting and view any other building material, one would think
opportunities. Day lighting and increased that less energy would be consumed by the
view opportunities can save energy costs and initial fabrication and installation than in
enhance worker productivity. 21 manufacturing and replacing another
product.
 The ease of care and maintenance involved
with maintaining natural stone applications

21http://www.nyc.gov/html/nycwasteless/html/in_bus
iness/green_building.shtml
 2016 Marble Institute of America ix
 should be very attractive to those in the The Committee of Sustainability
green community. Harsh chemicals are not In order to properly position natural stone, to
needed to either clean or finish stone. research elements of building with natural stone
 The recyclability of natural stone is that would qualify for LEED points, and to
unequaled. Nearly 100% of stone from old market the use of natural stone as a green
projects and scrap stone are recyclable. product, the Natural Stone Council has
commissioned a Committee on Sustainability.
These components of natural stone use need to The NSC Committee on Sustainability (MIA is a
be studied and reported on adequately before the member) will take the lead for the industry in
natural stone industry can go to the USGBC and ensuring that stone becomes a viable green
request LEED certification points. building option. A couple of early initiatives for
Quarrying the committee are establishing a set of green best
practices for quarrying and fabrication. The
In the past 15 to 20 years, the business of
committee is also pursuing the commissioning of
quarrying has been vastly cleaned up from an
studies to research Life Cycle Assessment, Life
environmental perspective. Domestic quarries
Cycle Cost, Water Use Reduction, Construction
today are required to comply with a strict code
Waste Management, and Material Reuse for the
of practice and are monitored by OSHA, U.S.
Natural Stone Industry. While the initiatives
Department of the Interior, EPA, the
being undertaken by the Committee on
Department of Resources and Economic
Sustainability are aggressive, they are greatly
Development, and the Mine Safety and Health
needed in order to ensure that stone becomes a
Administration, among others. This message
viable option for green building.
needs to be spread throughout the entire
construction industry: Quarrying is not what it
was 20 years ago, and certainly not what it was
50 or 100 years ago.
Quarry reclamation projects have added to the
ability of quarries to limit their long-term impact
on the environment. Today, many old quarries
are being turned into golf courses, lakes,
recreation areas, and state parks. A list of quarry
reclamation projects appears at the end of this
chapter as examples of how old quarry sites can
be successfully utilized for the public good.
As technology moves forward, the greening of
quarrying will continue and this will, in turn,
continue to further enhance natural stone’s
position within the green community.

x  2016 Marble Institute of America

Additional GREEN References Canoe Creek State Park
Quarry Reclamation Site List Hollidaysburg, PA
www.dcnr.state.pa.us/STATEPARKS/PARKS
Quarry Park and Nature Preserve /canoecreek.aspx#history
County of Stearns, MN
www.co.stearns.mn.us/1450.htm Banning State Park
Sandstone, MN
Halibut Point State Park www.dnr.state.mn.us/state_parks/banning/in
Gloucester, MA dex.html
www.mass.gov/dcr/parks/northeast/halb.htm
Sleeping Giant State Park
The Quarry Golf Club Hamden, CT
San Antonio, TX www.sgpa.org/
www.quarrygolf.com/
Knightdale Environmental Education
Oak Quarry Golf Club Park
Riverside, CA Knightdale, NC
www.oakquarry.com/ www.hsmm.com/UPLOADS/BD/News/200
50427_013046/Art_Knightdale_Lnd%20Wtr_
Crystal Springs Quarry Golf Club 10%2004%20(final).pdf
Maryland Heights, MO
crystalspringsquarry.com/ Emerald Lake State Park
East Dorset, VT
Old Quarry Nature Center www.vtstateparks.com/htm/emerhist.cfm
Danbury, CT
www.danbury.org/oldquarry/

Quarry Lakes Regional Recreational Area

Fremont, CA
www.ebparks.org/parks/quarry.htm

Quarry Oaks Golf Club

Ashland, NE
www.quarryoaks.com/

Bomoseen State Park

Fair Haven, VT
www.vtstateparks.com/htm/bomoseen.cfm

Natural Bridge State Park

North Adams, MA
www.mass.gov/dcr/parks/western/nbdg.htm

Elephant Rocks State Park

Belleview, MO
www.mostateparks.com/elephantrock.htm

 2016 Marble Institute of America xi

 b) No attempted alteration or repair of
Suggested Contract the dimension stone or its installation
Warranty Provision/ has been made without Company’s
written consent;
Disclaimer c) The dimension stone is inspected by
Owner or representative on arrival at
The following warranty is provided as a guide only to
the project site for visible defects, and
Marble Institute of America Members who desire to
complaints relating thereto are filed in
or are required to provide warranties in connection
writing immediately with Company
with contracts with their customers (“Owner”).
before installation; and
However, the Member is cautioned that such
d) The dimension stone or installation
language and the legal obligations arising therefrom
thereof is not subjected to misuse,
must be reviewed and approved by the individual
negligence, accident, or use contrary to
Member’s legal counsel prior to usage on a case-by-
Company’s written instructions.
case basis. MIA is not providing legal advice to
Members, nor may a Member rely on these 3. Company does not warranty dimension stone
provisions as being in compliance with relevant or its installation to any safety, building, or
federal, state or local statutes, ordinances or codes. other code of any state, municipality or other
jurisdiction unless the terms of such code are
W a r ra nty specifically incorporated into Company’s
1. [Name of Company] (“Company”) warrants to written contract with Owner. Except for this
the Owner on project in which Company warranty by Company, Owner assumes all risk
installs dimension stone for one year from the and liability for the use of such dimension stone,
date of the completion of installation, that the whether alone or in combination with other
dimension stone shall be free from defects in building materials.
material and workmanship IF, BUT ONLY IF:
a) The dimension stone, its specifi- 4. THIS WARRANTY IS EXPRESSLY IN LIEU
cations, and installation are set forth in OF ALL OTHER WARRANTIES, EXPRESS
a written contract signed by Company OR IMPLIED, INCLUDING ANY IMPLIED
and Owner; WARRANTY OF MERCHANTABILITY OR
b) The Owner does not hinder Company FITNESS FOR A PARTICULAR PURPOSE.
from installing dimension stone and COMPANY SHALL NOT BE LIABLE UNDER
other materials and performing THIS WARRANTY FOR ANY OTHER LOSS
services in conformity with the OR DAMAGE INCLUDING WITHOUT
contract; and LIMITATION, CONSEQUENTIAL
c) Such dimension stone installation was DAMAGE, SAFETY PROBLEMS, OR
not exposed to conditions more severe PERSONAL INJURY RESULTING
or otherwise exceeding those set forth DIRECTLY OR INDIRECTLY FROM THE
in the contract specification. PURCHASE, OTHER ACQUISITION, USE,
OR LOSS OF THE DIMENSION STONE,
2. Company’s obligation under this warranty is EXCEPT AS EXPRESSLY SET FORTH
limited to replacing or repairing, free of charge, HEREIN.
F.O.B. point of fabrication, any defective
dimensional stone, IF, BUT ONLY IF: 5. No statement by Company’s employee or agent
a) Owner notifies Company by certified directly or indirectly admitting liability under
mail, return receipt requested, of such this warranty shall be binding against Company
breach of warranty, within ninety (90) unless: a) made in writing; b) made by a
days after the discovery thereof, representative of Company authorized to do so.
otherwise such claim is waived.
(However, without limitation on the
foregoing, any alleged defect
discovered more than one year after
installation is excluded from warranty.)

xii  2016 Marble Institute of America

 4. Sample approval. Fabrication of stone will
Suggested not commence until the Purchaser has approved
Residential in writing below the stone samples or slabs to
be furnished by the Seller. Seller shall not be
Contract bound by samples furnished by the Purchaser
(Installation of (from third parties) unless indicated below:
Dimension Stone) □ Samples provided by Seller, approved by
Purchaser. ____ (Purchaser’s Initials)
The following residential contract is provided as a
□ Seller acknowledges review of Purchaser’s
guide only to Marble Institute of America Members. samples and acceptance. ____ (Seller’s Initials)
However, the Member is cautioned that such
language and the legal obligations arising therefrom 5. Commencement; Completion. The work
must be reviewed and approved by the individual shall commence on or about __________ and
Member’s legal counsel prior to usage on a case-by- will be completed on or about __________,
case basis. MIA is not providing legal advice to provided, however, Seller shall not be
Members, nor may a Member rely on these responsible for delays in commencement or
provisions as being in compliance with relevant completion caused by events beyond the
federal, state or local statutes, ordinances, or codes Seller’s reasonable control.
(for example, Home Sales Solicitation Act in Ohio).
6. Ownership of work. No legal interest in the
R e s id e ntia l C ontr a ct stone work shall pass to Purchaser until full
price has been paid, regardless of the location of
This RESIDENTIAL CONTRACT to provide and the stone work, and whether it has been
install dimension stone, entered into between installed or not installed in the residence.
_____________________ (“Purchaser”) residing
at _____________________ (“Residence”) and 7. Standards and Guidelines. Installation of
_____________________ (“Seller”) with the stone work by the Seller shall be in strict
principal office at _______________, with accordance with the Marble Institute of
effective date of the ___ day of _______, 20__. America’s Dimension Stone Design Manual, as
updated from time to time. No deviation from
1. Services. Subject to the terms and provisions the standards, guidelines, or other work
herein, Seller agrees to provide to Purchaser specifications set forth in said Manual shall be
the following services (check applicable boxes): permitted.
□ Fabricating and installing kitchen countertops
□ Supplying and installing stone paving 8. Assignment. This agreement is personal to
□ Supplying and installing stone bath work the parties and may not be assigned without the
□ Supplying and installing other stone work: written consent of the nonassigned party.
PURCHASER: ________________________
_________________________________ Print Name: ________________________
(describe)
Date Signed: ________________________
2. Contract price. The total contract price, as PURCHASER: ________________________
installed, is $__________________. Print Name: ________________________
Date Signed: ________________________
3. Schedule of payments. The contract price
SELLER: ________________________
shall be paid as follows:
Print Name: ________________________
A. $______ on signing this contract.
B. $______ on completion of field Date Signed: ________________________
measuring.
C. $______ on commencement of
fabrication.
D. $______ on completion of fabrication.
E. $______ on completion of installation.

 2016 Marble Institute of America xiii

MIA CODE OF ETHICS homeowners) before, during, and after
installation.

Members of the Marble Institute of America, upon  We shall strive to promote a spirit of
acceptance as Members in good standing, agree to cooperation within the industry.
abide by the following Code of Ethics:
We assume these responsibilities freely and
Members of the Marble Institute of America believe solemnly, mindful that they are continuing
and affirm that: conditions to and part of our obligation as
Members of the Marble Institute of America.
The fabrication and installation of dimension-cut
natural stone should meet MIA and other
industry standards as articulated in the MIA
Dimension Stone Design Manual and other technical
publications, along with courteous and NOTE: A copy of the MIA Code of Ethics is
professional customer service. To achieve these presented to each Member upon acceptance into
goals, we pledge adherence to the following membership. The document is suitable for
principles and policies: framing and display in the Member’s office or
showroom.
 Our primary objective is a satisfied and
happy customer, be it a homeowner, a
building owner, or a design professional.

 We will maintain and conduct business in

accordance with fair and honorable
standards of competition.

 Honesty, integrity, quality, and

professionalism guide our firm’s business
philosophy.

 High standards of health, safety, and product

quality will be incorporated into every
installation.

 We shall deal fairly with customers, as well

as with our employees, our subcontractors,
and our suppliers.

 We encourage research to develop new

materials, techniques, tools, and equipment,
as well as improved methods of stone
fabrication and installation.

 We pledge to assist in the education and

product knowledge of our firm’s clients and
customers (builders, kitchen and bath
dealers, architects, designers, and

xiv  2016 Marble Institute of America

MIA Membership advantages of natural stone to increase demand
within the commercial and consumer markets.
Membership in the Marble Institute of America MIA Receivables Management Solutions
provides you with outstanding advocacy, MIA Members can receive a variety of customized
networking, marketing & publicity, information outsourcing services to meet their collection needs
& education, and professionalism and stone from VeriCore. Preferred rates are offered on all
craftsmanship — benefits that continue to make collection accounts, outsourcing, complimentary
MIA one of the fastest-growing trade associations demand letters and many other services to help
in the world. Members are also encouraged to take improve your bottom-line.
advantage of a whole array of value-added services
that can easily pay for your membership costs and The Cutting Edge Newsletter
add money to your bottom line. This monthly newsletter provides valuable
industry and association news, new member
With MIA and its member-friendly, cost-saving listings, member activity updates, and Technical
services you can save money on collections, Q&A column.
credit card transactions, office supplies, lead
referrals, shipping, and utility costs. MIA Membership Directory
Print and online versions of the directory give you
MIA Member Benefits Include: quick access to fellow producers/quarriers,
fabricators, installers, distributors, and
MIA Freight Discount Program contractors with whom you can do business.
Save money on your shipping costs by using the
services of FedEx®, YRC, and UPS Freight. Discounted StonExpo Registration
MIA Regular Members receive reduced-rate
MIA Credit Card Processing Program admission to StonExpo, the premier trade show of
MIA members in the U.S. receive tremendous the natural stone industry, held concurrently with
savings on Visa, MasterCard, & debit card the MIA Annual Meeting.
processing. Online account management, 24
hour a day customer service, plus exclusive Office Supplies and Print Services Program
discounts on point of sale solutions and The MIA and OfficeMax introduce the new
additional products and services are all accessible OfficeMax Partner AdvantageSM program. This
with no monthly minimum fee. members-only program will allow you to take
Free Technical Guidance advantage of special promotions and other one-of-
MIA serves as the industry’s leading clearinghouse a-kind benefits.
of information about natural stone and can Internet Exposure
respond to technical and other questions from MIA operates a web site that can drive new
Members as well as those in the construction, business your way: www.marble-institute.com is
architectural, and design communities. designed for natural stone professionals, architects
Consultation on specific questions is also available and members of the design community. Direct
at no charge to Members from MIA’s Technical links to your web site draw interested parties to
Director. your business.
MIA Bookstore Discounts And more! For a complete listing of MIA
MIA Members save up to 50% on technical member benefits, go to www.marble-
publications and consumer brochures. institute.com or call the Membership Department
Industry Promotion at 440.250.9222.
MIA actively works to educate design
professionals, homeowners, and others about the

 2016 Marble Institute of America xv

NOTES:

xvi  2016 Marble Institute of America

 MARBLE INSTITUTE OF AMERICA (MIA)
SAMPLE SPECIFICATION LANGUAGE FOR DESIGN
PROFESSIONALS

Marble Institute of America (MIA)

For over 70 years the Marble Institute of America (MIA) has been the world's leading
information resource and advocate for the natural stone industry.

 MIA members include marble, granite, limestone, sandstone and other natural stone
producers and quarries, fabricators, installers, distributors and contractors around the
world. MIA Members, upon acceptance as members in good standing, agree to abide by
a Code of Ethics.

Sample Language for Fabricator/Installer Qualifications (Residential or

Commercial Projects)
Fabricator/Installer Qualifications: A Marble Institute of America (MIA)
member firm experienced in fabrication/installation of dimension stone as indicated
for this project and whose work has a record of successful in-service performance.

 The Dimension Stone Design Manual (DSDM) is the stone industry's single-source
reference for dimensional stone design and construction facts and details. Contents
include sections on granite, marble, limestone, serpentine, soapstone, travertine,
quartz-based stone and slate with product descriptions and technical data; general
installation guidelines; guidelines and typical detailing for horizontal surfaces, vertical
surfaces, wet areas, furniture and countertops; maintenance of exterior and interior
stone installations; and a glossary of terms relating to dimension stone.

Sample Language to Reference the MIA’s DSDM

For granite, limestone, marble and onyx, quartz-based, serpentine, slate, soapstone,
and travertine, comply with recommendations in MIA's Dimension Stone Design
Manual (DSDM), version 8 (©2016).

 MIA Accreditation for natural stone fabricators and commercial contractors

recognizes those companies that meet the industry's highest standards for business
activities, product knowledge, fabrication and installation. To earn MIA Accreditation, a
company must complete an intensive, rigorous process that includes documentation of

 2016 Marble Institute of America Sample Specification Language • xvii

 SAMPLE SPECIFICATION LANGUAGE FOR DESIGN PROFESSIONALS (Continued)

its business and employment practices, letters of recommendation, a written

examination and site visits to the facility and completed jobs.

Sample Language for MIA Accredited Natural Stone Fabricators

(Residential Projects):
Fabricator Qualifications: Preference shall be given to an MIA Accredited Natural
Stone Fabricator. MIA Accredited Natural Stone Fabricators are those companies
that meet the industry's highest standards for business activities, product knowledge,
fabrication and installation. Bidding company must supply their official MIA
Accreditation number as proof of accreditation.

Sample Language for MIA Accredited Commercial Contractors:

Installer Qualifications: A firm experienced in installing engineered dimension stone
cladding systems. Company must be an MIA Accredited Commercial B Contractor
(low rise) or an MIA Accredited Commercial A Contractor (high rise) of current
good standing with the Marble Institute of America. Bidding company must supply
their official MIA Accreditation number as proof of accreditation.
Installer’s responsibilities include sourcing of qualified fabricator of dimension stone
cladding and providing professional engineering services per project requirements.
Engineering Responsibility includes comprehensive design of stone attachment
systems by an experienced, licensed professional in accordance with practices
outlined by the MIA Dimension Stone Design Manual and compliant with applicable
codes. Comprehensive shop drawings with attachment details shall accompany
engineering analysis.

For more information:

Marble Institute of America
380 E. Lorain Street
Oberlin, OH 44074
USA
PH: 440-250-9222
FAX: 440-774-9222
www.marble-institute.com

Sample Specification Language • xviii  2016 Marble Institute of America

The geology of 2.0 STONE CATEGORIES
Stone 2.1 Three general rock or stone categories
are recognized according to their mode of
1.0 INTRODUCTION origin. This is a genetic classification, and it not
only states how and under what general
1.1 Earth is geologically classified as a “stony conditions a stone was formed, but also implies
planet,” as it is entirely stone (rock) of various a general compositional range. The basic stone
mineral compositions and forms, excluding its groups are:
water and atmosphere.
2.1.1 Igneous rock is formed by
1.2 Earth scientists prefer the term “rock,”1 solidification (cooling) or, in some cases, by
while the commercial stone industry, prefers solid-state transformation3 of molten or semi-
the term “stone”.2 Both words are correct in molten material in the Earth’s upper mantle or
their respective frame of reference, and for crust into crystalline rock generally consisting
practical purposes, interchangeable. Every of silicates (compounds with SiO4) and some
type of rock or stone is composed of one or dark-colored accessory minerals such as iron
more minerals. For those who work with oxides or other iron- and magnesium-bearing
dimension stone, it is important to know these silicate minerals. Example: granite.
minerals—there are about 25 common
minerals—that make up the bulk of all 2.1.2 Sedimentary rock can be:
dimension stone commonly used. These 25
minerals are easy to learn to recognize, and this 2.1.2.1 Detrital sedimentary stone,
basic knowledge in turn helps to identify the which is the naturally cemented accumulation
many varieties of natural stone. of solid granular materials or particles derived
from both mechanical and chemical weathering
1.3 Identifying the minerals in a particular of any existing rock. Examples include
type of stone is important because the limestone, shale, sandstone, and
properties and behavior of stone are the sum conglomerate.
total of the properties and behavior of the
minerals found in the stone. Knowing 2.1.2.2 Chemical sedimentary stones,
something about the mode of formation or the precipitates of chemicals like salt that are
“genesis” of a stone further aids predicting the the dissolved weathering products of any
behavior of a stone. Thus, performance existing rocks. Chemical weathering yields
questions can be knowledgeably approached, some soluble salts, and examples of the
such as how a particular stone might behave in resulting stones include onyx (CaCO3),
a given application. Stone industry limestone (CaCO3), dolomite (CaMg(CO3) 2),
professionals need this information to reduce alabaster (CaSO4), some types of travertine
waste and avoid costly mistakes. (CaCO3 + SiO2) and common table salt
(NaCl). Onyx is actually precipitated in
caverns and travertine is a precipitate deposited

1 The Glossary of Geology, 4th edition, 1997, Robert L. 3 A solid-state transformation is an atomic or molecular-
Bates and Julia A. Jackson, eds., American Geological level process by which a compound changes from one
Institute (AGI), defines rock as “a mixture of one or crystalline solid to another new crystalline solid–
more minerals.” without going through an intervening liquid and/or
2 The Glossary of Geology (ibid) defines stone as: “A gaseous state. This process occurs under conditions of
general term for rock that is used in construction, very high pressure, temperature, and chemistry
either crushed for use as aggregate or cut into shaped through time at depths in the crust of several to tens of
blocks as dimension stone.” kilometers.

 2016 Marble Institute of America The Geology of Stone • Page 1-1

around freshwater springs in shallow marine rigid outermost rock layer, which varies from
(salty) water. Alabaster is usually a slightly about 3 to 25 miles thick.
metamorphosed anhydrite or calcium sulfate.
3.2 The underlying mantle is about 1,620
2.1.2.3 Many other chemical precipitates are miles thick and can be is envisioned as two
of no use as dimension stone due to solubility parts: a weak upper mantle of about 190 to
and softness, but may be much more valuable 440 miles of rock, mostly uniform in
as chemical feedstock, table salt, or fertilizer. composition and capable of flow, i.e., not quite
molten. Below it, the lower mantle is a
2.1.3 Metamorphic4 rock is formed denser, “mushy” or partially molten material
from any pre-existing rock type in the Earth’s somewhat different in composition from the
crust under variable conditions of high upper mantle.
pressures, high temperature, chemistry, and
time. The process produces mechanically 3.3 Deep in its center, Earth has a solid,
deformed stone and chemically alters the iron-rich inner core about 760 miles thick,
mineral assemblages of the parent stone. The and a molten metallic outer core about 1,420
new mineral suite may be a different or the miles thick.5 As the inner core is under
same chemical composition as the parent, but tremendous pressure, it is hard to conceive
as newly formed crystals. Examples of what its “molten” physical state is really like.
metamorphic stones include marble, slate,
schist, and gneiss. 3.4 Ocean basins cover approximately 70%
of Earth’s surface and are underlaid by
2.1.3.1 Earth scientists have assigned oceanic-type crust, while a thicker continental-
hundreds of names for rocks in each of the type crust, being lighter in weight, floats on
genetic groups, and for minerals or stones older, denser, oceanic crust. Continents
resulting from different processes of formation comprise the remaining 30% of Earth’s
and slightly different chemical makeup. The surface.
many technical names are confusing; the few
names given in this chapter will suffice for most 3.5 The chart on the following page
commercial purposes. When legal questions contrasts characteristics of the two major kinds
arise, it may be appropriate to consult a of rock in the lithosphere (see next page):
professional earth scientist about stone types
and nomenclature of a particular stone.

3.0 STONE FORMATION

3.1 Igneous Stone (Oceanic and

Continental Stone). The Earth’s crust is
composed of two general types of stone:
oceanic and continental. Each has distinct
characteristics, mineral and chemical
compositions, colors, specific gravities, and
behaviors. Most, but not all, commercial stone
is quarried from continental rock. Earth’s
lithosphere, or rocky crust, is the cool and

4 Metamorphic is a word derived from Greek that 5 Since deep Earth materials cannot be physically
literally means to change in form. examined, the above information is known through
geophysical studies of earthquakes and vibrations from
atomic bomb tests.

Page 1-2 • The Geology of Stone  2016 Marble Institute of America

 Oceanic Stone Continental Si, K, Na, etc., to low Fe, Mg, Ca and high Si,
Stone K and Na.
Dark in color Light in color
Comp: High Iron High silica (SiO2, 3.8 Andesite, named after the Andes
(Fe), Magnesium ≈70%), Potassium Mountains of South America, is a lava stone
(Mg), Calcium (Ca) (K), Sodium (Na) with an intermediate composition at about the
and Aluminum (Al) middle of the element spectrum. It is gray and
Low: SiO2 Low: Fe, Mg, Ca has a medium specific gravity. Andesite flows
(<50%), K, Na & well or poorly depending on its silica content,
Al and may contain all of the following elements
Heavy: Specific Not heavy: Specific in its variable composition: Si, Fe, Mg, Na, Ca,
gravity ≈2.9 Gravity ≈2.6+ K and Al. It is known simply as an
Melting “intermediate” or “Andean-type” stone.
temperatures: High Low: ≈800°+ C.
(1000-1500° C.) 3.9 Plate Tectonics. According to the
Viscosity of Lava: theory of plate tectonics, the lithosphere of the
Very runny – flows Very stiff – Earth is divided into large crustal plates that
like water like honey in winter have continuously separated or collided with
Kind of eruption: each other over millions of years, always
Quiet like Hawaii Explosive like Mt. moving and forming new and destroying old
St. Helens crustal material in the process. Almost all of
Scientific name of the ocean floor is basaltic or volcanic rock
lava type: Basaltic Granitic created by plate movement called “sea-floor
Scientific code spreading,” initiated from mid-oceanic ridges.
word: Mafic6 Felsic7 These linear ridges or rifts are the spreading
centers between undersea crustal plates that
3.6 In each case, it is the elemental content allow molten rock to emerge from the mantle
of the major minerals that make the sharply through volcanic action. Conversely, when
different characteristics shown in the chart. plates collide, the far edge of one oceanic floor
The generalizations of composition in the chart plate is thrust under the edge of the adjacent
hold for most cases. Although the differences plate in a process called subduction. Subducted
in specific gravity or density of the two material is reincorporated into the Earth’s
classifications of stone appear to vary little, that upper mantle.
apparently small difference is enough for
oceanic rock to float on denser layers 3.9.1 The life-span of oceanic floor is typically
underneath. Like blocks of wood in ponds, the no more than 180 million years from formation
world’s continents are floating on heavier, at spreading centers to disappearance of
darker crust below. subduction. This is a relatively short time
compared with some continental stone that is
3.7 Nature, however, is by no means quite 3.9 billion years old. Thus, the sea floor is
so accommodating as to always exactly fit this similar to a conveyor belt moving from zero to
twofold classification. The compositional 180 million years old, then disappearing.
differences of these stone classifications However, because of its comparatively young
represent the end members of a continuous age, oceanic stone lacks the abundant variety of
element spectrum of high Fe, Mg, Ca and low

6Mafic is a word made up from the first letters of its 7Felsic is derived from feldspar and silica, from the high
characterizing components. In this case, ma- from quartz content.
magnesium plus –fic from ferric, which means “of iron
content.”

 2016 Marble Institute of America The Geology of Stone • Page 1-3

types, colors, and textures found in the much Hawaii were born in this manner. Subsea
older continental stone. volcanic activity is continually creating new
oceanic floor and volcanic islands.
3.9.2 The lower crust and upper mantle of
Earth are composed of rocks remarkably 3.10.2 However, not all igneous stone is
similar in composition, closely related to volcanic. All genuine granites8 are solidified
basaltic lava: dark-colored, heavy, with silicate slowly from a melt miles deep in the crust, well
minerals having high amounts of Fe, Mg, and encapsulated and thus well insulated by
Ca-rich silicates and lesser amounts of silica in surrounding solid rock. This is significant to the
the form of quartz (SiO2). The natural process quality of granite dimension stone because
of crustal formation through nearly 4.5 billion slow cooling yields the larger crystals that give
years has chemically differentiated these dark, many commercial granites their distinctive
heavy stones into the lighter-colored and textural character and beauty.
lighter specific gravity stones of the continents.
3.11 Clastic Sedimentary Stone. The
3.9.3 Other stone formation processes that formation of clastic sedimentary stone is
are a part of or affect plate tectonics include relatively uncomplicated compared to the
continental movement and collision, mountain complex chemistry and natural processes
formation, earthquakes, chemical weathering associated with either igneous or metamorphic
of stone, the freeze/thaw cycle, landslides, and stone.
climatic events, such as violent storms,
torrential rain, and floods. 3.12 Clasts are fragments or grains of any
existing stone, produced by one or more
3.9.4 These and other natural processes processes, such as freezing and thawing,
continuously operate to form new stone and to earthquakes, and other events of weathering,
chemically differentiate existing stone both mechanical and chemical. Clasts are also
materials through time, yielding a spectrum of called “detritus;” thus, clastic sedimentary
colors and unique designs in an abundance that stone is sometimes referred to as detrital
satisfies an increasingly demanding market. sedimentary stone.

3.10 Igneous Stone. Igneous stone is 3.13 Sizes of clasts range from boulders to
cooled and solidified from material melted by cobbles, pebbles, sand grains, silt, and clay-
heat from decay of radioactive minerals in the sized particles. They are moved by gravity,
Earth’s crust (lithosphere), and by frictional wind, and water, and are further abraded or
heat caused by crustal movements. The release rounded and dissolved in the process, and
of these powerful forms of thermal energy can sorted and carried vast distances. The rivers of
produce explosive volcanism like the type seen the world are the prime movers of sediment
in mountain ranges such as the Cascades in the while sorting them by size, weight, and shape,
northwestern United States. Mount St. Helens grinding or abrading the particles to very fine
in Washington is an example of this geologic sand, silt, and finally, clay-sized grains carried
process. in suspension to the oceans and deposited on
continental margins. As deposits thicken,
3.10.1 Other volcanic areas known as “hot compaction occurs and the natural process of
spots” are formed from molten rock emerging chemical cementation takes place through time
on the ocean’s floor through stationary spots or to produce clastic sedimentary stone.
plumes or vents in the underlying upper mantle
and crust. The basaltic volcanic islands of

8 Some types of stone defined by ASTM International as

“granite” are not true, geological granites.

Page 1-4 • The Geology of Stone  2016 Marble Institute of America

3.13.1 Chemical alteration is a continual 3.14.6 Particle Name: Clay
process acting on stone, from the moment of Size Range (in mm): <1/256
solidification, exposure and weathering, to its Rock Name: Mudstone and Shale
transportation, deposition, compaction, Stone Abbreviation: Sh.
burial, and cementation throughout the time
that piece of stone exists. Chemical change 3.15 Sandstones and Conglo-
during burial continues. Change continues merates. Sedimentary stones most important
after quarrying, fabrication, and installation on to the dimension stone industry are sandstones
a structure, and faster if water is present. But and some of the smaller-grained
if stone is kept dry, chemical action slows up to conglomerates. Siltstone, shale, and the very
a minimal level. large-grained conglomerates are of less
commercial importance except for landscaping
3.14 Clast Sizes. Clasts are graded and occasional artistic constructions. Siltstone,
according to size, and the resulting stone after where well-cemented and readily available,
compaction and cementation is classified as was utilized as a fieldstone for buildings or
follows: other structural work in earlier centuries.

3.14.1 Particle Name9: Boulders 3.16 Sand Grain Composition. Sand

Size Range (in mm): >256 grains are graded very fine, fine, medium,
Rock Name: Boulder Conglomerate coarse, and very coarse. They may be further
Stone Abbreviation: Cgl. characterized as well-rounded, almost
spherical, to very angular. Angular grains tend
3.14.2 Particle Name: Cobbles to interlock well, and when cemented, are
Size Range (in mm): 64 to 256 desirable in sandstone, just as angular sand is
Rock Name: Cobble Conglomerate desirable for the same reason in masonry.
Stone Abbreviation: Cgl. Sandstones buried over tens to thousands of
feet become compacted, and the flow, often
3.14.3 Particle Name: Pebble miniscule, of chemical-charged aqueous fluids
Size Range (in mm): 2 to 64 proceed to cement the grains with one or more
Rock Name: Pebble Conglomerate of cementing minerals. Chemical activity does
Stone Abbreviation: Cgl. not cease, but continues to cement or de-
cement the stone, or change the stone by
3.14.4 Particle Name: Sand introduction and sometimes substitution of one
Size Range (in mm): 1/16 to 2 mineral for another of both grains and cement.
Rock Name: Sandstone10
Stone Abbreviation: Sst. 3.17 Cementing Minerals. The
common cementing minerals of clastic
3.14.5 Particle Name: Silt sedimentary stone in order of hardness and
Size Range (in mm): 1/256 to 1/16 desirability are the following:
Rock Name: Siltstone
Stone Abbreviation: Sltst. 3.17.1 Silica: Either hydrous or
crystalline, both types are hard and relatively
insoluble.

9 Particle names are simply names for a defined grain sandstone is generally regarded as “quartz” sandstone.
size. They do not suggest the mineralogical content Quartz is among the longest-lasting minerals in the
unless a mineral name precedes the particle name as a environment, resisting chemical degradation and
modifier. abrasion.
10Although sand-sized grains can be from any rock
fragment and one or more of several minerals,

 2016 Marble Institute of America The Geology of Stone • Page 1-5

3.17.2 Carbonate: Even though calcite is fossiliferous limestone, which is not strictly a
soluble in dilute acids like rain, it is a good chemical sedimentary stone (see the Travertine
cement, and much clastic sedimentary stone is chapter).
cemented with calcite and/or a mixture of
calcite and silica cements. Other carbonates 3.18.1 Salt, anhydrite, and gypsum form in
may be less soluble, but these are rare as other marine settings such as the Red Sea,
cements. which has very wide tidal flats in a hot climate
that promotes evaporation and precipitation.
3.17.3 Iron Oxides: These are fairly Even the Mediterranean Sea was a closed basin
common as clastic cements, but tend to be millions of years ago in which thick evaporates
softer and bleed ugly stain. Although some formed similar to those now found in the Dead
excellent sandstones are red to red-brown Sea.
from some iron cement and stained quartz
grains, the better brownstones may have silica 3.19 Metamorphic Stone. Many of the
cements, making them truly excellent, highly most colorful, highly figured, and beautiful
colored stones. dimension stones are the result of
metamorphic processes. The popularity of
3.17.4 Clay Minerals: These are generally these spectacular stones has encouraged the
considered a rather poor cementing medium. exploration for the new types of stone that
Even though clay cemented stone may appear frequently appear in the market. Metamorphic
well-cemented, the clay cement is soft, weak, processes are capable of producing stone in a
easily crushed, and readily removed by water. color palette and textural complexity that
rivals that of igneous and sedimentary
3.17.5 Other mineral cements may be processes.
found from time to time, but are rare.
3.19.1 Metamorphic stone makes up a large
3.17.6 All of the cementing minerals part of all continents, is exposed on all
mentioned in this section, plus some other rare continents, and is found deep beneath the
mineral cements, can combine in various relatively flat areas of continents thickly
mixtures that will bond stone satisfactorily. covered by sedimentary rocks, such as the U.S.
Midwest. It makes up the core areas of
3.18 Chemical Sedimentary Stone. continents. For example, the ancient, complex
This class of sedimentary stone precipitates metamorphics of the Canadian Shield in
from chemically dense bodies of water such as northern Canada comprise the core of the
the Great Salt Lake, the Dead Sea, and other North American continent. The root areas of
closed marine basins lacking outlets. Salt-laden many mountain chains such as the Himalayas,
water flows in and evaporation constantly Rockies, and Urals are the same type of
increases the salt content until precipitation strongly metamorphosed rock that underlies
takes place. Common building stones that are the central Midwest from Ohio to Illinois.
chemical precipitates include travertines
(CaCO3), onyx (CaCO3), alabaster (CaSO4), 3.19.2 Metamorphic stones are among the
and cherts such as flint, jasper, and agate. Chert most interesting of Earth’s products, for they
is a sedimentary deposit of hydrous silica are the only direct evidence of major
(SiO2∙nH2O). The popular dimension stones catastrophic events in the history of the Earth’s
travertine and onyx are chemical crust. Some of this stone is up to 3.8 billion
precipitates of mostly limestone or calcium years old, and has changed in its long existence
carbonate (CaCO3) deposited around ground from igneous to sedimentary to metamorphic.
springs, in caves, or springs in bodies of saline
water, although some travertine is actually

Page 1-6 • The Geology of Stone  2016 Marble Institute of America

3.19.3 Any deeply buried, existing stone– 4.4 Two great energy sources drive the rock
igneous, sedimentary or metamorphic–may be cycle: the sun, and the heat from the Earth’s
subjected to forces that cause profound interior generated from the decay of
mechanical, textural, and ultimately, chemical radioactive materials. The sun heats the Earth’s
changes in the mineral content. gaseous atmosphere, driving the weather
Metamorphosed stone may or may not patterns that cause weathering and erosion of
resemble its parent stone. Metamorphism is any exposed or nearly exposed rock —the
caused by regional-scale crustal movements beginning of the sedimentary cycle. Biological
and mountain-building forces, or by local activity on the Earth’s surface, and to some
crustal disturbance, at temperatures about depth beneath it, also interacts with the
200ºC to near-melting, ≈700-800ºC, and chemical processes affecting stone.
pressures from around 450,000 pounds per
square inch (psi) to several million psi in the 4.5 The rock cycle has been going on
presence of chemically charged aqueous fluids continuously for much of the Earth’s 4.5 billion
through time. years. Some zircon grains (zirconium silicate,
ZrSiO4) from an Australian sandstone have
3.19.4 Metamorphic rock produced from been through the rock cycle five times,
widely variable conditions yields three distinct covering more than 3.9 billion years.
grades of metamorphism, from low-grade Continuous cycling through the multiple
through medium- to high-grade metamorphic processes, mechanical and chemical, serves to
rock, each characterized by specific stone chemically and mineralogically differentiate
colors, textures, and mineral content. Stone of stone; thus, the rock cycle allows continental
all metamorphic grades can be found as stone to develop into the wide range of colors
beautiful dimension stone of many types, and varieties of beautiful dimension stone that
including slate, quartzite, marble, and have been used by mankind throughout
serpentine. history.

4.0 THE ROCK CYCLE

4.1 Basic processes and relationships

inherent in the geological concept known as
“the rock cycle” help to understand the variety
and complexity of stone.

4.2 As shown in the rock cycle

illustration on the following page, the curved
arrows at each stone type indicate that a new
igneous, metamorphic, or sedimentary stone
can be developed from an existing stone by a
repetition of melting and metamorphism, or by
the weathering, transportation, deposition,
compaction, and cementation processes.

4.3 The straight arrows from one stone type

to another show that any of the three basic
types of stone can be produced from an existing
stone of one of the other types.

 2016 Marble Institute of America The Geology of Stone • Page 1-7

 THE ROCK CYCLE

SEDIMENTARY Solar
Rocks Heating
SEDIMENTARY
Rocks
BIOLOGIC LIFE ZONE

IGNEOUS METAMORPHIC
Hi Pressure
(Melting)
Heat
Heat from
from
decay
Decay of of
Radioactive Isotopes
Radioactive Isotopes © ccr.03

The geological concept of the rock cycle illustrates that new igneous, metamorphic, or sedimentary
stone can form from existing stone of another type through the repetition of natural processes.

NOTES:
Each Material chapter has a section that further
details geological information about that
specific stone.

Page 1-8 • The Geology of Stone  2016 Marble Institute of America

STANDARDS AND 2.0 WHY ASTM STANDARDS
SPECIFICATIONS FOR AND OTHER LIKE STANDARDS
STONE PRODUCTS ARE IMPORTANT

1.0 ORGANIZATIONS 2.1 In today’s building environment, the

emphasis is on safe, permanent, low
1.1 ASTM International maintenance products, of which stone leads the
100 Barr Harbor Drive list in the minds of architects, designers, and
West Conshohocken, PA 19428-2959 U.S.A. consumers worldwide.
Telephone: 610.832.9585
Fax: 610.832.9555 2.2 Without a consistent, realistic set of
www.astm.org standards and testing procedures for stone
European Office: products, the stone industry as a whole would
Telephone: 146.243.7933 be in disarray. The standards that have been
Fax: 146.243.3678 developed and set in place for these products
are important tools to help protect end users,
1.2 American National Standards individual companies, and the industry from
Institute (ANSI) negative effects related to product failures.
25 West 43rd Street, 4th Floor Materials standards help to prevent the use of
New York, NY 10036 U.S.A. stone products for unsuitable applications. For
Telephone: 212.642.4900 instance, without the minimum standards for
Fax: 212.398.0023 Abrasion Resistance of Stone Subjected to Foot
www.ansi.org Traffic (ASTM C241), it would be more likely
that very soft, easily damaged materials would
1.3 NSF International be installed in commercial applications. This
P.O. Box 130140 may cause the owner to incur additional cost
789 N. Dixboro Road for repair and maintenance, and negatively
Ann Arbor, MI 48113-0140 U.S.A. affect the reputation of the stone industry as a
Telephone: 734.769.8010 whole.
Fax: 734.769.0109
www.nsf.org 2.3 These standards also serve as
European Office: benchmarks for quality limits of products. If a
Kleine Kloosterstraat 6 stone with a below-minimum flexural strength
1932 Zaventem is used for a lintel, then it may be more likely
Belgium to fail, thus causing damage and possible injury.
Telephone: 32.2.771.36.54 Interior or exterior flooring or paving with an
Fax: 32.2.763.00.13 inadequate slip resistance level will more likely
cause slipping accidents in public or private
1.4 European Commission for projects.
Standardization (CEN)
36 rue de Stassart 3.0 HOW AND WHEN THESE
B-1050 Brussels STANDARDS APPLY
Belgium
Telephone: 32.2.550.08.11 3.1 As stone industry professionals, it is our
Fax: 32.2.550.08.19 task to apply the correct standards to materials
www.cenorm.be at appropriate times in order to keep the stone
industry strong and to remain a reliable source
of quality products.

 2016 Marble Institute of America Standards and Specifications for Stone Products • Page 2-1
3.2 Most architectural specifications require use, then avoid marketing it for that use. If
that stone meet certain specified ASTM or testing is not available, require that it be done
other testing standards before it will be or avoid the product’s use.
accepted for use. Some products on the market
today have not been tested for quality standards 4.0 ASTM INTERNATIONAL
that are required for certain projects. The
required testing should be reviewed and, if test 4.1 The American Society for Testing and
results are not available for the stone product, Materials International (ASTM), founded in
then testing should be performed by the quarry 1898, is a not-for-profit organization that
or representative company as required. Some provides a global forum for the development
quarries and their representatives do not and publication of voluntary consensus
embrace this idea because their products can be standards for materials, products, systems, and
marketed to homeowners and residential services. Over 30,000 individuals from 100
projects without the need to perform testing. nations are the members of ASTM
It is up to our industry to know how to identify International, who are producers, users,
these products and make sure to request the consumers, and general interest parties such as
required material data needed. government representatives and academicians.

3.3 Testing of stone can be performed by 4.2 Committees are established that focus
other companies in the event that required test on and have jurisdiction over standards for
data are not available. Independent labs can different designations, such as Dimension
perform the appropriate tests and provide the Stone (Committee C18) or Cement
information in a well organized, professional (Committee C01). These committees are
report. made up of several subcommittees which are
tasked to develop and discuss individual
3.4 It is important to know when a certain segments within the committee’s jurisdiction.
test is not required for a product. For example, For example, one subcommittee may deal with
a test for Slip Resistance would not be the development of standards dealing with Test
necessary for stone used in a vertical Methods of Dimension Stone, and another with
application, which will never receive foot Anchorage Components and Systems for
traffic. Some examples are not as easily Natural Stone. These committees meet on a
established. For instance, what are the needs regular basis to discuss and present information
for testing a stone to be used for interior for each new or existing standard.
flooring in a commercial application where the
stone is installed over a raised floor deck 4.3 The entire membership of ASTM
subject to deflection, and will be subject to International votes on whether a standard is
traffic from pedestrians and cleaning carts suitably developed and researched before it is
weighing 1,000 pounds? It may be required forwarded for final approval. Negative votes
that the stone of choice meets standards related cast during the balloting process are fully
to Slip Resistance, Abrasion Resistance, resolved before forwarding.
Absorption, Compressive Strength, and
Bending Strength. These are all physical 4.4 Companies, agencies, and individuals
requirements of the stone product during use ASTM standards. Buyers and sellers of
everyday use. materials, products, and services include these
standards in contracts; engineers, scientists,
3.5 Be aware of the requirements of architects, and designers use them in their
performance that will be placed on the stone at work; government agencies reference them in
the time of installation, and in the future. If a codes and regulations; and many others refer to
stone has proven not to perform for a particular them for performance information.

Page 2-2 • Standards and Specifications for Stone Products  2016 Marble Institute of America
 Standardization (ISO), and, via the U.S.
4.5 ASTM International is recognized National Committee (USNC), the
globally and continues to review and develop International Electrotechnical Commission
new standards needed in a wide range of (IEC). In many instances, U.S. standards are
materials. taken forward to ISO and IEC through ANSI or
the USNC, where they are adopted in whole or
5.0 ANSI in part as international standards.

5.1 The American National Standards 6.0 NSF INTERNATIONAL

Institute (ANSI), founded in 1918 by five
engineering societies and three government 6.1 NSF International, formerly the
agencies, is a private, not-for-profit National Sanitation Foundation, is a not-for-
organization that administers and coordinates profit, non-governmental organization that
U.S. voluntary standards and conformity provides standards, certification, education,
assessment activities. The Institute represents and risk management services in the fields of
the interests of its nearly 1,000 company, public health safety and the environment. NSF
organization, government agency, was founded in 1944 in response to a need for
institutional, and international members a single set of food equipment sanitation
through its office in New York City and its standards that manufacturers and operators
headquarters in Washington, D.C. could accept and regulators could adopt into
code. NSF has 21 standards for all types of
5.2 ANSI currently provides a forum for products and materials used in food service.
over 270 ANSI-accredited standards The standards contain requirements for
developers representing approximately 200 materials, design, construction, and
distinct organizations in the private and public performance of food service equipment to
sectors. These groups work cooperatively to ensure that it is safe and can be kept sanitary.
develop voluntary national consensus standards Today, NSF Food Equipment Standards are
and American National Standards (ANS). globally recognized, and certification to the
standards is required by regulators, specified
5.3 The ANSI standardization process by end users, and marketed by manufacturers.
provides and promotes standards that
withstand scrutiny, yet protect the rights and 6.2 NSF Material Requirements –
interests of all participants. This process helps Standard 51. An important component of the
quicken the market acceptance of products, NSF Food Equipment Standards is the material
while advising how to improve the safety of requirements. While each standard can have
those products to protect consumers. its own unique material requirements, all food
equipment standards reference NSF/ANSI
5.4 U.S. standards are promoted Standard 51-2002, Food Equipment Materials.
internationally by ANSI. The organization also The material require-ments help to ensure that
advocates U.S. policy and technical positions in only nontoxic and cleanable materials are used.
international and regional standards Material suppliers have utilized NSF
organizations, as well as supporting the Certification to Standard 51 as an effective
acceptance of international standards as U.S. method for marketing their products to food
standards where they meet the needs of the equipment manufacturers. Manufacturers who
user community. purchase NSF-certified materials have one less
item of concern when getting their own
5.5 The Institute is active internationally equipment certified.
with the International Organization for

 2016 Marble Institute of America Standards and Specifications for Stone Products • Page 2-3
6.3 Applying Standard 51 to Natural 7.0 ASTM SPECIFICATIONS
Stone. When reviewing granite, marble, and AND STANDARDS
other natural stones to the requirements of
Standard 51, there are essentially two issues 7.1 Material Specifications
that can determine its acceptance: smoothness
and toxicity. 7.1.1 ASTM C503, Standard Specification for
Marble Dimension Stone (Exterior)
6.4 Smoothness. The standard defines
“smooth” as free of surface imperfections that 7.1.2 ASTM C568, Standard Specification for
are detectable by visual or tactile inspection. Limestone Dimension Stone
This includes pits, cracks, and crevices. This
concern for smooth surfaces applies not only to 7.1.3 ASTM C615, Standard Specification for
the natural surface, but also the treatments Granite Dimension Stone
used to make a surface smooth. Application of
a coating is sometimes considered a way of 7.1.4 ASTM C616, Standard Specification for
addressing smoothness; however, coatings Quartz-Based Dimension Stone
have a tendency to chip or flake over time, thus
creating their own difficult-to-clean surface. 7.1.5 ASTM C629, Standard Specification for
As a result, there is a prohibition on the use of Slate Dimension Stone
coatings for surfaces subjected to cutting and
chopping actions, such as countertops and 7.1.6 ASTM C1526, Standard Specification
cutting boards. It is important to note that this for Serpentine Dimension Stone
prohibition would not necessarily apply to all
surface treatments the natural stone industry 7.1.7 ASTM C1527, Standard Specification
might use. Sealers that are buffed off to the for Travertine Dimension Stone
point where they only remain to fill surface
imperfections are not considered a “coating” 7.2 Test Standards
for the purposes of NSF standards, and could
potentially be used on countertops and cutting 7.2.1 ASTM C97, Standard Test Method for
boards. Absorption and Bulk Specific Gravity of
Dimension Stone
6.5 Toxicity. Standard 51 requires that
materials meet FDA regulations for their 7.2.2 ASTM C99, Standard Test Method for
intended end use, as specified in the Code of Modulus of Rupture of Dimension Stone
Federal Regulations, Title 21 (21 CFR).
Applying Standard 51 toxicity requirements to 7.2.3 ASTM C120, Standard Test Method of
the stone is fairly easy. Because natural stone Flexure Testing of Slate (Modulus of Rupture,
does not fall under the scope of 21 CFR, we Modulus of Elasticity)
simply conduct extraction testing to verify that
the material does not contain any regulated 7.2.4 ASTM C121, Standard Test Method for
heavy metals. When sealers are used, NSF Water Absorption of Slate
must have verification from the sealant
manufacturer that it meets 21 CFR. An 7.2.5 ASTM C170, Standard Test Method for
alternative is that the sealant manufacturer can Compressive Strength of Dimension Stone
obtain an NSF certification.
7.2.6 ASTM C217, Standard Test Method for
Copies of each standard can be obtained online Weather Resistance of Slate
or by fax from the source.

Page 2-4 • Standards and Specifications for Stone Products  2016 Marble Institute of America
7.2.7 ASTM C241, Standard Test Method 7.3.7 ASTM C144, Standard Specification
for Abrasion Resistance of Stone Subjected to for Aggregate for Masonry Mortar
Foot Traffic
7.3.8 ASTM C150, Standard Specification
7.2.8 ASTM C880, Standard Test Method for Portland Cement
for Flexural Strength of Dimension Stone
7.3.9 ASTM C207, Standard Specification
7.2.9 ASTM C1201, Standard Test for Hydrated Lime for Masonry Purposes
Method for Structural Performance of Exterior
Dimension Stone Cladding Systems by 7.3.10 ASTM C270, Standard Specification
Uniform Static Air Pressure Difference for Mortar for Unit Masonry

7.2.10 ASTM C1352, Standard Test 7.3.11 ASTM C482, Standard Test Method
Method for Flexural Modulus of Elasticity of for Bond Strength of Ceramic Tile to Portland
Dimension Stone Cement Paste

7.2.11 ASTM C1353, Standard Test 7.3.12 ASTM C630/C630M, Standard

Method for Abrasion Resistance of Dimension Specification for Water-Resistant Gypsum
Stone Subjected to Foot Traffic Using a Rotary Backer Board
Platform Abraser
7.3.13 ASTM C920, Standard Specification
7.2.12 ASTM C1354, Standard Test for Elastomeric Joint Sealants
Method for Strength of Individual Stone
Anchorages in Dimension Stone 7.3.14 ASTM C1242, Standard Guide for
Selection, Design, and Installation of Exterior
7.3 Other Application Standards Dimension Stone Anchors and Anchoring
Systems
7.3.1 ASTM Manual Series: MNL 21.
Modern Stone Cladding: Design and 7.3.15 ASTM C1515, Standard Guide for
Installation of Exterior Dimension Stone Cleaning of Exterior Dimension Stone,
Systems. 1995. Vertical and Horizontal Surfaces, New or
Existing
7.3.2 ASTM A666, Standard Specification
for Annealed or Cold-Worked Austenitic 7.3.16 ASTM C1528, Standard Guide for
Stainless Steel Sheet, Strip, Plate, and Flat Bar Selection of Dimension Stone for Exterior Use

7.3.3 ASTM B221, Standard Specification 7.3.17 ASTM C1721, Standard Guide for
for Aluminum and Aluminum-Alloy Extruded Petrographic Examination of Dimension Stone
Bars, Rods, Wire, Profiles, and Tubes
7.3.18 ASTM C1722, Standard Guide for
7.3.4 ASTM C36/C36M, Standard Repair and Restoration of Dimension Stone
Specification for Gypsum Wallboard
7.3.19 ASTM E72, Standard Test Methods
7.3.5 ASTM C91, Standard Specification of Conducting Strength Test of Panels for
for Masonry Cement Building Construction

7.3.6 ASTM C119, Standard Terminology 7.3.20 ASTM E119, Standard Test Methods
Relating to Dimension Stone for Fire Test for Building Construction

 2016 Marble Institute of America Standards and Specifications for Stone Products • Page 2-5
7.3.21 ASTM E575, Standard Practice for
Reporting Data from Structural Tests of
Building Constructions, Elements,
Connections, and Assemblies

7.4 ANSI Specifications and Standards

7.4.1 ANSI A10.20, Safety Requirements

for Ceramic Tile, Terrazzo and Marble Work

7.4.2 ANSI A108, Standards for

Installation of Ceramic Tile

7.4.3 ANSI A118, Specifications for

Mortars and Grouts

7.5 NSF/ANSI Specifications and

Standards

7.5.1 NSF/ANSI Standard 51, Food

Equipment Materials

7.6 CEN Specifications and

Standards

7.6.1 CEN specifications and standards are

in the process of being compiled. This
information will be available at a later date.
All standards and specifications are revised or
updated periodically. The current status of any
standard or specification can be confirmed by
contacting the proper authority.

Page 2-6 • Standards and Specifications for Stone Products  2016 Marble Institute of America
Dimension STONE there are several significant influencing factors.
Among them are aesthetics, color, strength,
SELECTION durability, design, texture, finish, size,
thickness, availability, stone testing, stone
1.0 INTRODUCTION sampling, and cost. The effects any of these
factors may have on another can influence the
1.1 Stone Selection Options. Architects final choice. But aesthetic considerations
and builders throughout the ages have chosen nearly always drive the selection process.
stone for its permanence and beauty. Where
selection was once limited mainly to what was 2.0 AESTHETICS &
locally available, today’s stone marketplace is APPEARANCE
virtually worldwide. With the broad and
growing array of options, the stone selection 2.1 Factors beyond Appearance. A
process has become more complex under the palette of colors and a variety of textures
weight of multiple considerations. provide ready options in the aesthetic choices
among dimension stones. Yet, as the following
1.2 Stone Is A Product Of Nature. pages suggest, it is advisable to examine and
Dimension stone has its own unique qualities apply other factors that may recommend
that not only distinguish it from man-made alternatives to a selection based purely upon
materials, but also should be considered in aesthetic appeal, particularly on exterior
selecting it for a particular project. Stone is not applications. A stone that is most desirable in
manufactured; it is a product of nature. Blocks appearance, for example, may lack needed
are removed from the quarry, slabs are cut strength or durability for a particular
from these blocks, and the slabs are further application.
fabricated into the final stone to be installed.
Each block is different; each slab is different. 2.2 Exterior Cautions. The cautions
Skillful blending or matching of the dimension regarding exterior applications are of far less
stone blocks, veneer panels, tops, etc., results concern when considering interior
in a beautiful blending of nature’s variety and installations. Aesthetics can be allowed much
man’s design. In contrast to the uniformity of freer rein for stone that is not subjected to the
materials produced by machine or assembly elements.
line, dimension stone’s naturally varied
appearance has wonderful character. 2.3 Variegated or veined materials,
“Uniformity of material,” when applied to especially marbles, that offer interesting colors
natural stone, is a term of relative value that and patterns and that are by their nature
needs to be understood when making a “faulted” and not generally suitable for exterior
selection. use are often highly valued for their decorative
qualities in interior installations.
1.3 Exterior vs. Interior Installations.
The factors to be weighed in selection may not 2.4 Translucence occurs in some white or
be equally applicable to exterior and interior very lightly colored marbles and onyxes having
installations. The following discussion is a crystal structure that will transmit light to
therefore divided, as appropriate, between varying degrees depending upon stone
exterior and interior uses if the factors do not thickness and finish. Translucence can be an
readily apply to both. aesthetically intriguing decorative attribute.
1.4 Selection Influencers. While any 2.5 Sample Variations. Assuming that all
number of stipulations may direct selection of critical factors support the desired choice in a
a particular stone for a specific application, given application, expectations as to final

 2016 Marble Institute of America Dimension Stone Selection • Page 3-1

appearance must be realistic. Unless a choice is 2.9.3.1 Flamed or Thermal: Plane surface
made and marked on an actual slab, variation with flame finish applied at high temperature
from a submitted sample is a fact and should by mechanically controlled means to ensure
not come as a surprise. uniformity; changes the color of the stone.

2.6 Fleuri Cut Stones. Many dimension 2.9.3.2 Water-jet Flamed Finish: Gives a
stones today are being cross cut or fleuri cut. more uniform, textured finish and allows more
This is true in travertines and some granites, of the natural color to show.
for example. Many times, the reason this is
done is to avoid a directional vein and achieve 2.9.3.3 Sandblasted: Coarse plane surface
a more “cloudlike” effect. In any case, the produced by blasting an abrasive, allowing a
Specifier and the Stone Supplier should know if fine-textured finish; may lighten the color.
this is done and investigate the test data, as it
may change from normal, conventional means. 2.9.3.4 Bush-hammered: Coarsely text-
See illustration at the close of chapter 7. ured surface produced by hammering, and may
vary according to the metallic head used, from
2.7 Filling Might Be Required. Another fine point to very coarse, and may leave high,
issue is where cross cut (fleuri cut) stones are lighter-colored markings.
used. As in the case of travertine, a limestone,
it may require filling with cement or epoxy, 2.9.3.5 Natural Cleft: A cleavage face
which may or may not hold up under heavy formed when the stone is split into any
traffic conditions, and the fills may come out. thickness.

2.8 Choosing a Finish. Choosing the 2.9.3.6 Picked, Hand-hewn Rock Face:
manner in which stone will be finished is an Using a chisel or other metallic object that
integral part of the selection process. Finish gives deeper indentations and cleavage to the
can be anything from saw cut to high polish. A stone.
high polish will bring out the color of the stone
to its fullest, because it will optimally reflect 2.9.3.7 Sawn: Usually refers to slabs
the light. Conversely, a textured finish will coming from a gang saw, with blades that are
always appear lighter. A combination of applied to the block of stone using water and
finishes can add interest to a chosen stone. New fine grit.
finishes are appearing on the market yearly, so
check and investigate all finishes available with 2.9.3.8 Gauged: Done by a machine,
your Stone Supplier. usually with circular abrasives to grind the
material to a specific thickness.
2.9 Finishes commonly available are:
2.9.3.9 Planed: Usually refers to slate,
2.9.1 Polished: Mirror gloss, with sharp where a metallic scraper peels a layer of stone,
reflections. making the stone flat and smoother.

2.9.2 Honed: Dull sheen, without re- 2.9.3.10 Acid Washed: Usually applied to a
flections, achieved by abrasive heads. The sawn finish to lower the degree of sawn marks
degree of honing depends on the stone, but showing, yet maintain a natural textured finish.
may vary from light to heavy.
2.9.3.11 Tumbled: Method of putting tiles
2.9.3 Fine Rubbed: Smooth and free in a mixing container with sand and rotating
from scratches; no sheen. them, allowing the edges and corners of the
tiles to chip.

Page 3-2 • Dimension Stone Selection  2016 Marble Institute of America

 even, visually pleasing result in the finished
NOTE: Many new finishes are being applied to surface.
stone as the market demand increases and new
uses for stone are being conceived. In some 3.5 Matched-vein Patterns. In contrast
productions, combinations of finishes on the to modular tiles, panels cut from the slab
same stone are being made. Check with the usually will give the best results aesthetically.
Supplier to verify the finish and how it was There are different ways that veined dimension
made in order to specify properly. stones or other stones can be matched to form
a pattern, and stones must be of types that lend
3.0 DESIGNING WITH themselves to specific pattern arrangement.
DIMENSION STONE Patterned and matched panels require that the
material be selected and thus, often increases
3.1 Design Considerations are nearly the cost of the stone. See diagrams at the close
equal among the factors of aesthetics, strength of chapter 7 for a detailed description of vein
and durability. This is particularly true of patterns.
interior applications. The imagination of
Designers is boundless, and it is the Fabricator 3.6 Mixing Types of Materials. Designs
or Supplier who must counsel the design calling for a mixture of stones with different
professionals as to what is feasible and what is physical properties, while aesthetically
not. Stone is not a plastic material. It is rigid interesting, can give rise to problems of wear
and breakable when handled in fabrication. and of maintenance, mainly on floor areas. Re-
polishing will pose problems, should that need
3.2 Yield. Before making final selection of arise. The Specifier should be aware that
a stone, particularly on a larger project, take mixing types of stones means there will be
wastage into account to make certain there will different abrasion resistance levels as well as
be enough material to complete the project. different densities of stones that must be
An often-forgotten fact is that the material considered in the long-term maintenance of the
from a quarry today may be different from stone and its wearability.
what was available six months ago. Further,
there may be more than one quarry of the 4.0 EXTERIOR APPLICATIONS
material. The criteria of the Producer to select
stone also vary from quarry to quarry. 4.1 Strength. A most important concern
when selecting stone is strength. This is
3.3 Modular Stone Tiles. For ease and particularly true in cases of exterior stone
economy, modular stone tiles offer a good cladding for buildings over two stories high.
alternative to stone panels for walls and level Strength in those situations should be the
floors. Thin stone tiles, varying in thickness determining factor in the final selection of the
from 1 cm to 1.5 cm, are available in modular stone.
sizes of 12" x 12", 16" x 16", 18" x 18", and 4.2 Exterior Stone Stresses. Exterior
other sizes, up to a maximum of 24" x 24". stones must be able to withstand the stresses
The proper tile thickness for the installation that will be imposed upon them, such as the
will depend upon the stone type selected and following:
the modular size of the tile specified.
4.2.1 Gravity load, which must be borne by
3.4 Mixing Tiles. The final look of mixed the anchorage system.
tiles may fall short of appearance expectations,
especially if the stone is variegated and veined. 4.2.2 Windload, which exerts both positive
The Installer should mix tiles from different and negative pressure on the panels, and is
boxes during the installation to achieve a more

 2016 Marble Institute of America Dimension Stone Selection • Page 3-3

typically higher at building corners and other porosity is important, as well as the density of
areas of discontinuity. the stone. The finish applied to the stone will
be a factor in the slip resistance specified for the
4.2.3 Water vapor, which must be released area.
to prevent condensation and efflorescence
problems. 4.5 Durability. For durability, exterior
stone should be free from structural defects
4.2.4 Freeze/thaw cycles, which can cause and varying characteristics of vein structure,
stone to crack and joints to fail. scaling planes, hairline cracks, earthly parts,
and cavities. Panel dimensions should be
4.2.5 Structural contraction, which controlled in size for optimal results.
occurs during the curing stage of the concrete.
4.6 Granites have been historically favored
4.2.6 Creep, or permanent structural for exterior use. Their composition makes
distortion, which takes place progressively them both resistant and stable, and surfaces
over the years until the structure has settled. will hold a high polish longer. As a rule,
weaker stones require greater and more costly
4.2.7 Elastic distortion, which is caused by reinforcement.
movement produced by load charges on the
structure. 4.7 In dry and temperate climates,
softer stones like limestones can also be used
4.2.8 Thermal expansion and con- successfully in thicknesses appropriate to the
traction, which affects stone and other job. However, exteriors of gray or black
structural elements limestones with a bituminous or carbon
composition should be avoided because the
4.2.9 Absorption or porosity of the stone action of atmospheric agents will rapidly cause
is a factor, as it will affect the durability and life the surface to deteriorate. Other stones
of the stone, as well as its appearance. considered inappropriate are the ophicalcites
and the breccia in general, as well as all stone
Note: The durability of the installation method containing pyrites, which may produce rust
for walls is determined by the substrate it is spots when exposed to air and moisture.
being applied to and the anchoring method
being used. Consult an engineer to evaluate all 5.0 INTERIOR APPLICATIONS
installation issues.
5.1 Selection Criteria. The fact that
4.3 Test Data. Where structural capability interior stone is sheltered from the action of
is critical, test data for compressive strength, the elements makes all types of stone, from the
flexural strength, modulus of elasticity, and hardest granite to the softest limestone,
sheer strength should be studied. Where suitable for application. Criteria for the
weather is a factor, absorption, porosity, and selection of interior stone for both commercial
permeability studies should be made. and residential projects tend to be similar.
Freeze/thaw compressive strength testing Selection considerations focus on whether the
should also be carried out. For walls, the type application will be on vertical or horizontal
of anchoring, and performing an anchorage planes.
pull-out test, are important.
5.2 Interior Vertical Surfaces. Nearly
4.4 High-traffic Floor Areas. For high- any stone may be chosen for interior cladding
traffic floor areas, abrasive hardness testing of commercial buildings. Practical
should be a requisite. The absorption or considerations for highly used areas, however,

Page 3-4 • Dimension Stone Selection  2016 Marble Institute of America

lead to stones that are dense, resistant, and 5.7 In light-volume traffic and
easily maintained. These prove to be the best residential areas, where problems of etching,
choice when aiming for a long-term scratching, and staining are minimal, it is quite
investment. acceptable to make a selection based mainly on
aesthetics and choose a highly polished floor if
5.3 Water Resistance. The action of desired. In all cases, proper maintenance must
water in areas such as fountains and showers is be done.
a factor to be reckoned with. Stones must be
able to withstand frequent or continuous water 5.8 Countertops. Stones for kitchen and
projections, and in the case of showers, the lavatory tops should be chosen with regard to
presence of hot steam. Again, the best results functionality. Foods and their handling will
are obtained with a dense, resistant stone, such affect long-term appearance as acids and grease
as a granite, or a compact stone with a low come in contact with the surface. Not all stones
absorption coefficient. The action of water on are resistant to staining; therefore, selection
polished marble or limestone might cause should be carefully considered. In all cases and
surface dulling, spalling, warpage, or regardless of the type of stone, spills should be
deterioration of stone over time. wiped up immediately and cutting knives not
used directly on the surfaces. There are also
5.4 Interior Horizontal Surfaces. nontoxic sealers (necessary in food preparation
Traffic is obviously a major consideration in areas) that can improve the performance of a
selecting floor stone, whether for heavy, stone to a great degree.
medium, or light duty. In heavy-traffic
situations, floors need to withstand vehicles or 5.9 Lavatory Tops. As a rule, lavatory
carts, stiletto heels, mud and sand, salting tops in residential bathrooms can be chosen
compounds, spilled high-acidity liquids, and according to taste, since the surface receives
other pollutants and indignities. little abuse other than pollutants that might be
contained in cosmetics.
5.5 Heavy-volume traffic and abuse
require stone of maximum resistance–granite, 5.10 MIA Statement of Position on
quartzite, or highly compact marble, Sealing Natural Stone Countertops.
depending on the degree of punishment it must Most granite countertops do not need to be
take. Testing for hardness as measured by sealed. Before 1995 there were very few
ASTM C241 and discussed elsewhere in this quality penetrating sealers on the market and
manual can help in the selection process. there were very few cases of staining. Both
prior to and after the availability of penetrating
5.6 For medium-volume traffic, stones sealers, no cases of food poisoning, radon, or
can be somewhat softer. Many dimension food preparation issues associated with treated
stones will perform well, if properly or untreated granites have been reported. If a
maintained. There are good methods and homeowner cleans their countertops after each
maintenance products available to preserve the meal, they will rarely, if ever, have staining or
stone’s appearance. Generally, it is cleanability issues with granite. All this being
recommended that a dimension stone floor said, many granite countertops receive
receive a honed rather than a highly polished additional benefit from being sealed. That
finish in commercial applications. Etching, benefit is the further reduction of moisture
scratching, and traffic paths will be far less migration into an already moisture resistant
obvious on a honed surface, thus making for surface.
easier maintenance.
Should natural stone counters be sealed? In
many cases it makes sense to seal marble and

 2016 Marble Institute of America Dimension Stone Selection • Page 3-5

granite countertops with a quality sealer. The historical data is sufficient on small jobs, but on
product should have a life expectancy of ten to larger jobs historical test data should only be
fifteen years and be of an oliophobic (resistant taken as indicative, and new tests should be run
to water and oil based stains) nature. Once on the specific stone from the specific quarry to
properly sealed, the stone will be more be used.
resistant against everyday dirt and spills.
7.0 SAMPLING
In today’s natural stone industry, many species
of granite receive a resin treatment at the 7.1 Stone Samples and Mockups.
factory where the blocks of granite are cut into Preparation and supply of dimension stone
slabs and then polished. The treatment is used samples and mockups are often expensive and
to fill microfissures, indentations and other time-consuming, but an essential part of stone
minor characteristics that are found in many projects. Samples and mockups help ensure
natural stones. The reason for the resin that materials meet contract requirements.
treatment is to address what most consumers
consider as imperfections, but in reality are 7.2 Promotional samples are for color
“birth marks.” The consuming public gravitates consideration only, but must be representative
to perfection, defined as no “birth marks,” and of the color and finish being proposed for use.
so the marble and granite industry tries to They should be supplied in small sizes, such as
fulfill the desire. Both resined as well as 3" x 4", 4" x 6", or 6" x 6".
unresined slabs will outlast most of our
lifetimes. Granite should, and in most cases 7.3 Project samples should be 1' x 1' in
will, be the last countertop surface a person size or larger. Care must be taken to select
will buy, providing a strong return on samples that accurately reflect the shades,
investment. The bottom line: Sealing resin markings, and anticipated ranges of color,
treated countertops may increase the resistance texture, finish, veining, filling, and other
of the already resistant nature of stone characteristics of the variety of stones
(adopted 11/8/06). specified.

6.0 TESTING FOR PHYSICAL 7.4 Large Projects. For very large
PROPERTIES projects, multiple samples are needed in order
to show the range of variations. These are
6.1 ASTM Tests. Stone is tested under a normally assembled by selecting from the
rigorous set of standards developed by the blocks that best meet the requirements at that
ASTM International, the world’s largest point in time. Sometimes visits to the quarries
voluntary standards development organization. become a necessary step in the selection
process. Selecting slabs to be cut for the
6.2 Purpose of Tests. The tests apply project is necessary to see the overall variation
standard methods to uniformly evaluate stone of the stone and finish to be used. In all cases,
characteristics and performance. ASTM availability of the material should be secured.
standards are the recommended guidelines for
installation in the stone industry. See Chapter 7.5 Number of Samples. The number of
2 for more information about this organization sample submissions required on a specific
and a list of ASTM specifications and standards. project depends primarily on the amount and
particular use of the stone required. However,
6.3 Original Test Data. The Specifier has there should never be fewer than two sets of
the right to request from the Supplier original samples submitted. Control samples should be
test data on the stone to be used and verify the kept by the Architect, Contractor, and
age of the test and its validity. In some cases

Page 3-6 • Dimension Stone Selection  2016 Marble Institute of America

Producer for verification of the selection meaningless if all the other information is not
approved. supplied.

7.6 For stone that will be matched, 7.9 Viewing Samples. When natural
prepare at least two sets of four matched stone samples are viewed for approval, the
samples each, showing proposed veining, viewer should be no closer than 6 ft. (2 m)
flows, movements, texture, and range in each from the sample surface and viewing from an
set. angle normal to the surface. Natural light is
preferred, striking the samples at an angle
7.7 Support Documentation. Depend- normal to the surface.
ing on the stone selected and quantity required,
a mock-up containing a full range of colors may 8.0 COST
be needed to further define the texture and
characteristics of the stone. The Specifier or 8.1 Pricing Stone for the Job. A key
Buyer should request all samples and factor in determining which stone to use will
submission of stone be accompanied by the be the price. Today, thanks to the development
following in writing: of new technologies, stone is plentiful and
competitively priced. There are many
7.7.1 Actual name of stone and name of stone alternatives in stone selection, with a range of
as applied by the Quarrier, as well as alternate prices to fit any budget. The Specifier should
names of stones in the marketplace, if any are ask for a budget price when initially
known. considering a stone for the stone only. In the
final consideration and determination, the
7.7.2 Country or state of origin. Specifier should know the real cost of the stone
based on the design and its installation costs to
7.7.3 Quarrier, if known. see if the stone fits into the budget of the job.

7.7.4 ASTM test data or European equivalent 8.2 Size of stone is also important. Not all
for first evaluation purposes. stones are available either in the size being
designed or to get the best yield from the
7.7.5 Age of sample, if known. blocks or boulders. Price will be determined
many times by the size and waste factor of the
7.7.6 References of where this stone has been blocks in relation to the finished project.
used near where the job may be located.
8.3 Stone Thickness. In the past,
7.7.7 Photos of slabs showing more range of buildings were erected using blocks or thick
the material and other finishes available. Define slabs. Now, cladding systems make it possible
whether there is more than one quarry and bed to use panels only ¾" or 1¼" thick, and with a
level of quarry where this stone is located. notable reduction in the cost of stone. The
thickness of the stone will be determined by
7.8 This information will assure the engineering and the anchoring system for the
Specifier of writing a specification that will specific stone.
control that the material being specified will
indeed be the stone to be used on the job. 8.4 Modular thin stone tile, a product
of modern technology cut to a thickness of only
Note: As an example, specifying White 1 cm, is suitable for many applications and is
Carrara (a generic name with over 30 quarries, competitive in price. These panels and tiles
and each quarry having possibly 4 selections) is compare very favorably with other natural and
manufactured products available for

 2016 Marble Institute of America Dimension Stone Selection • Page 3-7

construction, and have the added advantage of Specifier should be aware of the maintenance
conferring character and durability to the required to maintain the color and finish of the
structure. stone for years to come. Ask the Stone Supplier
and Salesperson for maintenance suggestions or
8.5 Multiple Factors Affect Price. requirements. Investigate with authoritative
Many factors determine the price of a maintenance companies what they recommend
particular stone. Availability, ease of for a specific stone and the cost factors involved
extraction, market demand, quality, and in maintaining the stone. The more
transportation are a few of the variables that knowledgeable the Specifier and End Buyer are
will affect the price. This is an advantage when about stone maintenance, the longer and
cost is important, for there is always the happier all parties will be in giving the Owner
possibility to select alternatives offering a quality finished job that will last for years to
essentially the same desired characteristics. come.
Availability is important to check to determine
whether the stone is still quarried, is available 9.2 Sealers. If sealers are to be used, have
in the quantity required, and in the time frame the stone tested to ensure in writing the
of installation of the project. Sometimes the sealer’s performance for the stone and
more limited the availability, the higher the application of the stone intended. New surface
cost. If the stone is only available from one and penetrating sealers are becoming available
company, the Producer can demand a very high on the market every year.
price and the Specifier should be made aware
of this. 9.3 Maintenance and Cost. The
maintenance issues for a specific stone and the
8.6 Other factors affecting the cost on cost attributed to it can vary from one type to
large projects may include: another, and may impact the decision to use
that stone in a particular application.
8.6.1 Quantity allowed for storage or attic
material. MIA Bookstore Resources:
Reprints of this chapter, along with the Stone
8.6.2 Extra material needed in the event of Testing chapter, can be purchased in a separate
damages, improperly fabricated material, or publication from the MIA Bookstore. The “Stone
other reasons replacement material might be Selection & Stone Testing” technical module
needed. includes the contents of both chapters and
additional illustrations and pictures.
Two MIA-produced, consumer-focused brochures
8.6.3 Determination of who will pay taxes
are available on the use and care of natural stone:
may be an issue and should be clarified. “Beautify Your Home with Natural Stone (A Guide
to Choosing Natural Stone and a Qualified Stone
8.6.4 Availability of a storage facility at the Contractor),” and “Care & Cleaning of Natural
jobsite that is of adequate size to properly and Stone Surfaces.” Stone professionals can purchase
securely store material until job is complete. both of these brochures from the MIA Bookstore.

8.6.5 Consult with your local MIA Member to

review these and other costs that factor into the
overall project budget.

9.0 MAINTENANCE
9.1 General. Maintenance of the stone
after it is installed is commonly forgotten. The

Page 3-8 • Dimension Stone Selection  2016 Marble Institute of America

Stone Testing slicing the stone thin with an ultraprecision,
thin-blade diamond saw. The stone slice on a
slide is then precision-ground to a precise
1.0 INTRODUCTION thickness of about 20 to 30 microns. At that
thickness most minerals, regardless of color,
1.1 General. Testing evaluates the are translucent and can be studied under a
suitability of a specific stone for a particular microscope. In this way minerals can be
application. The strength of the stone is tested identified, the crystal or fragment boundaries
to determine its resistance to crushing and can be evaluated, and incipient microfractures
bending. The density, or specific gravity, is can be seen, as can any chemical degradation
tested to design a support system capable of that may weaken stone, permit water entry, or
carrying the weight of the stone. The amount allow unanticipated breakup.
of water the stone will absorb (absorption rate)
will help determine the resistance of the stone 1.3.2 Exact identification of the minerals by
to staining and freezing. The stone’s wear thin section is a subjective, experience-based
resistance and slip resistance are crucial in skill and is largely being replaced by exact
flooring applications. methods of chemical analysis. Having both the
thin section and chemical analysis is the
1.2 ASTM tests, many of which are preferred procedure, as the physical features
conducted within engineering parameters, do can be seen documented on known mineral
not include petrographic and other geologic crystals or grains.
tests useful to evaluating stone behavior
through time in adverse environmental 1.4 X-ray diffraction (XRD) analysis is
settings. If and when a failure occurs, questions one of the tried-and-true analytical techniques
about what went wrong and why are asked; used for decades in petrology and remains the
however, test data reviewed frequently may preferred technique in certain situations.
not reveal information useful to answer these However, more modern analytical techniques
questions. Stone behavior is directly related to have evolved that are far more precise, analyze
the behavior of the mineral or minerals that
far more compounds and elements, and are
make up the stone. Knowing something about rapidly replacing XRD for most routine
physical and chemical characteristics of the purposes.
common minerals found in stone can be very
useful in understanding its behavior. 1.5 Lithogeochemistry, the chemical
analysis of stone, relies on many new
1.3 Petrography is the science of procedures too numerous to attempt
description and classification of rocks. A explanation here. The following are just a few
petrograpic analysis can be arranged through notable lithogeochemical analysis procedures:
most construction material laboratories. A
comprehensive petrographic analysis will often 1.5.1 Instrumental Neutron Activation
suffice to answer many behavioral questions. Analysis (INAA)
Other, more sophisticated analyses performed
in well-equipped chemical laboratories to 1.5.2 Atomic Absorption Spectroscopy (AA)
determine exact chemical and trace element
content can also be useful. 1.5.3 Inductively Coupled Plasma Emission
Spectroscopy (ICP-OES)
1.3.1 Perhaps the most common and time-
tested petrologic studies use thin sections of 1.5.4 X-ray Fluorescence Spectroscopy (XFS)
stone. These are prepared by polishing small
samples very flat, gluing them to glass
microscope slides (1" x 3" to 2" x 3"), and

 2016 Marble Institute of America Stone Testing • Page 4-1

1.5.5 Inductively Coupled Plasma Emission formally reaffirmed without change in 1994.
Mass Spectrometry (ICP-MS) The latest edition should be used. Copies of
ASTM standards can be obtained from ASTM
1.5.6 A few grams of a stone can be International, 100 Barr Harbor Drive, West
qualitatively and quantitatively analyzed Conshohocken, Pennsylvania 19428-2959
accurately for bulk stone chemical content plus U.S.A. Telephone 610.832.9585. Copies can
more than 53 trace elements–some to also be ordered through ASTM’s web site and
fractional parts per billion. downloaded electronically. The Internet
address is www.astm.org.
1.5.7 Although the ASTM Committee on
Stone, C-18, has yet to include petrologic tests 2.3 ASTM Standard Specifications. In
in their repertoire, lithogeochemistry is addition to the standard test methods, ASTM
already quality-standardized by the has developed a series of standard specifications
International Organization for Standardization prescribing the minimum performance of each
(ISO). ISO/IEC Guide 25 is an accreditation kind of stone when tested in accordance with
that many laboratories have because of the the standard test methods. The ASTM
importance of these studies in the global Standards and Specifications are listed in
mineral-extraction industries. Chapter 2.

2.0 ASTM STANDARD TEST 2.3.1 These specifications are the standard
METHODS AND methods for determining the characteristics of
building stone needed for proper design for a
SPECIFICATIONS
particular application. They should be
performed with care and the results used with
2.1 ASTM International, formerly
an understanding of their intent and
known as the American Society for Testing and
limitations. An independent testing laboratory
Materials, has developed several standard test
properly equipped and capable of performing
methods to evaluate stone characteristics so
the tests should perform all tests. Stone
that stones can be compared on a uniform basis.
Producers or Distributors, Associations, and
The Marble Institute of America recommends
other Promotional Organizations may publish
ASTM methods and standards for dimension
typical test values. While these values can serve
stone as guidelines for specification and
as a guide, current tests should be conducted
installation. ASTM International is the world’s
on the actual stone to be used for a particular
largest voluntary standards development
project.
organization. Note that stone testing according
to European methods and conditions may use
2.4 Review for Suitability. ASTM test
different procedures that give different results
results for various stones are guidelines and
than do ASTM methods for the same stone.
information on the stone characteristics. In
This is particularly true of tests for abrasion
many cases, an Engineer should be employed
(wear). The ASTM Standard Test Methods are
to review the results of the test data and
listed in Chapter 2.
compare with actual installation methods to
determine if the stone is suitable for the
2.2 Current Standards. ASTM standards
application in the specified thickness suggested,
are revised from time to time. A revised
and if not, what changes should be employed to
version is indicated with a hyphen followed by
make the stone work as intended for the job in
a two-digit number after the basic designation
question. Evaluation and/or testing of
of the standard, e.g., ASTM C119-11, showing
compatibility of grouts, sealers, setting
that it was revised in 2011. An additional
methods, and anchoring must be performed
number in parentheses, e.g., ASTM C97-
along with the stone.
92(1994), indicates that the 1992 edition was

Page 4-2 • Stone Testing  2016 Marble Institute of America

3.0 OVERVIEW OF STANDARD sedimentary stone such as slate, than in a stone
TEST METHODS with a less definite rift, such as some igneous
stones. The variation also depends on how
3.1 Stone Uniformity. Stone is a product strongly the layers are cemented or adhered to
of nature, and as such, it varies. The properties each other. To determine the variation,
of stone from one part of a quarry may not be strength tests are conducted with the load
truly representative of the same stone from a parallel and perpendicular to the rift. For
different part of the quarry. Some Architects general information only one direction is
specify strength-testing specimens from each tested, but the Specifying Authority may
quarry block to verify sufficient uniformity for specify testing in both directions to ensure that
the application. At the very least, current test the stone strength is adequate for the
results should be used because they are more application. When specimens are submitted for
apt to reflect the stone currently being such testing, it is important that the rift be
quarried. clearly marked. The strength tests can be
conducted by four conditions, wet or dry, and
3.2 Wet/Dry Testing. For most tests, the with the load parallel or perpendicular to the
stone specimens are tested dry. However, rift.
since the strength may vary when the stone is
wet, the strength tests (i.e. compressive 3.4 Horizontal Applications. ASTM
strength, flexural strength, modulus of C99, Standard Test Method for Modulus of
rupture) are sometimes performed using wet Rupture of Dimension Stone, ASTM C170,
stone specimens. For the dry condition, the Standard Test Method for Compressive
stone specimens are dried in an oven at 60°C Strength of Dimension Stone, and ASTM
±2°C (140°F ±2°F) for at least 48 hours or C880, Standard Test Method for Flexural
until the weight does not change with Strength of Dimension Stone test results are
additional drying. For the wet condition, the not suitable to use for horizontal (floor)
stone specimens are soaked in water at 22°C applications where the thickness of the stone
±2°C (72°F ±2°F) for 48 hours, wiped, and tile being used is less than 1¼".
immediately tested. For general “catalog type”
information, the stone is usually tested in a dry 3.5 Limitations of Thin Stone Pavers.
condition. The Specifying Authority may It is the position of the Marble Institute of
specify additional wet testing for a particular America that stones less than 1¼", when used
project to ensure that the stone will have for paving, do not possess any structural
adequate strength for the application. qualities other than abrasion resistance. The
flexural, compressive, and breaking strengths
3.3 Testing Parallel/Perpendicular these thin stones have will not materially
with the Rift. The strength of stone also improve the engineering quality of the
varies with the relation of the load or force to designed surface. These thin stones are
the direction of the “rift” of the stone. The rift furnished for their aesthetic appearance and to
is the plane of easiest splitting of the stone. supply abrasion resistance only.
Consider that a block of stone is like a deck of
cards with rift direction corresponding to the
plane of the cards. The cards are like the layers
of the stone. The stone will be weaker if the
applied loads tend to make the cards (layers)
slide against each other than if the load is
applied to squeeze the cards against each other.
The variation in strength is likely to be greater
in a stone with a more pronounced rift, like a

 2016 Marble Institute of America Stone Testing • Page 4-3

4.0 ABSORPTION AND BULK 4.3 Slate. The water absorption test for
SPECIFIC GRAVITY TESTING OF slate, ASTM C121, uses different-size
specimens. They should be 4" square and the
DIMENSION STONE
“as cleft” thickness, which is typically ¼" to
3/8". Otherwise, the procedure is the same.
4.1 Water absorption is a measure of the
porosity of a stone and can be an indicator of its
4.4 Stone Density. The density of the
susceptibility to damage during freezing. A
stone indicates the unit weight of the stone,
stone that has greater water absorption will
which is necessary for the Architect or
also tend to absorb liquid stains more readily.
Engineer who is designing the structure to
In general, the lowest water absorption is
support the stone. The standard specifications
desired. The absorption is expressed as the
prescribe minimum densities. The minimum
percent weight change due to absorbed water.
densities are used to classify stones. For
The maximum allowable water absorption for
example, there are three classes of limestone,
each type of stone is prescribed in the standard
with each class having a different density as well
specifications for that specific stone. The
as different strength requirements. Generally,
required values range from 0.20% for marble
a higher-density stone is probably harder, less
to 12% for low-density limestone. According
porous, and stronger, but this is not always the
to ASTM C97, at least 3 specimens, as
case. Note that there is no density for slate
described for the density determination, are
specified in ASTM C629, although it could be
dried and weighed. It is important that the
determined, if desired, using the procedure of
surface not be fractured by the cutting process
ASTM C97.
because these fractures will increase water
absorption. The specimens are then soaked in
4.5 Specific Gravity is the ratio of the
water for 48 hours, wiped dry, and weighed
density of the stone to the density of water. If
again. The difference in weights is divided by
a stone has a specific gravity of 2.6, it is 2.6
the dry weight and multiplied by 100 to give
times as heavy as water. Density is expressed as
the percentage of water absorption. Variations
pounds per cubic foot (lb/ft3) or kilograms per
in the wiping of the wet specimen before
cubic meter (kg/m3). The density in lb/ft3 can
weighing will cause variations in the result. The
be determined by multiplying the specific
standard test method describes removing the
gravity by 62.4 (the weight of 1 cubic foot of
specimens from the water and surface drying
water) or by multiplying by 1000 for the
with a damp cloth, but this is still somewhat
density in kg/m3. One lb/ft3 equals 16.02
subjective. A dryer wet specimen will result in
kg/m3. The specific gravity is the same in both
a lower absorption number.
measurement systems.
4.2 Specimen Thickness. This standard
4.6 Stone Dry and Wet Weights. The
requires that the specimens have minimum
dry weight of the stone specimen is divided by
dimensions of 2 inches. However, sometimes
the volume. The specimen should be a cube,
the stone is not available in that thickness,
cylinder, or other regular solid with the
especially flooring material, which may be only
dimensions between 2 and 3 inches. The
3/4" or 3/8". Depending on the porosity of
surface should be reasonably smooth, e.g.,
the stone, testing these thinner specimens may
saw, core drill or better, but no chisels or tools
result in an “apparent” water absorption higher
which tend to fracture the stone. At least 3
than if the standard-sized specimens were used.
specimens should be tested and the results
During the soaking, water may not be absorbed
averaged. The dry weight of each specimen is
to the center of the standard specimen, but
determined after drying 48 hours. The stone is
water might be absorbed to the center of the
then soaked in water for 48 hours, wiped
thinner specimens.
almost dry, and weighed. It is then suspended

Page 4-4 • Stone Testing  2016 Marble Institute of America

in water by fine wire and the suspended weight newton per square meter. Occasionally, the
is measured. The difference between the two strength is expressed as kilograms/square
weight measurements in grams is the volume in meter (kg/m2), which is technically incorrect
cubic centimeters (one cubic centimeter of because the kilogram is a unit of mass while the
water has a mass of 1 gram). The dry weight in newton is a unit of force (or weight). In the
grams divided by the volume in cubic U.S. system, we tend to think of mass and
centimeters is the specific gravity. The specific weight interchangeably. Therefore, when a
gravity is multiplied by 62.4 to obtain the weight or force is intended, the term used is
density in lb/ft3. Subtracting a tare weight of pound force (lbf).
the suspended wire in water provides a
correction for the mass of the fine wire. The following conversions can be used:
1 lbf/in2(psi) = 6,895 pascals (Pa)
4.6.1 This method of measuring the volume is 1 lbf/in2 (psi) = 4.882 kilograms/square
based on the principle that a body suspended in meter (kg/m2)
water has an apparent weight loss equal to the 1 kg/m2 = 9.807 Pa
volume of water displaced. In the metric The terms kilopascal (kPa) and megapascal
system, the 1 cubic centimeter of water has a (MPa) are used for 1,000 Pa and 1,000,000 Pa,
weight of 1 gram. In other words, there is a respectively.
buoyant force on the object equal to the weight
of the water displaced. 5.3 Compressive Strength of
Dimension Stone. Compressive strength is a
5.0 STRENGTH TESTING OF measure of the resistance to crushing loads. If
DIMENSION STONE one were to build a stone wall, for example,
the stone at the bottom would have to
5.1 Compressive Loads and Strength. withstand the compressive load of the weight
The loads on a material such as stone are of the stones above. A stone floor must be able
expressed as the applied force divided by the to bear the crushing loads of people, furniture,
area which must bear the material. For and other objects on the floor. The
example, the compressive (crushing) load on a compressive strength is the maximum load per
floor caused by a flat-bottomed round planter unit area that the stone can bear without
is the weight of the planter (including the soil crushing. A higher compressive strength
and plants) divided by the area of the bottom of indicates that the stone can withstand a higher
the planter. The compressive strength of the crushing load. The required values range from
floor is the maximum compressive load the 1,800 psi (12.45 MPa) for marble to 19,000 psi
floor material can bear without crushing or (131 MPa) for granite. To determine the
deforming more than is allowed. In practice, compressive strength, at least 5 specimens are
the allowable loads in actual use are less than tested in ASTM 170. They should be cubes at
the maximum loads that a material can least 2" to 3" on each side. Each face must be
withstand during testing, to provide a safety perfectly flat and they must be parallel or
factor. In all structural design, the maximum perpendicular with each other. Faces must be
material strengths are reduced by a safety smooth with no tool marks and there should be
factor to establish the allowable design no nicks at the corners. The faces must be
strengths. The safety factor allows for honed or polished with no saw marks or other
variations in the material strength, possible tool marks remaining. Any flaws in the
overloads in use, and similar considerations. specimens can result in a lower compressive
strength. In some instances, the testing
5.2 Strength Units of Measure. The laboratory may have to refinish the specimens
strengths are expressed as pounds/square inch to produce surfaces sufficiently flat for testing.
(psi) or pascals (Pa). A pascal is a force of 1

 2016 Marble Institute of America Stone Testing • Page 4-5

5.3.1 The compressive strength can be there should be no nicks at the corners. The
determined in the dry or wet condition and faces should be honed or polished with no saw
with the load parallel or perpendicular to the marks or other tool marks remaining. Any
rift. For the dry and wet conditions, the flaws in the specimens can result in an apparent
specimens are dried or soaked for 48 hours as low modulus of rupture strength. The flexural
described in the density test. For the (bending) strength may be tested in a dry or
compressive strength testing, the specimen is wet condition and with the load parallel or
placed on the flat plate of the testing machine perpendicular to the rift. The specimens must
and increasing loads are applied to the top of be dried or soaked for 48 hours. For the
the specimen through another flat plate. The modulus of rupture test, the stone specimen is
test apparatus allows the top plate to swivel on laid flat on two crosswise parallel steel edges 7"
a ball joint to adjust for any slight slope on the apart. The 7" span allows the 8" long specimen
top of the specimen. The rift of the specimens to overhang the supports by ½” at each end.
should be vertical for the load to be parallel to The supports of the fixture are gimbaled to
the rift, or horizontal for the load to be accommodate any warp of the test specimen
perpendicular to the rift. and prevent the introduction of torsional
stresses applied to the stone. The test load, or
5.4 Bending Strength. The tests for force, is applied to the center of the top of the
modulus of rupture, ASTM C99 and ASTM specimen through another crosswise edge. The
C120 (Slate), and for flexural strength, ASTM load is increased until the specimen breaks.
C880, determine the strength of the stone in The flexural strength is then calculated from a
bending. A stone or door lintel must resist the formula based on the geometry of the test
bending loads from the weight of the stone. A condition.
veneer must bear bending loads, between
anchor points, from exterior wind loads or 5.5.1 If the specimens are to be tested with the
persons leaning against interior veneers. Floor load perpendicular to the rift, then the rift
stone must bridge possible gaps in the grout or plane must be parallel to the 4" x 8" faces.
thin-set support. For all three tests, the stone Returning to the card deck analogy, the “deck”
specimens are supported near the ends and a of the specimen must be placed flat on the
downward load applied to the top. The supports. If the specimens are to be tested with
modulus of rupture tests, ASTM C99 and the load parallel to the rift, the plane of the rift
ASTM C120, prescribe applying the load to a must be parallel to the 2¼" x 4" ends of the
single point at mid-span. The flexural strength specimen. In the analogy, several decks would
test, ASTM C880, prescribes applying the load have to be stacked up to a height corresponding
simultaneously to two points, each one quarter to the 8" specimen length, and the card stack
of the span from the end support. The flexural or specimen would be placed so the cards are
strength is expressed as lb/in2 or Pa. A higher on edge with each card parallel to the
flexural strength or modulus of rupture supporting edges. This is illustrated in ASTM
indicates a higher bending strength. The C99.
required minimum values range from 400 psi
(2.8 MPa) for low-density limestone to 10.3 5.5.2 In general, the flexural strength with the
MPa for granite. load parallel to the rift will be less than that
with the load perpendicular to the rift. The
5.5 Modulus of Rupture of Dimension variation would be greater for a stone with a
Stone. ASTM C99 requires a minimum of 3 more pronounced rift than for a stone with a
specimens that are 4"x 8"x 2¼" thick. All of rift less distinct.
the faces, except the ends, must be flat and be
parallel or perpendicular with each other. The
faces must be smooth with no tool marks and

Page 4-6 • Stone Testing  2016 Marble Institute of America

5.6 Flexure Testing of Slate. The nicks at the corners. Faces should be honed or
modulus of rupture testing for slate, specified polished with no saw marks or other tool marks
in ASTM C120, is somewhat different than remaining. Any flaws in the specimens can
C99. The specimens are 12" x 1½" x 1" thick. result in a lower flexural strength. Since the
Rubbing or sanding the cleft faces achieves the length of the specimens serves only to provide
specified 1" thickness. Six specimens are sufficient overhang, exact length is not critical
required: 3 with length parallel to the rift, and to the results.
3 with length perpendicular to the rift. For the
test, the span between the supporting knife 5.7.1 The second difference that distinguishes
edges is 10". the ASTM C880 flexural strength test from the
modulus of rupture tests is that the flexural
While these test methods are useful, they have strength test is conducted with quarter-point
certain limitations. Since the specimen for loading. That is, the test load on the top of the
ASTM C99 is always 2¼" thick (or 1" for specimen is not applied to a single location at
ASTM C120), the test does not indicate any midspan, but rather, the total test load is split,
reduction in the strength for thinner stone with half of the load applied at each of two
when used as a veneer or for flooring. They are points one quarter of the span from the
valid for thicker sections. Because of the supports, In this way, the entire center half of
midspan loading, any weakness that is not in the specimen is subjected to the same
the center third (approximately) of the maximum bending forces. Thus any local
specimen will usually not affect the strength weakness, as from a vein, is more likely to be
value determined by the test. These limitations reflected in the resulting flexural (bending)
are overcome by the flexural strength test of strength.
ASTM C880.
5.7.2 The flexural strength test can be
5.7 Flexure Testing of Dimension performed in the dry or wet condition and with
Stone. The flexural strength test of ASTM the load parallel or perpendicular to the rift.
C880 is similar to the modulus of rupture tests, The stone specimens are dried, or are soaked
with two significant differences. First, the in water, for 48 hours. The rift directions are
stone is tested at the thickness at which it will the same as described for the modulus of
be used. The test span is proportional to that rupture test. At least 5 specimens are tested for
thickness by a ratio of 10:1. Thus any reduction each condition, and the results averaged.
in the bending strength due to the stone
structure, e.g., grain size, grain cementing, 5.7.3 As in the modulus of rupture test, the
etc., will be reflected in the test results. The load is increased until the specimen breaks.
test span is 10 times the thickness, but the Then the flexural strength is calculated using a
actual length of the specimens should be about formula based on the geometry of the test
12 times the thickness to allow for some conditions.
overhang. The width is 1½ times the thickness,
but, if the thickness is less than 2.67", the 5.8 Flooring Applications. There are
width is 4". If specimens for an exterior two additional considerations for stone used
building veneer are 4" x 1¼" x 15", the test for flooring: the wear or abrasion resistance, as
span should be 12.5. For a 3/8" floor tile, the measured by ASTM C241, and slip resistance
specimens would be 4" x 3/8" x 4½" and the as measured by its coefficient of friction,
test span would be 3.75". As for modulus of formerly evaluated according to ASTM C1028.
rupture specimens, all faces, except the ends, This test method was withdrawn in 2014 and
must be flat and be parallel or perpendicular no replacement method was offered. See
with each other. The faces must be smooth section 5.11, below, for an explanation.
with no tool marks, and there should be no

 2016 Marble Institute of America Stone Testing • Page 4-7

5.9 Abrasion Resistance of Stone weighed. Knowing the dry weight of the
Subjected to Foot Traffic. Wear resistance specimens, they are soaked in water for at least
is an essential characteristic that will determine 1 hour, and a bulk density is determined in the
whether a stone is suitable for use as a floor. same way as the density procedure of ASTM
The abrasion test of ASTM C241 results in an C97. However, the abrasion specimen is
index number proportional to the volume of thinner than that required by ASTM C97 and
material abraded or worn off the stone during the specimen is not soaked for 48 hours.
the test. The abrasion index numbers are scaled Consequently, the density may not be exactly
to generally range between 0 and 100. The the same as determined by ASTM C97.
ASTM specifications for stone list a minimum
abrasion index for each type of stone. Marble 5.10 The abrasion resistance index,
and limestone, for example, should have an which is proportional to the volume abraded,
index of at least 10 (12 in heavy traffic areas); is calculated for each specimen using the
quartzitic sandstone and slate should have an average weight (before and after abrading), the
index of 8; and granite, 25. weight loss, and the apparent density. An
abrasion resistance index will usually be in a
5.9.1 During the test, the weight loss of stone numeric value less than 100, but not always.
specimens is measured before and after being
abraded, and then the density of the specimen 5.10.1 There are two concerns regarding
is determined. The abrasion index is calculated this test method. First, it is not always possible
using the average weight, the abrasion weight to obtain specimens that are 1" thick. Although
loss, and the density. the ASTM method does not indicate it,
specimens of other thicknesses can be
5.9.2 The test requires 3 specimens, 2" square determined by adjusting the 2,000-gram load
and 1" thick. One 2" square face should have on the specimen so that the load on the bottom
the finish to be evaluated, e.g., polished, of the specimen, the abrading face, is the same
honed, etc. The others may have saw marks, as it would be if the specimen were actually 1"
but should not be cut in a manner that fractures thick. For a specimen ¾" thick, the 2,000
the stone because the fractures would affect the grams would be increased by the mass of the
density determination. missing ¼" thickness of the specimen.

5.9.3 The stones are abraded using a machine 5.10.2 The second concern is the abrasive.
developed by Kessler. The machine includes a ASTM C97 specifies a particular abrasive that
horizontal, round, cast iron “lap” about 9" in is no longer being produced. The ASTM
diameter, which rotates at a speed of 45 committee is currently conducting round-
revolutions per minute (rpm). The specimens robin tests among different laboratories to
are mounted in a holder that rotates in the same determine a possible correction factor or a
direction as the lap, but at a different speed. different test method which will produce
While the lap and the specimen rotate, an abrasion index numbers that are the same as
abrasive flows onto the lap to abrade the from the methods of ASTM C241, so that new
bottom of the specimens. Each specimen test results can be compared with earlier
supports a load of 2,000 grams, which includes results. In the meantime, test laboratories have
the weight of the specimen holder, but not the had to develop a correction factor by
specimen itself. comparing the results for stones having
different abrasion resistances, e.g., soft and
5.9.4 For the test, the stones are dried for medium marble and granite, using the old and
48 hours and weighed. The specimens are then currently available abrasives.
abraded in the Kessler machine for 5 minutes
(225 revolutions at 45 rpm), dusted off, and

Page 4-8 • Stone Testing  2016 Marble Institute of America

5.11 Coefficient of Friction Testing. the overall design of the building, and
Slippery floors are a safety hazard, thus some terminologies relating to these are available
measure of slip resistance is needed to evaluate from ASTM under C717, and specific tests are
stone and its finish as a floor material. also available.
Traditionally in the stone industry, slip
resistance was evaluated by measuring the 5.12.3 Considerations for testing and
static coefficient of friction (the force required evaluating stone must include petrographic and
to initiate slipping divided by the normal force) mineralogical data. The use of stone can be a
per the ASTM C1028 method. This test factor directly related to whether it is an
method was withdrawn in 2014 and no igneous rock like granite, a sedimentary rock
replacement method was offered. like limestone, or a metamorphic rock like
marble. The petrographic information may
In the ceramic tile industry, slip resistance is indicate a stone’s elastic condition to change,
not being evaluated by measuring the dynamic or absorption degrees, or determine its
coefficient of friction (the force required to strength and durability, as does the mineral
sustain slipping divided by the normal force) content of the stone. The mineralogical
per the ANSI A137 method. information is important to see if the stone
contains any minerals that may cause rust (as
The Marble Institute of America has several with stones containing ferrous minerals),
studies using the ANSI A137 method on exfoliation like some carbon stones, or
Natural Stones. Recorded results are minerals that may decompose and change due
encouraging, indicating that this test method to weather conditions. The silicates in granite
may be equally reliable for use with natural weather better than the carbonates of marble
stone products as it is with ceramic products. or limestones. The performance of a stone is
Additional studies are yet to be completed related to its composition, and this is why some
which will provide greater statistical stones are more brittle than others, and why
confidence, after which a formal endorsement some stones, like common limestone, become
of the procedure will likely follow, however harder when exposed to air through a process
that endorsement was not yet available at the called “curing.”
time of this writing. Such endorsement will be
published as a Marble Institute of America 5.12.4 In designing stone exterior facades,
Technical Bulletin, and the reader is advised to consider the environmental conditions: rain,
check the Marble Institute of America’s snow, hail, freezing and high temperature
technical publications library to see the most variations, and others. The stone must be
recent publications on the subject. resistant to weathering and decay. Carbon
monoxide, sulfates, and other atmospheric
pollutants form an acid, and with rainwater,
5.12 Other Stone Selection can corrode certain stones over the course of
Considerations. time.

5.12.1 Other considerations for selecting

exterior stones are the freeze/thaw capabilities
of the stone in extreme climates. Also, the
effect of ultraviolet light on the fading or
changing of color of certain dimension stones.
Tests are available for these considerations.

5.12.2 Sealants, seals, and gaskets for

exterior applications are also considerations in

 2016 Marble Institute of America Stone Testing • Page 4-9

6.0 OTHER ASSOCIATIONS FOR
ADDITIONAL INFORMATION

American Geosciences Institute (AGI)

www.agi-usa.org
American Society of Civil Engineers
(ASCE)
www.asce.org
American Concrete Institute (ACI)
www.concrete.org
American Institute of Steel
Construction (AISC)
www.aisc.org
American Iron and Steel Institute (AISI)
www.steel.org
Construction Specifications Institute
(CSI)
www.csinet.org
International Masonry Institute (IMI)
www.imiweb.org
Masonry Institute of America (MIA)
www.masonryinstitute.org
National Tile Contractors Association
(NTCA)
www.tile-assn.com
National Association of Architectural
Metal Manufacturers (NAAMM)
www.naamm.org
Precast/Prestressed Concrete Institute
(PCI)
www.pci.org
Tile Council of North America (TCNA)
www.tcnatile.com
Special Note: A worldwide directory of
ASTM-approved testing laboratories is
available from ASTM International.

MIA Bookstore Resources:

Reprints of this chapter, along with the Dimension
Stone Selection chapter, can be purchased in a
separate publication from the MIA Bookstore. The
“Stone Selection & Stone Testing” technical module
includes the contents of both chapters and
additional illustrations and pictures.

Page 4-10 • Stone Testing  2016 Marble Institute of America

GRANITE 1.2.2.9 C270, Standard Specification for
Mortar for Unit Masonry
1.0 GENERAL 1.2.2.10 C295, Standard Guide for
Petrographic Examination of Aggregates for
1.1 Related Documents Concrete
1.1.1 Drawings and general provisions, 1.2.2.11 C880, Standard Test Method for
including General and Supplementary Flexural Strength of Dimension Stone
Conditions of the Contract and Division I
Specification sections, apply to this section. 1.2.2.12 C1201, Standard Test Method for
Structural Performance of Exterior Dimension
1.2 Applicable Publications Stone Cladding Systems by Uniform Static Air
Pressure Difference
1.2.1 The following publications listed here
and referred to thereafter by alphanumeric 1.2.2.13 C1242, Standard Guide for
code designation only, form a part of this Selection, Design, and Installation of Exterior
specification to the extent indicated by the Dimension Stone Anchors and Anchoring
references thereto: Systems

1.2.2 ASTM International (ASTM): 1.2.2.14 C1352, Standard Test Method for
Flexural Modulus of Elasticity of Dimension
1.2.2.1 C615, Standard Specification for Stone
Granite Dimension Stone
1.2.2.15 C1353, Standard Test Method for
1.2.2.2 A666, Standard Specification for Abrasion Resistance of Dimension Stone
Annealed or Cold-Worked Austenitic Stainless Subjected to Foot Traffic Using a Rotary
Steel Sheet, Strip, Plate, and Flat Bar Platform Abraser

1.2.2.3 B221, Standard Specification for 1.2.2.16 C1354, Standard Test Method for
Aluminum and Aluminum-Alloy Extruded Strength of Individual Stone Anchorages in
Bars, Rods, Wire, Profiles, and Tubes Dimension Stone

1.2.2.4 C97, Standard Test Methods for 1.2.2.17 C1515, Standard Guide for
Absorption and Bulk Specific Gravity of Cleaning of Exterior Dimension Stone,
Dimension Stone Vertical and Horizontal Surfaces, New or
Existing
1.2.2.5 C99, Standard Test Method for
Modulus of Rupture of Dimension Stone 1.2.2.18 C1528, Standard Guide for
Selection of Dimension Stone for Exterior Use
1.2.2.6 C119, Standard Terminology
Relating to Dimension Stone 1.2.2.19 C1721, Standard Guide for
Petrographic Examination of Dimension Stone
1.2.2.7 C170, Standard Test Method for
Compressive Strength of Dimension Stone 1.2.2.20 C1722, Standard Guide for Repair
and Restoration of Dimension Stone
1.2.2.8 C241, Standard Test Method for
Abrasion Resistance of Stone Subjected to Foot
Traffic

 2016 Marble Institute of America Granite • Page 5-1

1.2.3 Marble Institute of America 1.6 Samples
(MIA):
1.6.1 The Granite Contractor shall submit
1.2.3.1 Membership, Products and Services through the General Contractor, for approval
Directory by the Specifying Authority, at least two sets of
samples of the various kinds of granite
1.2.3.2 Dimension Stone Design Manual specified. The sample size shall be 1'-0" x 1'-
0" minimum and shall represent approximately
1.2.3.3 Additional publications may be the finish, texture, and anticipated range of
available from the MIA Bookstore. Go online colors to be supplied. One set of approved
at www.marble-institute.com. samples shall be retained by the Specifying
Authority, and one set shall be returned to the
1.2.4 National Building Granite Granite Supplier for record and guidance. It is
Quarries Association (NBGQA) noted herein that granite is a natural material
and will have intrinsic variations in color,
1.2.4.1 Specifications for Architectural markings, and other characteristics.
Granite Depending on granite selected and quantity
required, a range mockup may be used to
1.3 Scope of Included Work further define the characteristics of the
material. Cost of mockup, if required, shall
1.3.1 The work to be completed under this not be included in this section.
contract includes all labor and materials
required for the furnishing and installation of 1.6.2 Prior to fabrication, an inspection and
all granite work shown or called for on the approval by the Specifying Authority and/or
contract drawings, specifications, and General Contractor and/or End User of the
addenda. finished slabs is recommended to understand
the finish and full range of the material.
1.4 Definition of Terms
1.7 Shop Drawings
1.4.1 The definitions of trade terms used in
this specification shall be those published by the 1.7.1 The Granite Contractor shall submit
MIA, NBGQA, or ASTM International. through the General Contractor, for approval
by the Specifying Authority, sufficient sets of
1.5 Source of Supply shop drawings, showing general layout,
jointing, anchoring, stone thickness, and other
1.5.1 All granite shall be obtained from pertinent information. These drawings shall
quarries having adequate capacity and facilities show all bedding, bonding, jointing, and
to meet the specified requirements, and from a anchoring details along with the net piece
firm equipped to process the material promptly dimensions of each granite unit. One copy of
on order and in strict accord with the approved shop drawings shall be retained
specifications. The Specifying Authority by the Specifying Authority, one copy shall be
(architect, designer, engineer, contracting retained by the General Contractor, and one
officer, end user, etc.) reserves the right to copy returned to the Granite Contractor for
approve the Material Supplier prior to the fabrication. NO FABRICATION OF
award of this contract. Stone and workmanship GRANITE SHALL BE STARTED UNTIL
quality shall be in accordance with Industry SUCH DRAWINGS HAVE BEEN FULLY
Standards and Practices as set forth by the MIA. APPROVED AND MARKED AS SUCH. The
Granite Contractor shall not be responsible for
determining, making, or verifying (1) design,

Page 5-2 • Granite  2016 Marble Institute of America

structural, wind, seismic, or other design 2.1.2.2 Provide information as in (1) for each
loads; (2) engineering estimates; (3) plans or different granite/finish combination in the
specifications; or (4) the types, sizes, or project.
locations of anchors, unless specifically added
to the scope of work. 2.1.3 Finishes: Finishes listed in the
schedule shall conform with definitions by
1.8 Defective Work MIA, NBGQA, or ASTM International.

1.8.1 Any piece of granite showing flaws or 2.2 Setting Mortar

imperfections upon receipt at the storage yard
or building site shall be referred to the 2.2.1 Mortar for setting shall be Type N, as
Specifying Authority for determination as to defined in ASTM C270, Standard Specification
responsibility and decision as to whether it shall for Mortar for Unit Masonry. All mixing,
be rejected, patched, or redressed for use. handling, and placing procedures shall be in
accordance with ASTM C270.
1.9 Repairing Damaged Stone
2.3 Pointing Mortar
1.9.1 Chips at the edges or corners may be
patched, provided the structural integrity of 2.3.1 Mortar for pointing shall be Type N,
the stone is not affected and the patch matches as defined in ASTM C270 (Standard
the color and finish of the natural stone so that Specification for Mortar for Unit Masonry).
it does not detract from the stone’s All mixing, handling, and placing procedures
appearance. shall be in accordance with ASTM C270.

2.0 MATERIALS 2.4 Sealants and Backup

Material (If Applicable)
2.1 Granite
2.4.1 Where specified, (state type or name of
2.1.1 General: All granite shall be of sealant) shall be used for the sealing of joints.
standard architectural grade, free of cracks, The backup material used with the sealant shall
seams, starts, or other traits which may impair be (identify material).
its structural integrity or function. Inherent
color variations characteristic of the quarry 2.5 Anchors, Cramps, and
from which it is obtained will be acceptable. Dowels
Texture and finish shall be within the range of
samples approved by the Specifying Authority. 2.5.1 All anchorage components shall be of
300 Series stainless steel (refer to ASTM A666)
2.1.1.2 ASTM C615 [C97] [C99] [C170] or aluminum (refer to ASTM B221) with
[C241] [C880] See the chart of applicable strength and durability properties meeting or
ASTM standards and tests in the Appendix. exceeding those of 6063-T6. Anchor types and
assemblies shall comply with ASTM C1242.
2.1.2 Schedule: Granite shall be provided Reliance on adhesives alone for material
as follows: attachment will not be permitted.
2.1.2.1 For (state location on building) (state
name and color) granite with a (type) finish,
supplied by (name company or list several approved
suppliers).

 2016 Marble Institute of America Granite • Page 5-3

3.0 FABRICATION 3.5 Cutting for Anchoring,
Supporting, and Lifting Devices
3.1 Beds and Joints
3.5.1 Holes and sinkages shall be cut in
3.1.1 Bed and joint width shall be stones for all anchors, cramps, dowels, and
determined by analysis of anticipated building other tieback and support devices per industry
movements and designed to accommodate standard practice or approved shop drawings.
such movements without inducing undue However, additional anchor holes may be
stresses in the stone panels or joint filler drilled at job site by Granite Contractor to
materials. Expansion joints shall be designed facilitate alignment.
and located to accommodate larger
movements. 3.5.2 No holes or sinkages will be provided
for Granite Contractor's handling devices
3.2 Backs of Pieces unless arrangement for this service is made by
the Granite Contractor with the Granite
3.2.1 Backs of pieces shall be sawn or Fabricator.
roughly dressed to approximately true planes.
Back surfaces shall be free of any matter that (NOTE: It is not recommended that lewis pins
may create staining. be used for stones less than 3½" thick.)

3.3 Moldings, Washes, and 3.6 Cutting and Drilling for

Drips Other Trades

3.3.1 Moldings, washes, and drips shall be 3.6.1 Any miscellaneous cutting and drilling
constant in profile throughout their entire of stone necessary to accommodate other
length, in strict conformity with details shown trades will be done by the Granite Fabricator
on approved shop drawings. The finish quality only when necessary information is furnished
on these surfaces shall match the finish quality in time to be shown on the shop drawings and
of the flat surfaces on the building. details, and when work can be executed before
fabrication. Cutting and fitting, due to job site
3.4 Back-checking and Fitting conditions, will be the responsibility of the
Granite Contractor.
to Structure or Frame
3.6.2 Incidental cutting such as for window
3.4.1 Stone coming in contact with
frame clips, etc., which is normally not
structural work shall be back-checked as
considered to be the responsibility of the Stone
indicated on the approved shop drawings.
Supplier, will be provided only by arrangement
Stones resting on structural work shall have
by the General Contractor and Granite
beds shaped to fit the supports as required.
Contractor with the Granite Fabricator.
3.4.2 Maintain a minimum of 1" between
stone backs and adjacent structure. (Note: 3.7 Carving and Models
many bolted connections will require more
space than this; 2" space may be more 3.7.1 All carving shall be done by skilled
desirable. Large-scale details should illustrate Stone Carvers in a correct and artistic manner,
and control these conditions.) in strict accordance with the spirit and intent of
the approved shop drawing, or from models
furnished or approved by the Specifying
Authority.

Page 5-4 • Granite  2016 Marble Institute of America

4.0 SHIPPING AND HANDLING 5.1.3 Granite shall be free of any ice or frost
at time of installation. Salt shall not be used for
4.1 Packing and Loading the purpose of melting ice, frost, or snow on
the granite pieces. Adequate protection
4.1.1 Finished granite shall be carefully measures shall be taken to ensure that exposed
packed and loaded for shipment using all surfaces of the stone shall be kept free of
reasonable and customary precautions against mortar at all times.
damage in transit. No material which may
cause staining or discoloration shall be used for 5.2 Mortar Setting of Granite
blocking or packing. (See “6.2 Protection of
Finished Work” in this chapter.) 5.2.1 Clean base materials to remove dirt or
other foreign matter.
4.2 Site Storage
5.2.2 Saturate concrete substrate several
4.2.1 Upon receipt at the building site, stone hours prior to setting granite. Prepare and
shall remain in the factory-prepared bundles place mortar in accordance with ASTM C270.
until beginning of the installation. Bundles Thoroughly wet stones prior to setting in
shall be staged in an area which is least mortar bed. Apply neat cement parge of
susceptible to damage from ongoing approximate 1/16" thickness to granite units
construction activity. Once unbundled, the prior to placing on mortar bed. Tamp stones
granite shall be stacked on timber or platforms into place using a rubber or plastic mallet to
at least 2" above the ground, and the utmost obtain full contact with the setting bed and
care shall be taken to prevent staining or proper stone unit alignment.
impact damage of the granite. If storage is to be
prolonged, polyethylene or other suitable, 5.3 Mortar Joints
nonstaining film shall be placed between any
wood and finished surfaces of the granite. 5.3.1 Mortar joints shall be raked out to a
depth of ½" to ¾". Apply pointing mortar in
4.2.2 Any holes or slots in the granite which layers not exceeding 3/8" and allow each layer
are capable of collecting water shall be to get hard to the touch before the next layer is
temporarily covered or plugged to prevent applied. Tool finished joints with a concave
freezing of collected water. Such covers or tool having a diameter approximately 1/8"
plugs are to be removed immediately prior to greater than the joint width.
installation of the piece.
5.3.2 Care shall be taken to keep expansion
5.0 INSTALLATION joints free of mortar, which would
compromise their function.
5.1 General Installation
5.4 Anchorage
5.1.1 Installation shall be accomplished with
competent, experienced Stone Setters, in 5.4.1 All granite shall be anchored in
accordance with the approved shop drawings. accordance with the approved shop drawings.

5.1.2 All granite pieces shall be identified 5.4.2 To the furthest extent possible, all
with a unique piece number corresponding anchor preparations in granite units shall be
with the number on the shop drawings. shop-applied.
Interchanging of numbered pieces is not
permitted. 5.4.3 All anchorage devices and anchor
hole/slot fillers shall be in accordance with

 2016 Marble Institute of America Granite • Page 5-5

ASTM C1242. Care must be taken to ensure 6.0 CLEANING AND
that any holes capable of retaining water are PROTECTION
filled after use to prevent water collection and
freezing.
6.1 Cleaning
5.5 Sealant Joints 6.1.1 Granite shall be cleaned after
installation and all pointing or caulking is
5.5.1 Where so specified, joints requiring complete. All dirt, excess mortar, weld
sealant shall be first filled with a closed-cell splatter, stains, and other defacements shall be
ethafoam rope backer rod. The backer rod removed.
shall be installed to a depth that provides
optimum sealant profile after tooling. 6.1.2 All cleaning methods shall be in
accordance with ASTM C1515.
5.5.2 If recommended by the Sealant
Manufacturer, primers shall be applied to the 6.2 Protection of Finished
substrate surfaces according to the
Work
manufacturer’s directions prior to application
of the joint sealant.
6.2.1 Granite installation in progress shall be
protected with film or fabric tarps secured over
5.6 Expansion Joints the work.
5.6.1 It is not the intent of this specification 6.2.2 After the granite is installed, it shall be
to make control or expansion-joint the responsibility of the General Contractor to
recommendations for a specific project. The properly and adequately protect it from
Specifying Authority must specify control or damage until all trades are finished. This
expansion joints and show locations and details responsibility includes the stone cleaning costs
on drawings. prior to the required final inspection. Where
lumber is required for protection, care should
5.7 Caulking be taken to protect the granite from staining by
the lumber, using plastic film or other suitable
5.7.1 Where so specified, joints shall be materials. Any fasteners used in construction
pointed with the sealant(s) specified in Section of temporary protection fixtures shall be
2.4 after first installing the specified backup corrosion resistant.
material and applying a primer if required, all
in strict accordance with the printed 6.2.3 Finishes commonly available are
instructions of the Sealant Manufacturer. defined as follows:

5.7.2 All sealants shall be tooled to ensure 6.2.3.1 Polished: Mirror gloss, with sharp
maximum adhesion to the contact surfaces. reflections.

5.8 Weep Tubes 6.2.3.2 Honed: Dull sheen, without

reflections.
5.8.1 Plastic or other weep tubes shall be
placed in joints where moisture may 6.2.3.3 Fine Rubbed: Smooth and free from
accumulate within the wall, such as at base of scratches; no sheen.
cavity, continuous angles, flashing, etc., or as
shown on architectural drawings. 6.2.3.4 Rubbed: Plain surface with
occasional slight “trails” or scratches.

Page 5-6 • Granite  2016 Marble Institute of America

6.2.3.5 Shot Ground: Plain surface with 6.2.3.13 Split Faced: Stone on which the
pronounced circular markings or “trails” having face has been broken to an approximate plane.
no regular pattern.
6.2.3.14 Rock (pitch) Faced: Similar to
6.2.3.6 Thermal (Flamed): Finish produced split faced, except that the face of the stone is
by application of high-temperature flame to the pitched to a given line and plane producing a
surface. Large surfaces may have shadow lines bold appearance rather than the comparatively
caused by overlapping of the torch. This finish straight face obtained in split face.
will vary in texture and depth between
different types of granite, as the finish is largely 6.2.3.15 Jet Washed: After certain
dependent upon the granite structure of the treatment finishes on stone, such as flaming, a
stone. high pressure jet wash can be used to assist in
cleaning the stone and bringing back more
6.2.3.7 Sandblasted, Coarse Stippled: color to the stone. Some producers have the
Coarse plain surface produced by blasting with machinery to use high pressure water with
an abrasive; coarseness varies with type of additives which gives a jet washed finish that
preparatory finish and grain structure of the looks like a flamed finish, yet maintains the
granite. color in the stone.

6.2.3.8 Sandblasted, Fine Stippled: Plain 6.2.4 Minimum Thickness: The

surface, slightly pebbled, with occasional slight suggested minimum thickness for all exterior
“trails” or scratches. veneer is as follows:

6.2.3.9 Bush-hammered, 8-cut: Fine bush- 6.2.4.1 Percussion produced finishes, such as
hammered finish, interrupted by parallel bush-hammered (sometimes referred to as a
markings not over 3/32" apart. A corrugated pointed finish), require a 1¼" thick slab
finish, smoother near arris lines and on small minimum to apply.
surfaces.
6.2.4.2 Other finishes can usually be applied to
6.2.3.10 Bush-hammered, 6-cut: any thickness slab, with the exception of some
Medium bush-hammered finish, similar to but granites not being able to withstand thermal
coarser than 8-cut, with markings not more finishing processes in thicknesses less than
than 1/8" apart. 1¼".

6.2.3.11 Bush-hammered, 4-cut: Coarse 6.2.4.3 Determination of proper stone

bush-hammered finish with same thickness must be evaluated using the following
characteristics as 6-cut, but with markings not criteria:
more than 7/32" apart.  Piece Size.
 Final Face Finish.
6.2.3.12 Sawn: Relatively plain surface
 Anchoring Detail.
with texture ranging from wire sawn (a close
approximation of a rubbed finish), to shot  Structural Design Load Requirements.
sawn, with scorings 3/32" in depth. Gang saws  Flexural Strength of the Granite.
produce parallel scorings; rotary or circular
saws make circular scorings. Shot-sawn 6.2.5 Minimum safety factors of 3 to 1
surfaces should be cleaned to remove all rust minimum on granite flexural stresses and 4 to
stains. 1 minimum on anchorage components in
granite are recommended.

 2016 Marble Institute of America Granite • Page 5-7

6.2.6 Ashlar or veneer used as a facing 1.2 The commercial stone industry,
requires a setting space of at least 1", as depending on the supplier or organization,
measured from the nominal thickness of the loosely accepts various granite-like stones
piece. under the label of “granite.” These include,
among others, banded or massive, nonbanded
6.2.7 Bed and Joint Width. The gneiss, and a few quartz-based stones. Such
minimum recommended bed and joint width is stones are marketed as “granitelike” or
¼" for exteriors and 1/8" for interiors. “granitoid,” though they are not true granite.1
Gneisses, high level metamorphic stone, are
6.2.8 Sawn backs. Because of physical included in the granite category by commercial
characteristics, most granites cannot be split to interests.
a thickness less than 1/3 of the lesser face
dimension. Consequently, sawn backs (see 3.4 1.3 The quartz-based stones are definitely
in this chapter) should be specified for most not granite, but rather the silica-cemented
veneers, and are frequently specified also for sedimentary stone quartzite or its
thicker ashlar, because of design metamorphic equivalent, orthoquartzite.
considerations. Quartzite, and especially orthoquartzite, have
a distinct cleft or cleavage at a mica-rich
6.2.9 Staining. Granite should be parting. Knowing the difference between true
protected from wet (green) wood, oils, mud, granite and granitelike stone helps the stone
construction waste, and asphalt compounds. industry professional to understand the
Contact Fabricator or Granite Contractor for physical properties, performance, and
proper remedies to staining problems that ultimately, the comparative quality of these
occur. natural materials.

1.4 Granite, as defined by the AGI, usually

has three to four basic mineral components:
PRODUCT
DESCRIPTION – 1.4.1 Quartz (SiO2 ±25-35%), appears as
irregular, watery-looking, or translucent
Granite grains.

1.0 GEOLOGICAL 1.4.2 Orthoclase Feldspar (KAlSi3O8

CLASSIFICATION ≈20-80%). In most, but not all, commercial,
geologic granites, the light-colored minerals,
1.1 The American Geological Institute white- to flesh-colored are orthoclase feldspar.
(AGI) defines granite as an intrusive igneous
rock (cooled slowly in the deep upper part of 1.4.3 Plagioclase Feldspar (NaAlSi3O8 to
the Earth’s crust) composed of 25% to 35% CaAl2Si3O8 ≈20-80%) features darker gray to
quartz and over 50% potassium- and sodium- bluish grains, with some grains exhibiting fine,
rich feldspars, with a common accessory grooved lines and/or an iridescent sheen.
mineral of less than 20%, usually muscovite Sometimes the mineral is a light, creamy color,
(clear mica), biotite (dark, iron-bearing mica), nearly indistinguishable from orthoclase,
or hornblende (amphibole). except for the occasional presence of the fine
lines.

1 The following terms are derivations of the word granolite. The use of these terms commercially is not
granite, which are now obsolete because their recommended.
definitions have become obscured and imprecise:
granide, granilite, granitelle, granitello, granitine, and

Page 5-8 • Granite  2016 Marble Institute of America

1.4.4 Dark accessory minerals (→20%) 1.6 Gneiss, a true metamorphic stone
biotite and hornblende are complex silicates that exhibits strong mineral segregation in the
with all the elements in quartz, orthoclase form of contorted bands indicating
feldspar, and plagioclase feldspar, plus iron and metamorphic origin, is universally included in
magnesium, which gives these minerals their the granite group by the stone industry.
dark color. Magnetite (Fe3O2) is often a trace Banded gneiss is a classical rock end member
mineral (±2-4%) in granite, and easily of the metamorphic process of high pressure,
recognized by its strongly magnetic property. time, temperature, and the presence of fluids
It, too, is black and opaque. Magnetite has a that begins with the sedimentary rock shale and
hardness rating of H=6, polishes well, has a proceeds through slate, to phyllite, then schist
metallic appearance, and is opaque (i.e., it does and finally, banded gneiss—from low to high
not transmit light even when very thin). levels of metamorphic rank.

1.4.5 All of these granitic minerals have a 2.0 COLOR AND VEINING
Mohs Scale2 hardness rating of H=7 or H=6
with the exception of biotite, which has a 2.1 The color of a granite is governed
variable hardness of 2.5 to 4.5, depending on largely by that of the feldspar, usually the most
the angle of the polished surface in relation to abundant mineral. However, it may be
the edges of the “books” of sheets that biotite modified to some extent by the quartz,
mica crystals exhibit. Thus, biotite does not hornblende, or mica, if considerable amounts
polish well and appears as small, rough spots on are present. Almost white, light gray, dark
a polished surface. This is not a flaw in either gray, green, pink, and red granites are
the stone or polishing, but simply the way common. Uniform color distribution is usually
biotite is—softer than all other minerals in a desirable feature. Lighter-colored granites
granite. Biotite hardness makes little difference are the average composition of continental
in most applications, as the overwhelmingly crust, while darker granites are more likely
dominant feldspar and quartz minerals are associated with or influenced by nearby oceanic
much harder. Biotite “plucks” slightly in composition stone.
polishing, but generally not when in use.
2.2 Dark, granular igneous rocks,
1.5 Granitization. Earth scientists came classified petrographically as anorthosite,
to realize that much granite is associated with basalt, diabase, diorite, and gabbro, are also
metamorphic stone of extremely high levels. used as dimension stone, and are classed
These are often massive, nonbanded commercially as “black granite.”
granites with no noticeable mineral
segregation into bands. Many examples come
from, but are not limited to, some Far Eastern
locations and Sri Lanka. These often have a
strong presence of red garnet3, a mineral
indicative of metamorphism. Geologic granite,
in terms of mineral content, can be formed by
granitization, a true metamorphic process
by which a solid rock is converted to granite by
entry and/or exit of material or change of
chemical components without going through a
liquid or molten state.

2See Appendix for information about the Mohs Scale of 3Garnet is most often noticeable when red, but also
mineral hardness. occurs in light green and light yellow.

 2016 Marble Institute of America Granite • Page 5-9

3.0 TEXTURE 7.0 PRODUCT SAMPLING

3.1 The term “texture,” as applied to 7.1 Granites are formed by nature; thus
granite, means size, degree of uniformity, and there are variations in the tonal qualities of the
arrangement of constituent minerals. stones. However, it is these natural differences
that make granites unique, valuable, and highly
3.2 The texture of granite is determined desirable. Because of these variations, selection
by the size and arrangement of mineral grains. of a granite should never be made on the basis
Uniform grain size usually is demanded in of one sample only. It is recommended that
commercial granites. Grain size varies greatly selection be based on viewing sufficient
in different types of granite. samples to show the complete range of colors
of the desired stone. MIA Members can
3.3 Uniform distribution of the minerals is provide these range samples.
as important as uniform grain size. Light and
dark minerals should be distributed evenly 8.0 PROPER USAGE TIPS
throughout the rock mass, for this gives
uniform color and texture. Many commercial 8.1 Recommendation for commercial
deposits display remarkable homogeneity; the floors:
rock may not vary in color or texture for many
feet, either vertically or horizontally. 8.1.1 Minimum ¾" thickness.

4.0 FINISHES 8.1.2 A honed finish.

4.1 Granite surfaces may be finished in a 8.1.3 A minimum hardness value of 25 as

number of ways. See the listing of typical measured by ASTM C241.
finishes on page 5-7 of this chapter.
8.2 Avoid the use of gypsum or molding
5.0 THICKNESS plaster setting spots for the installation of
stone.
5.1 Standard nominal thicknesses for
granite are generally 3/8", ¾", 1¼", 1½", 2", 9.0 VENEER CUTTING
3", 4", 6", and 8".
9.1 Quarry blocks are reduced to slabs by
6.0 SIZES a gang saw or wire saw. The gang saw consists
of a series of steel blades set parallel in a frame
6.1 Granite is a product of nature with that moves forward and backward. They are
hundreds of varieties available, each possessing fed a cutting abrasive in a stream of water.
unique characteristics. Little can be done to
alter the condition in which nature presents
these varieties to us. Therefore, size may TECHNICAL DATA –
become a limiting factor to consider in the
selection of a particular granite. Granite
6.2 A jointing scheme that permits the use 1.0 PROPERTIES OF GRANITE
of smaller sizes of granite will greatly facilitate DIMENSION STONE
selection and delivery. The MIA
Member/Supplier should assist in final 1.1 In centuries past, relatively little
approval. importance was attached to the ultimate
physical capabilities of most building materials.

Page 5-10 • Granite  2016 Marble Institute of America

Rule of thumb was a common structural design Property Range of Values
criterion. As a result, the widely used materials
Compressive Strength (C170)
of the day, for the most part natural rather than
lbs/in² .............................. 4,700-60,000
manmade materials, were seldom stressed to
Recommended (min): 19,000
their ultimate limits.
Flexural Strength (C880)
1.2 In present-day construction, this is far
lbs/in² ...................................700-5,500
from being true. Performance requirements
Recommended (min): 1,200
are daily becoming more demanding. In
striving for taller structures, greater spans,
Modulus of Elasticity (C1352)** (in millions)
firmer foundations, thinner walls and floors,
lbs/in²…………………………..2.0-10.0
stronger frames, and generally more efficient
buildings with more usable space, today’s
Density (C97), lb/ft3 .................. 150-200
Architects and Engineers must get the most out
Recommended (min): 160
of the materials with which they work.
Coefficient of Thermal Expansion,
1.3 Granite is a product of nature and not
in/in/ºF ........................4.7 x 10-6 average
always subject to the rules of consistent
behavior that may apply to manufactured
Modulus of Rupture (C99)
building materials.
lbs/in² ................................ 1,000-3,000
Recommended (min): 1,500
1.4 Physical property values of stone may,
however, be measured using the standard test
Absorption % (by weight) ........... 0.02-0.40
methods approved by the Dimension Stone
Recommended (max): 0.40
Committee C18 of ASTM International. The
MIA and Member companies are represented
Abrasion Resistance Ha ..................... 20-90
on the ASTM committee and are active in its
Recommended (min): 25
technical work of establishing proper test
methods and specifications consistent with the
latest technology. * Test methods described in current ASTM
standards.
1.5 Final design should always be based on
specific values for the stone variety ultimately ** Also known as Young’s Modulus.
to be installed. These values may be obtained
from the Stone Supplier. All materials are not 2.0 STRENGTH (ASTM C99,
suitable for all uses. In order to avoid mistaken C170, C880)
selections, tests for material values should be
made prior to final material selection. 2.1 Values for modulus of rupture,
compressive strength, and flexural strength are
1.6 Physical Properties of Granite ascertained by testing specimens of granite
(This historical data and information are under laboratory conditions until they fail.
provided only as a guideline. Recommended
minimums or maximums are established and The C170 procedure is used for determining
provided by ASTM International.)* the compressive strength of a granite
specimen. A cube or cylinder of 2" to 3" in all
dimensions is crushed under a hydraulic ram
and the compressive strength is calculated as
the total load divided by the area of the
specimen. Compressive strength of granite is

 2016 Marble Institute of America Granite • Page 5-11

seldom a factor in design, as the compressive 3.2 Underwriters’ fire-resistance ratings
strength is many times the anticipated evaluate whether or not a material will burn,
compressive stresses. This value is most often as well as how long it will keep surrounding
used for comparison of stone types or as a combustible materials from reaching
general strength benchmark for the material. temperatures that will cause them to ignite.
Methods of estimating fire-resistance periods
2.2 The C99 and C880 procedures are of masonry walls and partitions utilizing
both used for determining bending strength. component laminae are given in “Fire
The C99 procedure is much older, and the test Resistance Classifications of Building
protocol is seldom modified, so data obtained Construction,” BMS92, National Bureau of
from this test has some value for comparison to Standards.
historical data or between different stone
types. As a measure of resistance to bending 4.0 ABRASION RESISTANCE
loads, it is not considered to be a representative (ASTM C241)
modeling of panel behaviors in building
applications. The ratio of beam length to beam 4.1 Abrasion resistance is a property of
depth is very small, resulting in what is stone that should be tested per ASTM C241 to
referred to as “thick beam behavior.” The provide an indication of the stone’s wearing
results of this test are usually artificially high qualities when exposed to foot traffic.
due to the thick beam behavior and high shear
stresses in the loaded specimen 4.2 The hardness and uniform wearing
qualities of most granites make them extremely
2.3 The C880 procedure is much desirable and economically practical for floors
preferred when testing granite for resistance to and stairs. Varieties with an abrasive hardness
bending stresses. The procedure calls for a (Ha) of 25 or more, as measured by ASTM
span-to-depth ratio of 10:1, which eliminates C241 tests, are recommended for use as
the influence of thick beam behavior. flooring subject to normal foot traffic.
Furthermore, the test allows specimen
modification to allow the use of actual building
cladding thickness and actual finish, which 5.0 FACTORS AFFECTING
provides a better representation of the stone PROPERTIES
behavior in the cladding application. This
procedure also uses a four-point bending 5.1 The ultimate test of a building material
fixture, which provides a constant stress region is its ability to have and maintain the necessary
over approximately 50% of the specimen. This structural strength, as well as beauty of
provides a greater chance that the weakest appearance and low cost of maintenance, over
point of the specimen will fall within this the useful life of the structure. Experience has
region and produce more reliable data for proven that stone meets this test as few other
design use. building materials can. Studies have shown that
the durability of most stones is little affected by
3.0 FIRE RESISTANCE cycles of weather. This is because most have a
low rate of moisture absorption.
3.1 Stone is not combustible according to
underwriters’ ratings, and therefore is 6.0 SAFETY FACTORS
considered a fire-resistant material. Because of
its thermal conductivity, heat transfer is fairly 6.1 Good engineering practice requires
rapid. Most stone is not considered a highly that allowable design stress must provide a
rated thermal insulator. margin of safety in any structural element. As a
necessary precaution against such conditions as

Page 5-12 • Granite  2016 Marble Institute of America

wind, ice, snow, impact, temperature changes, Annotated Bibliography,” NBS Science Series
and imperfect workmanship, these allowable 67. The U.S. Army Corps of Engineers has also
stresses must be smaller than those that published TM 5-809-10, “Seismic Design for
produce failure. Buildings.”

6.2 Within the accepted limits of safe 8.0 EFFLORESCENCE AND

design practice, the closer the allowable load is STAINING
to the ultimate failure load in a structure, the
more efficient is the use of the material and the 8.1 Efflorescence is a salt deposit, usually
less the cost of the construction. white in color, which appears on exterior
surfaces of masonry walls. The efflorescence-
6.3 Contemporary building design does producing salts found in masonry are usually
not usually employ granite as part of the sulfates of sodium, potassium, magnesium,
structural frame, but rather as an independent calcium, and iron. Salts that are chlorides of
unit, a curtain wall, or veneer. Therefore, the sodium, calcium, and potassium will
primary concern in such cases is with wind or sometimes appear, but they are so highly
seismic loads. Safety factors of 3.0 for the soluble in water that they will be washed off by
granite and 4.0 for anchorage assemblies are rain.
recommended. Where the stone is to be
subjected to concentrated loading, such as stair 8.2 The water-soluble salts causing
treads or lintels supported only at the ends, a efflorescence come from other materials in the
factor of 4.0 or greater should be used. wall. The salts exist in small amounts and are
leached to the surface by water percolating
6.4 These safety factors may be adjusted through the wall. The most feasible means of
using sound engineering principles and prevention is to stop the entrance of large
judgment. amounts of water. Absorption from the face
will not cause efflorescence unless there are
6.5 As buildings become taller and open joints.
individual stone slab veneer becomes larger in
area, the lateral forces due to wind loads must 8.3 Some of the salt crystals may form in
be considered. Wind tunnel tests are often the stone’s pores near the surface. Crystal
used on major structures to determine wind growth (recrystallization) in the pores can
dynamics and force magnitude. cause stress on the walls of the pores and cause
the stone to flake off. If the conditions bringing
7.0 SEISMIC about this action persist, scaling may continue
CONSIDERATIONS and flake off, one layer after another. For this
to happen, large amounts of water must enter
7.1 Seismic considerations generally the wall and contain large amounts of salts.
require that low buildings be stiff, and that tall
buildings be relatively flexible. Design of 8.4 Research indicates that staining and
connections must account for seismically discoloration occurring on new buildings are
induced horizontal loading. Local building caused by the action of water percolating
codes vary and must always be checked to through concrete, from which soluble alkali
determine specific requirements for each area. salts are leached. The salts are then carried by
The National Bureau of Standards has published the water through the stone, where partially
two documents on the topic: “Earthquake oxidized organic matter is picked up. This is
Resistant Masonry Construction,” NBS Science then transported to the surface of the stone,
Series 106; and “Abnormal Loading on where it is deposited as a stain as the water
Buildings and Progressive Collapse: An evaporates.

 2016 Marble Institute of America Granite • Page 5-13

8.5 This staining phenomenon is similar to
efflorescence, except that it involves organic 9.2 Pitting does not make the granite less
material. It does not harm the stone, other than durable or of inferior quality. Pits exist in all
leaving an objectionable appearance during or granites and should be expected when dealing
soon after erection. However, if left alone, the with a natural, polished stone containing
stain is removed naturally by the action of the several types of minerals with different
elements, usually in the course of a few hardnesses.
months.
10.0 BACTERIA
8.6 Granite is one of the most durable of
all building materials because the quartz and 10.1 Bacteria requires several things in
feldspar in it are highly resistant to normal order to thrive and grow: oxygen, water,
weathering. Feldspars will, however, dis- sunlight, nutrients, and a substrate to form on.
integrate slowly if exposed to an acid-bearing The minerals in granite are toxic to bacteria. As
atmosphere, as in regions where hydro-carbons a result, there is no habitable environment for
are prevalent. All granites disintegrate very the bacteria to live and grow on a granite
slowly under repeated contraction and surface.
expansion due to diurnal and seasonal
temperature changes, but under ordinary
11.0 RADON AND GRANITE
atmospheric conditions, granite will endure for
years without significant change in color or
11.1 Radon is a naturally occurring gas
durability.
generated by the decay of trace amounts of
uranium found in the Earth’s crust. It is an
9.0 PITTING IN GRANITE unstable gas that quickly breaks down and
dissipates in the air.
9.1 Granites are made up of several
different minerals, each having a different 11.2 Radon is measured in units called
hardness. They can contain feldspars, biotites, picocuries per liter (pCi/l). A picocurie is one
amphiboles, ferrous titanium oxides, and other trillionth (10-12) of a curie, which is the amount
mineral combinations. For comparison, on the of radioactivity emitted by a gram of radium.
Mohs Scale, diamonds are the hardest The U.S. Environmental Protection Agency
substance, with a hardness of 10. By has established 4 pCi/l as the standard for
comparison, feldspars have a hardness of 6.5 to indoor air; 20 pCi/l represents the maximum
7, which is still quite hard and durable. amount of exposure to radium that is now
Biotites, the black minerals throughout the allowed by U.S. regulations.
slab, are by contrast very soft (2.5 to 4.5) and
flake easily. All true granites have biotite in 11.3 Measurements of Radon from
their composition. Because biotites are soft and Granite Countertops. “Over 500
flaky, the first few layers are removed during measurements of radon emissions from granite
the polishing process, causing pits. Some have been published in the peer reviewed
granites have more biotites throughout their scientific literature.4” This study and other
composition than others. The higher the biotite radon and radiation information and test results
content of the stone, the more pits it will have. may be found at http://www.marble-
All polished igneous/metamorphic rock will institute.com/radon/. None of the research
have varying degrees of pits, depending on the found a single stone that would be a health risk
amount of biotites, muscovite, and phlogopite. to homeowners.

4Natural Stone Countertops and Radon, 2008.

Environmental Health & Engineering, publisher.

Page 5-14 • Granite  2016 Marble Institute of America

12.0 CAUTION ABOUT
ENHANCED GRANITE

12.1 Several methodologies are being used

to enhance varieties of granite. Caution, in
some cases avoidance, should be exercised for
the following methodologies:

12.1.1 Tinting. The adding of color dyes in

sealer-type products to make the color of the
stone conform to a more pleasing one. This is
a short term “fix,” as the color will bleed out
from the stone when it is exposed to the sun,
or is otherwise used.

12.1.2 Epoxy (polyester) Filling. Several

varieties of over-burdened stones that do not
meet the ASTM criteria for Granite Dimension
Stone are being filled with epoxy or polyester
resins (similar to the typical filling techniques
employed in travertine) and marketed for a
variety of uses. This type of stone is generally
not suitable for wet or exterior applications.

12.1.3 Resin filling. This process is being

performed to reduce the effects of “pits” in
granite. Once treated, these stones are
required to be marketed as “filled.” Verify with
the Producer and the End User that the type of
fill being used is both safe and acceptable for
the application intended.

 2016 Marble Institute of America Granite • Page 5-15

NOTES:

Page 5-16 • Granite  2016 Marble Institute of America

LIMESTONE 1.2.3.3 Additional publications may be
available from the MIA Bookstore. Go online
at www.marble-institute.com.
1.0 GENERAL
1.2.4 Indiana Limestone Institute of
1.1 Related Documents America (ILI)
1.1.1 Drawings and general provisions, 1.2.4.1 Indiana Limestone Handbook
including General and Supplementary
Conditions of the Contract and Division I 1.3 Scope of Included Work
Specification sections, apply to this section.
1.3.1 The work to be completed under this
1.2 Applicable Publications contract includes all labor and materials
required for the furnishing and installation of
1.2.1 The following publications listed here all limestone work shown or called for on the
and referred to thereafter by alphanumeric contract drawings, specifications, and
code designation only, form a part of this addenda.
specification to the extent indicated by the
references thereto: 1.4 Definition of Terms
1.2.2 ASTM International (ASTM): 1.4.1 The definitions of trade terms used in
this specification shall be those published by the
1.2.2.1 C568, Standard Specification for MIA, ILI, or ASTM International.
Limestone Dimension Stone

1.2.2.2 C97, Standard Test Methods for

1.5 Source of Supply
Absorption and Bulk Specific Gravity of
Dimension Stone 1.5.1 All limestone shall be obtained from
quarries having adequate capacity and facilities
1.2.2.3 C99, Standard Test Method for to meet the specified requirements, and from a
Modulus of Rupture of Dimension Stone firm equipped to process the material promptly
on order and in strict accord with
1.2.2.4 C170, Standard Test Method for specifications. The Specifying Authority
Compressive Strength of Dimension Stone (architect, designer, engineer, contracting
officer, end user etc.) reserves the right to
1.2.2.5 C241, Standard Test Method for approve the Material Supplier prior to the
Abrasion Resistance of Stone Subjected to award of this contract. Stone and workmanship
Foot Traffic quality shall be in accordance with Industry
Standards and Practices as set forth by the MIA.
1.2.2.6 C880, Standard Test Method for
Flexural Strength of Dimension Stone 1.6 Samples

1.2.3 Marble Institute of America 1.6.1 The Limestone Contractor shall submit
(MIA): through the General Contractor, for approval
by the Specifying Authority, at least two sets of
1.2.3.1 Membership, Products, and Services samples of the various kinds of limestone
Directory specified. The sample size shall be 1'-0" x 1'-0"
and shall represent approximately the finish,
1.2.3.2 Dimension Stone Design Manual texture, and anticipated range of color to be
supplied. One set of approved samples shall be

 2016 Marble Institute of America Limestone • Page 6-1

retained by the Specifying Authority, and one changes be made. Each stone indicated on the
set shall be returned to the Limestone Supplier setting drawings shall bear the corresponding
for his/her record and guidance. It is noted number marked on an unexposed surface.
herein that limestone is a natural material and Provision for the anchoring, doweling, and
will have intrinsic variations in color, cramping of work, in keeping with standard
markings, and other characteristics. practices, and for the support of stone by shelf
Depending on limestone selected and quantity angles and loose steel, etc., when required,
required, a range mockup may be used to shall be clearly indicated on the shop drawings.
further define the characteristics of the NO FABRICATION OF LIMESTONE SHALL
material. Cost of mockup, if required, shall not BE STARTED UNTIL SUCH DRAWINGS
be included in this section. HAVE BEEN FULLY APPROVED AND
MARKED AS SUCH. The Limestone
1.6.2 Prior to fabrication, an inspection and Contractor shall not be responsible for
approval by the Specifying Authority (and/or determining, making, or verifying (1) design,
General Contractor and/or End User) of a structural, wind, seismic, or other design
representative number of the finished slabs loads; (2) engineering estimates; (3) plans or
may be desirable to understand the finish and specifications; or (4) the types, sizes, or
full range of the material. locations of anchors, unless specifically added
to the scope of work.
1.7 Shop Drawings
1.8 Defective Work
1.7.1 The Limestone Contractor shall submit
through the General Contractor, for approval 1.8.1 Any piece of limestone showing flaws or
by the Specifying Authority, sufficient sets of imperfections upon receipt at the storage yard
shop drawings, showing general layout, or building site shall be referred to the
jointing, anchoring, stone thickness, and other Specifying Authority for determination as to
pertinent information. These drawings shall responsibility and decision as to whether it shall
show all bedding, bonding, jointing, and be rejected, patched, or redressed for use.
anchoring details along with the net piece
dimensions of each limestone unit. One copy 1.9 Repairing Damaged Stone
of the approved shop drawings shall be retained
by the Specifying Authority, one copy shall be 1.9.1 Repair of stone is an accepted practice
retained by the General Contractor, and one and will be permitted. Some chipping is
copy returned to the Limestone Contractor for expected; repair of small chips is not required
fabrication. All jointing as shown by the if it does not detract from the overall
Specifying Authority on the contract drawings appearance of the work, or impair the
shall be followed, unless modifications are effectiveness of the mortar or sealant. The
agreed upon in writing, or indicated upon the criteria for acceptance of chips and repairs will
approved shop drawings. If the contract be per standards and practices of the industry
drawings do not show the intent of the jointing, unless other criteria are mutually agreed upon
it will be the fabricator's responsibility to in writing by the Limestone Contractor and the
establish the jointing in accordance with Specifying Authority.
industry standards and practices.

1.7.2 The cutting and setting drawings shall be

based upon and follow the drawings and full
size details prepared by the Specifying
Authority except where it is agreed in writing
or shown on the approved shop drawings that
Page 6-2 • Limestone  2016 Marble Institute of America
2.0 MATERIALS underlayment, the use of nonstaining cement
may not prevent all discoloration.
2.1 Limestone Discoloration will disappear as the stone dries.

2.1.1 General: All limestone shall be of 2.2.2 The addition of hydrated lime or like
standard architectural grade, free of cracks, amounts of ground limestone may increase
seams, or other traits which may impair its initial shrinkage, but the improved working
structural integrity or function. Inherent color qualities and the water retention will enable
variations characteristic of the quarry from the mixture to adjust to the initial shrinkage
which it is obtained will be acceptable. Texture and will give good bonding strength in both
and finish shall be approved by the Specifying horizontal and vertical joints. Hydrated lime
Authority as shown in the samples. should conform to ASTM C207 Type S.

2.1.2 ASTM C568 [C97] [C99] [C170] 2.2.3 Sand should comply with ASTM C144.
[C241] [C880] See the chart of applicable
ASTM standards and tests in the Appendix. 2.2.4 Mixing water must be potable quality.

2.1.3 Schedule: Limestone shall be 2.2.5 Mortar mixes vary in proportions from
provided as follows: a hard mixture (1:1:4) to a flexible mixture
(1:1:9). Hard mixes can be expected to set up
stress conditions between the stone and mortar
2.1.3.1 For (state location on building) (state
in joints since the thermal coefficient of mortar
name, grade (if applicable), and (color)
expansion is greater than that of stone. In
limestone with a (type) finish, supplied by (name
paving installations, stress is often sufficient to
company or list several approved suppliers).
break the bond between the stone and the
substrate. Flexible mortars are not suitable for
2.1.3.2 Provide information as in (1) for
exterior work.
each different limestone/finish combination in
the project.
2.2.6 The Indiana Limestone Institute
recommends a 1:1:6 or Type N mortar be used
2.1.4 Finishes: Finishes listed in the with Indiana limestone.
schedule shall conform with definitions by the
MIA, ILI, or ASTM International.
2.3 Pointing Mortar
2.2 Setting Mortar 2.3.1 Pointing mortar shall be composed of
one part (white or other) portland cement, one
2.2.1 Cement used with limestone shall be part hydrated lime, and six parts white sand
white portland cement, ASTM C150, or white passing a #16 sieve.
masonry cement, ASTM C91. Non-staining
cement (at the present time there are few
masonry cement mortars produced labeled
2.4 Sealants and Backup
nonstaining) shall contain not more than Material (If Applicable)
0.03% of water-soluble alkali when
determined in accordance with procedure 2.4.1 Where specified, (state type or name of
#15, calculation #16 of ASTM C91 or Federal sealant) shall be used for the pointing of joints.
Specification SS-C181C. However, if a large The backup material used with the sealant shall
amount of normal cement has been used in the be (identify material).
backup (underlayment) material, and if an
effective water barrier has not been provided
between the stone and the backup or

 2016 Marble Institute of America Limestone • Page 6-3

2.5 Anchors, Cramps, and joints shall have a uniform thickness of 3/8"
Dowels unless otherwise shown or noted on drawings.

2.5.1 The Limestone Contractor shall furnish 3.1.2 Reglets for flashing, etc., shall be cut in
and set all anchors shown on approved shop the stone where so indicated on the drawings.
drawings unless otherwise specified. All All flashing, whether installed by the Stone
anchors shall be fabricated from Type 304 or Contractor or others, must be installed with
316 stainless steel or other suitable nonferrous nonstaining, oil-free caulk.
metal. Multipart anchors may contain metal
other than stainless steel provided such metal is 3.2 Backs of Pieces
not embedded in sinkages in the limestone.
3.2.1 Backs of pieces shall be sawn or roughly
2.6 Stain Prevention dressed to approximately true planes. Back
surfaces shall be free of any matter that may
2.6.1 Where necessary, such as when create staining.
limestone is used at/below grade or at
horizontal water stops, specify one or both of 3.3 Moldings, Washes, and Drips
the following systems:
3.3.1 Moldings, washes, and drips shall be
2.6.1.1 Dampproof unexposed stone constant in profile throughout their entire
surfaces. Joint surfaces should be dampproofed length, in strict conformity with details shown
only to within 1" of finished surface when using on approved shop drawings. The finish quality
bituminous solutions. on these surfaces shall match the finish quality
of the flat surfaces on the building.
2.6.1.2 Dampproof all concrete surfaces on
which limestone will rest. Dampproof adjacent 3.4 Back-checking and Fitting to
concrete structure, haunches, etc. Structure or Frame
2.7 Adjacent To Water 3.4.1 Stone coming in contact with structural
work shall be back-checked as indicated on the
2.7.1 Limestone used in areas adjacent to approved shop drawings. Stones resting on
water that is chemically purified should be structural work shall have beds shaped to fit the
tested to ensure that there is no reaction supports as required.
between the stone and the purification
chemicals. 3.4.2 Maintain a minimum of 1" between
stone backs and adjacent structure. (Note:
(See Horizontal Surfaces chapter for more many bolted connections will require more
information.) space than this; 2" space may be more
desirable. Large-scale details should illustrate
3.0 FABRICATION and control these conditions.)

3.1 Beds and Joints 3.5 Cutting for Anchoring,

Supporting, and Lifting Devices
3.1.1 All stone shall be cut accurately to shape
and dimensions and full to the square, with 3.5.1 Holes and sinkages shall be cut in stones
jointing as shown on approved drawings. All for all anchors, cramps, dowels, and other
exposed faces shall be dressed true. Beds and tieback and support devices per industry
joints shall be at right angles to the face, and standard practice or approved shop drawings.
However, additional anchor holes may be
Page 6-4 • Limestone  2016 Marble Institute of America
drilled at job site by Limestone Contractor to contract shall be loaded and shipped in the
facilitate alignment. sequence and quantities mutually agreed upon
by the General Contractor, Limestone
3.5.2 No holes or sinkages will be provided Contractor, and the Limestone Fabricator.
for Limestone Contractor’s handling devices
unless arrangement for this service is made by 4.2 Unloading and Storage at Job
the Limestone Contractor with the Limestone Site
Fabricator.
4.2.1 Receipt, storage, and protection of
(NOTE: It is not recommended that lewis pins limestone work prior to and during installation
be used for stones less than 3½" thick.) shall be the responsibility of the Limestone
Contractor.
3.6 Cutting and Drilling for
Other Trades 4.2.2 All limestone shall be received and
unloaded at the site with necessary care in
3.6.1 Any miscellaneous cutting and drilling handling to avoid damaging or soiling.
of stone necessary to accommodate other
trades will be done by the Limestone 4.2.3 Stones shall be stored above the ground
Fabricator only when necessary information is on nonstaining skids (cypress, white pine,
furnished in time to be shown on the shop poplar, or yellow pine without an excessive
drawings and details, and when work can be amount of resin). Chemically treated wood
executed before fabrication. Cutting and should not be used. DO NOT USE
fitting, due to job site conditions, will be the CHESTNUT, WALNUT, OAK, FIR, AND
responsibility of the Limestone Contractor. OTHER WOODS CONTAINING TANNIN.
Completely dry limestone shall be covered
3.6.2 Incidental cutting such as for window with nonstaining waterproof paper, clean
frame clips, etc., which is normally not canvas, or polyethylene.
considered to be the responsibility of the Stone
Supplier, will be provided only by arrangement 5.0 INSTALLATION
by the General Contractor and Limestone
Contractor with the Limestone Fabricator. 5.1 General Installation
3.7 Carving and Models 5.1.1 Installation shall be accomplished with
competent, experienced Stone Setters, in
3.7.1 All carving shall be done by skilled Stone accordance with the approved shop drawings.
Carvers in a correct and artistic manner, in
strict accordance with the spirit and intent of 5.1.2 All limestone pieces shall be identified
the approved shop drawing, or from models with a unique piece number corresponding
furnished or approved by the Specifying with the number on the shop drawings.
Authority. Interchanging of numbered pieces is not
permitted.
4.0 SHIPPING AND HANDLING
5.1.3 Limestone shall be free of any ice or
4.1 Packing and Loading frost at time of installation. Salt shall not be
used for the purpose of melting ice, frost, or
4.1.1 The cut limestone shall be carefully snow on the limestone pieces.
packed for transportation with exercise of all
customary and reasonable precautions against
damage in transit. All limestone under this

 2016 Marble Institute of America Limestone • Page 6-5

5.1.4 Adequate protection measures shall be 5.2.6 While joints can be tooled when initial
taken to ensure that exposed surfaces of the set has occurred, pointing cut stone after
stone shall be kept free of mortar at all times. setting, rather than full bed setting and
finishing in one operation reduces a condition
5.2 Mortar Setting which tends to produce spalling and leakage. It
is generally best to set the stone and rake out
5.2.1 All limestone shall be set accurately in the mortar to a depth of ½" to 1½" for
strict accordance with the contract, approved pointing with mortar or sealant at a later date.
shop drawings, and specifications. White If pointed with sealant, the raked depth and
portland cement with a low-alkali content is sealant applications shall conform to
recommended. manufacturer’s instructions.

5.2.2 Cut limestone is customarily shipped as 5.2.7 Projecting stones shall be securely
it comes from its final operation in the propped or anchored until the wall above is set.
supplier’s plant. Its surfaces and joints may be
covered with dust or saw slush, especially those 5.2.8 Only the ends of lugged sills and steps
pieces which have not been exposed to rain in shall be embedded in mortar. Balance of joint
stacking areas. Cleaning prior to installation or shall be left open until finally pointed.
erection of cut limestone is typically not
required where the existence of dust or saw 5.2.9 All cornice, copings, projecting belt
slush does not impede the erection process or courses, other projecting courses, steps, and
the application of joint sealants or pointing. platforms (in general, all stone areas either
The exception to this rule is interior partially or totally horizontal) should be set
stonework. Thoroughly clean interior stones with unfilled vertical joints. After setting,
prior to installation and protect the work once insert properly sized backup material or backer
in place from construction traffic. Among the rod to proper depth, and gun in sealant.
methods used is washing with a fiber brush and
soap powder, followed by a thorough rinsing In cold weather, the International Masonry
with clear water. Further information on Industry All Weather Council re-
cleaning can be found in section 6.1 of this commendations for setting from 40ºF to 20ºF
document. (4ºC to -6ºC) shall be followed, except that no
additives shall be used in the setting mortar,
5.2.3 All stone joint surfaces not thoroughly and below 20ºF (-6ºC), all work shall be done
wet shall be drenched with clear water just in heated enclosures.
prior to setting.
5.2.10 Individually set thin tile (nominal
5.2.4 Except as otherwise specially noted, 3/8" thick) on vertical surfaces exceeding 8' is
every stone shall be set in full beds of mortar not recommended.
with all vertical joints slushed full. Completely
fill all anchor, dowel, and similar holes. All bed 5.3 Anchorage
and vertical joints shall be 3/8" unless
otherwise noted. 5.3.1 All limestone shall be anchored in
accordance with the approved shop drawings.
5.2.5 Plastic setting pads shall be placed under
heavy stones, column drums, etc., in the same 5.3.2 To the furthest extent possible, all
thickness as the joint, and in sufficient quantity anchor preparations in limestone units shall be
to avoid squeezing mortar out. Heavy stones or shop-applied.
projecting courses shall not be set until mortar
in courses below has hardened sufficiently to 5.3.3 All anchorage devices and anchor
avoid squeezing. hole/slot fillers shall be in accordance with
Page 6-6 • Limestone  2016 Marble Institute of America
ASTM C1242. Care must be taken to ensure in strict accordance with the printed
that any holes capable of retaining water are instructions of the Sealant Manufacturer.
filled after use to prevent water collection and
freezing. 5.6.2 All sealants shall be tooled to ensure
maximum adhesion to the contact surfaces.
5.4 Sealant Joints
5.7 Weep Tubes
5.4.1 Where so specified, joints requiring
sealant shall be first filled with a closed-cell 5.7.1 Plastic or other weep tubes shall be
ethafoam rope backer rod. The backer rod placed in joints where moisture may
shall be installed to a depth that provides accumulate within the wall, such as at base of
optimum sealant profile after tooling. cavity, continuous angles, flashing, etc., or as
shown on architectural drawings.
5.4.2 If recommended by the Sealant
Manufacturer, primers shall be applied to the 6.0 CLEANING AND
substrate surfaces according to the
PROTECTION
manufacturer’s directions prior to application
of the joint sealant.
6.1 Cleaning
5.5 Expansion Joints
6.1.1 Among the methods most frequently
used to clean cut limestone are washing with a
5.5.1 Joints shall be adequate to allow for
fiber brush and soap powder, followed by a
thermal and structural differential movement.
thorough rinsing with clear water. Pressure
washing is another option, and often the
5.5.2 Filler material for these joints shall be
required pressure can be delivered from
nonstaining.
ordinary hose taps. Greater water pressure can
be used in some situations if delivered by a
5.5.3 It is not the intent of this specification to
wide-angle nozzle from a distance no closer
make control or expansion-joint
than one foot to the stone surfaces. Most often
recommendations for a specific project. The
a lower pressure and greater distance will be
Specifying Authority must specify expansion
equally effective. Suppliers or trade
and control joints and show location and details
associations representing the specified
on the drawings.
limestone should be contacted for pressure
recommendations for their particular product.
5.5.4 MIA recommends a maximum area of
400 square feet between expansion/control
6.1.2 Special consideration and protection
joints for horizontal surfaces. In areas where
shall be provided when brickwork is cleaned
there are large sections of natural light, this
above the limestone. Strong acid compounds
area should be reduced dependent on the
used for cleaning brick will burn and discolor
quantity of natural light entering the area. In
the limestone.
glass ceiling atriums, it has been shown that
120 square feet is the maximum area that an
6.1.3 In general, sand-blasting, wire brushes
expansion/control joint should encamp.
or acids should never be used on limestone.
When circumstances arise that cause one or
5.6 Caulking more of these methods to be considered,
suppliers or trade associations representing the
5.6.1 Where so specified, joints shall be specified limestone should be contacted for
pointed with the sealant(s) specified in Section recommendations.
2.4, after first installing the specified backup
material and applying a primer if required, all
 2016 Marble Institute of America Limestone • Page 6-7
6.2 Protection of Finished Work an extremely rare example). Most limestone
is marine in origin, composed of micro-sized
6.2.1 During construction, tops of walls shall fossils of marine invertebrate organisms rather
be carefully covered at night and especially like the shells found on most beaches.
during any precipitation or other inclement Limestone composed of inorganic, precipitated
weather. calcium carbonate is rare, and even more rare
is limestone of igneous origin called
6.2.2 At all times, walls shall be adequately carbonatites,2 found in diamond-bearing rock. In
protected from droppings. former times it was thought that pure, fine-
grained limestone was a precipitate from
6.2.3 Whenever necessary, substantial marine waters superenriched with calcium
wooden covering shall be placed to protect the carbonate, but that is not the case; almost all
stonework. Nonstaining building paper or fine-grained limestone is of biological origin.
membrane shall be used under the wood.
Maintain all covering until removed to permit 1.2 Limestone is a carbonate stone, that is,
the final cleaning of the stonework. it has the -CO3 radical combined with the
calcium atom. Other carbonate minerals seen
6.2.4 The Limestone Contractor will outline in dimension stone are the carbonates siderite
the needs for protection in writing to the (FeCO3), magnesite (MgCO3), and dolomite
General Contractor. The General Contractor Ca,Mg(CO3) 2. Dolomite is both a mineral and
shall be responsible for protection of the a stone, and is used extensively as a commercial
finished work until all trades are finished. This limestone. The origin of dolomite is
responsibility includes the stone cleaning costs postdepositional; it is chemically transformed
prior to the final inspection. from a pure calcium limestone after deposition
and burial, and sometimes, after total
cementation. Thus the dolomitization process
of a limestone is termed a “diagenetic” chemical
PRODUCT process in which magnesium ions are inserted
DESCRIPTION – into the calcium carbonate molecules to make
Limestone dolomite, both the mineral and rock.

1.3 All the carbonate minerals mentioned

1.0 GEOLOGICAL share certain chemical and physical properties:
CLASSIFICATION they are all approximately the same hardness
(H=3) on the Mohs Scale3; all have three good
1.1 Limestone is a sedimentary stone with cleavages (i.e., they easily break into
at least 50% by weight calcite or calcium parallelograms, indicating they have the same
carbonate (CaCO3) content1. However, atomic geometry); and they all react in some
commercial limestone usually has a much manner to cold, dilute hydrochloric acid and
higher percentage of calcium carbonate than other dilute acids.
50%. Limestone is a “clastic” sedimentary
stone. Almost all limestone is composed of 1.4 Since limestone by definition must be at
grains or fragments of biologic origin, ranging least 50% calcium carbonate, the other 50%
from fossils or organically derived grains that can be one of various clasts or minerals of other
weigh a mere fraction of an ounce, to dinosaur kinds of stone. These include clay, silt, quartz
bones that may weigh tons (though the latter is or other sands, pebbles, and especially fossils–

1 The Glossary of Geology, 2nd ed., 1980, Bates and 2 Carbonatites often occur in kimberlite pipes, a rare and
Jackson eds., Amer. Geol. Inst. special kind of geologic formation in which diamonds
are found.
3 See Appendix for the Mohs Scale of mineral hardness.

Page 6-8 • Limestone  2016 Marble Institute of America

usually calcite or aragonite (a mineral with the 1.8 Clay is the source of coloring in many
same chemistry as calcite (CaCO3), but with an limestones, because it contains the iron oxides
unstable atomic geometry unlike calcite, which that yield yellow through red stain; thus, a very
has a stable atomic geometry. small component of clay may be acceptable in
commercial limestone. A simple chemical
1.5 It is proper to add a descriptive prefix in analysis of a limestone will indicate precisely
identifying types of stone; for example, muddy the percent of calcite composition, while a
or shaly limestone, or silty, sandy, or pebbly petrographic examination would establish the
conglomeratic limestone. characteristics of the calcite/clay mixture.
Large inclusions or bands of clay seriously
1.6 Dolomite, the stone, is a calcium- weaken the stone.
magnesium carbonate classed in the dimension
stone industry as “limestone,” and is important 1.9 Recrystallization of any limestone is
commercially not only due to the large amount usually initiated with burial, and the deeper the
quarried and sold, but because of two special burial, the more pervasive is the
physical properties of dolomite: recrystallization. Grain size has much to do
with the process of recrystallization in some
1.6.1 Dolomite is somewhat less soluble than types of limestone; it appears to proceed
calcite, enough so that dolomite generally rapidly in some very fine-grained limestones,
exhibits somewhat greater weathering perhaps accelerated by trace amounts of
resistance in exterior applications. The biological material and the larger amount of
standard procedure to test for calcite is to put surface area of multiple small grains. Marbles
a drop of dilute hydrochloric acid (HCl), ≈10% by geological definition are metamorphic
or less, on the mineral. A vigorous “fizzing” limestones. It is often nearly impossible to
reaction occurs immediately, a positive differentiate a strongly recrystallized limestone
indication of calcite. By contrast, a drop of from a marble because the two behave exactly
dilute HCl on dolomite mineral or stone the same; thus in commercial practice, the
produces no reaction unless the dolomite is differentiation is often incorrectly stated, but
pulverized first; then a fizzing reaction is the error may be of little or no importance. If
observed, but it will be less vigorous than with the exact name and origin is needed, a
calcite. metamorphic marble can be identified by
indications of strain in calcite crystals observed
1.6.2 Dolomite hardness H=3.5 is slightly in a petrographic thin-section.
harder than calcite. Calcite hardness is H=3 by
comparison, a human fingernail is H=2.5, and 1.10 Many fossiliferous limestones are of
the mineral fluorite (CaF2) is H=4. Thus exceptional biological interest as they form in a
dolomite hardness at 3.5 will scratch the softer variety of mostly marine environments much
calcite. Although this doesn’t seem like much studied for baseline standards against which
of a difference, it is enough of an increase to modern environments are compared. These
provide longer service life in high abrasion would include constructional biological reefs,
applications, for instance, for entrance steps. barrier reefs like Australia’s Great Barrier
Reef, lagoons and carbonate tidal flats similar
1.7 In general, limestone diluted with too to the back side of Andros Island in the
much clay, sand, or other noncarbonate grains Bahamas, or Florida Bay. Fossiliferous
is not acceptable as dimension stone—it may limestone has fascinated mankind since ancient
not be well enough cemented to hold together, times, and continues to be a stone in high
the clays may wash out, or if sandy, the sands demand. Fossils over three billion years old are
may wash or weather out too easily, or the studied from carbonate rocks. Fossiliferous
stone will not take an acceptable finish. limestone preserves the only record of life
available for the period of Earth history prior

 2016 Marble Institute of America Limestone • Page 6-9

to the advent of mankind, and retains the 4.1.4 Abrasive: A flat, nonreflective surface.
charisma associated with unknown creatures
from times long past. 4.1.5 Sawn: A comparatively rough surface;
can be chat, shot, sand, or diamond sawn.
2.0 COLOR AND VEINING
4.1.6 Polished: Mirror gloss, with sharp
2.1 The color, veinings, clouds, mottlings, reflections.
and shadings in limestone are caused by
substances included in minor amounts during 4.1.7 Bush-hammered: Textured surface
formation. These include iron-bearing that varies from subtle to rough.
minerals, clay, and organic material thought to
be residual from the soft parts of tiny marine 4.1.8 Thermal (Flamed): Finish produced
animals. Most of these dark materials are found by application of high-temperature flame to the
between calcite crystals or the shell materials, surface. Large surfaces may have shadow lines
and some shells and calcite crystals are darker caused by overlapping of the torch. This finish
than others. Colors of biologic inclusions are will vary in texture and depth between
strongly affected by the environment of different types of limestone, as the finish is
deposition, e.g., whether bottom conditions largely dependent upon the limestone
are aerobic or anaerobic. Iron oxides make the structure of the stone. The thermal method is
pinks, yellows, browns, and reds. Most grays, not commonly used on limestone.
blue-grays, and blacks are of bituminous
origin. 4.1.9 Antiqued: A finish that replicates
rusticated or distressed textures.
3.0 TEXTURE
4.1.10 Tumbled: A weathered, aging
3.1 The term “texture,” as applied to finish created when the stone is tumbled with
limestone, means size, degree of uniformity, sand, pebbles, or steel bearings.
and arrangement of constituent minerals.
4.1.10.1 Other finishes such as machine
3.2 Limestone contains a number of tooled are available and it should be noted that
distinguishable natural characteristics, not all finishes may be applicable to all
including calcite streaks or spots, fossils or shell limestones.
formations, pit holes, reedy formations, open
texture streaks, honeycomb formations, iron 4.1.11 Some stone finishes can affect
spots, travertine-like formations, and grain- strength and durability. Examples are bush-
formation changes. One or a combination of hammered and thermal finishes, which reduce
these characteristics will affect the texture. a stone’s thickness, making it more vulnerable
to weakening from exposure to freeze and
thaw cycles.
4.0 FINISHES
4.1.12 The type of finish desired may affect
4.1 Limestone surfaces may be finished in a
the final cost. For further information on cost
number of ways. Typical finishes are:
differences between various finishes contact
MIA member companies.
4.1.1 Honed: A satin smooth surface with
little or no gloss.
5.0 THICKNESS
4.1.2 Smooth: Smooth finish, with minimum
of surface interruption. 5.1 Standard nominal thicknesses for
limestone are generally 3/8", ¾", 1¼", 1½",
4.1.3 Plucked: A rough texture. 2", 2¼", 2½", 3", 3½", and 4". The
Page 6-10 • Limestone  2016 Marble Institute of America
recommended thicknesses vary depending on 8.1.1 Minimum ¾" thickness.
the type of limestone used.
8.1.2 A honed finish.
5.2 Cutting can be made to exact metric
measurements through conversion of U.S. 8.1.3 A minimum hardness value of 10 as
Conventional System values to SI International measured by ASTM C241.
System units. See conversion table in the
Appendix. 8.2 Avoid the use of gypsum or molding
plaster setting spots for the installation of
Note that as limestone is cut thinner, its tensile limestone.
strength is diminished.
9.0 VENEER CUTTING
6.0 SIZES
9.1 Quarry blocks are reduced to slabs by a
6.1 Limestone is a product of nature with gang saw, belt saw, or wire saw. The gang saw
many varieties available, each possessing consists of a series of steel blades set parallel in
unique characteristics. Little can be done to a frame that moves forward and backward.
alter the condition in which nature presents They are fed a cutting abrasive in a stream of
these varieties to us. Therefore, size may water. See illustration at end of chapter 7.
become a limiting factor to consider in the
selection of a particular limestone. 10.0 DAMPPROOFING
6.2 MIA Members should be consulted for 10.1 Some limestones have moisture
specific size information for a particular stone absorption rates which will cause bleeding of
and its desired use. A jointing scheme which setting or joint materials. If unsure, test the
permits the use of smaller sizes of limestone limestone for tolerance of the setting material.
may greatly facilitate selection and delivery. Wetting the joint surfaces prior to applying the
The MIA Member/Supplier should assist in the mortar and avoiding the use of too much water
final scheme approval. in the mix may reduce the probability of such
bleeding If necessary, edges and back faces
7.0 PRODUCT SAMPLING must be dampproofed with materials that will
bond with the setting/jointing material, but
7.1 Limestone is formed by nature; thus not cause bleeding.
there are variations in the tonal qualities of the
stones. However, it is these natural variations
that make limestone unique, valuable, and TECHNICAL DATA –
highly desirable. Because of these variations,
selection of a limestone should never be made Limestone
on the basis of one sample only. It is
recommended that selection be based on 1.0 PROPERTIES OF
viewing sufficient samples to show the general LIMESTONE DIMENSION STONE
range of colors of the desired stone. MIA
Members can provide these range samples. 1.1 In centuries past, relatively little
importance was attached to the ultimate
8.0 PROPER USAGE TIPS physical capabilities of most building materials.
Rule of thumb was a common structural design
8.1 Recommendation for commercial criterion. As a result, the widely used materials
floors: of the day, for the most part natural rather than
manmade materials, were seldom stressed to
their ultimate limits.
 2016 Marble Institute of America Limestone • Page 6-11
1.2 In present-day construction, this is far Property Range of Values
from being true. Performance requirements
Flexural Strength (C880)
are daily become more demanding. In striving
lbs/in² ................................. 400-2,700
for taller structures, greater spans, firmer
foundations, thinner walls and floors, stronger Modulus of Elasticity5 (in millions)
frames, and generally more efficient buildings lbs/in² ..................................... 0.6-1.4
with more usable space, today’s Architects and
Engineers must get the most out of the Density, lb/ft3 (C97) ................. 110-185
materials with which they work. Recommended (min):
110 (low density),
1.3 Limestone is a product of nature and not 135 (medium density),
always subject to the rules of consistent 160 (high density)
behavior that may apply to manufactured
building materials. Coefficient of Thermal Expansion,
in/in/ºF ......................... 4.4 x 10-6 average
1.4. Physical property values of limestone
may, however, be measured using the standard Modulus of Rupture (C99) lbs/in²...400-1000
test methods approved by the Dimension Stone Recommended (min):
Committee C18 of ASTM International. The 400 (low density),
MIA and Member companies are represented 500 (medium density),
on the ASTM committee and are active in its 1,000 (high density)
technical work of establishing proper test
methods and specifications consistent with the Absorption % (by weight) (C97) ... 0.6-29.0
latest technology. Recommended (max):
12.0 (low density),
1.5 Final design should always be based on 7.5 (medium density),
specific values for the stone variety ultimately 3.0 (high density)
to be installed. These values may be obtained
from the Stone Supplier. All materials are not Abrasion Resistance (Ha) (C241) ...3.0-33.0
suitable for all uses. In order to avoid mistaken Recommended (min): 10
selections, tests for material values should be
made prior to final material selection. 2.0 STRENGTH (ASTM C99,
C170, C880)
1.6 Physical Properties of Limestone.
(This historical data and information are 2.1 Values for modulus of rupture,
provided only as a guideline. Recommended compressive strength, and flexural strength are
minimums or maximums are established and ascertained by testing specimens of limestone
provided by ASTM International.)4 under laboratory conditions until they fail.

Property Range of Values 2.2 Size and finish of test samples required
Compressive Strength (C170) by the standard ASTM test methods may not
lbs/in² ............................. 1,600-32,000 reflect the actual performance of stone when
Recommended (min): used in lesser thicknesses or with other finishes
1,800 (low density), that affect strength. For this reason, the
4,000 (medium density), Modulus of Rupture (C99) test is
8,000 (high density) recommended when the stone to be used will

4 Test methods described in current ASTM 5 Also known as Young’s Modulus.

standards.
Page 6-12 • Limestone  2016 Marble Institute of America
be two or more inches thick. The Flexural ASTM C241 tests, are recommended for use as
Strength (C880) test is recommended when flooring exposed to normal foot traffic. A
the stone thickness will be less than two inches. minimum abrasive hardness of 12 is
recommended for commercial floors, stair
2.3 The strength of a limestone is a measure treads, and platforms subject to heavy foot
of its ability to resist stresses. There are several traffic. If floors are constructed with two or
varieties in the limestone group, including more stone varieties, the Ha values of the
calcarenite, coquina, dolomite, micro- stones must not differ by more than 5, or the
crystalline, oolitic, travertine, and re- floor surface will not wear evenly and
crystallized. Their strength depends on several uniformly.
factors, such as the rift and cleavage of the
calcite crystals, the degree of cementation, the 5.0 FACTORS AFFECTING
interlocking of the calcite crystals, and the
PROPERTIES
nature of any cementing materials present.
5.1 The ultimate test of a building material
3.0 FIRE RESISTANCE is its ability to have and maintain the necessary
structural strength, as well as beauty of
3.1 Stone is not combustible according to appearance and low cost of maintenance over
underwriters’ ratings, and therefore is the useful life of the structure. Experience has
considered a fire-resistant material. Because of proven that limestone meets this test as few
its thermal conductivity, heat transfer is fairly other building materials can. Studies have
rapid. Most stone is not considered a highly shown that the durability of most limestones is
rated thermal insulator. little affected by cycles of weather. This is
because most have a low rate of moisture
3.2 Underwriters’ fire-resistance ratings absorption.
evaluate whether or not a material will burn,
as well as how long it will keep surrounding 5.2 Limestone exterior paving is not
combustible materials from reaching recommended for environments where de-
temperatures which will cause them to ignite. icing chemicals may be used to melt ice and
Methods of estimating fire resistance periods of snow because these chemicals will damage
masonry walls and partitions utilizing most limestone.
component laminae are given in “Fire
Resistance Classifications of Building 5.3 Exteriors of gray or black limestones
Construction,” BMS92, National Bureau of with a bituminous or carbon composition
Standards. should be avoided as the action of atmosphere
agents will rapidly cause the surface to
4.0 ABRASION RESISTANCE deteriorate.
(ASTM C241)
6.0 SAFETY FACTORS
4.1 Abrasion resistance is a property of
stone that should be tested per ASTM C241 to 6.1 Good engineering practice requires that
provide an indication of the stone’s wearing allowable design stress must provide a margin
qualities when exposed to foot traffic. of safety in any structural element. As a
necessary precaution against such conditions as
4.2 The hardness and uniform wearing wind, ice, snow, impact, temperature changes,
qualities of most limestones make them and imperfect workmanship, these allowable
extremely desirable and economically practical stresses must be smaller than those which
for floors and stairs. Varieties with an abrasive produce failure.
hardness (Ha) of 10 or more, as measured by

 2016 Marble Institute of America Limestone • Page 6-13

6.2 For a particular construction, the closer 8.0 EFFLORESCENCE AND
the allowable load is to the ultimate failure STAINING
load, the more efficient is the use of the
material and the less the cost of the 8.1 Efflorescence is a salt deposit, usually
construction. white in color that occasionally appears on
exterior surfaces of masonry walls. The
6.3 Contemporary building design does not efflorescence-producing salts found in masonry
usually employ stone as part of the structural are usually sulfates of sodium, potassium,
frame, but rather as an independent unit, a magnesium, calcium, and iron. Salts which are
curtain wall, or veneer. Therefore, the chlorides of sodium, calcium, and potassium
primary concern in such cases is with wind or will sometimes appear, but they are so highly
seismic loads, and a safety factor of 8.0 is soluble in water that they will be washed off by
recommended. Where the stone is to be rain.
subjected to concentrated loading, such as stair
treads or lintels supported only at the ends, a 8.2 The water-soluble salts causing
factor of 10.0 should be used. These safety efflorescence come from other materials in the
factors may be adjusted using sound wall. The salts exist in small amounts and are
engineering principles and judgment. leached to the surface by water percolating
through the walls. The most feasible means of
6.4 As buildings become taller and prevention is to stop the entrance of large
individual stone-slab veneer becomes larger in amounts of water. Absorption from the face
area, the lateral forces due to wind loads must will not cause efflorescence unless there are
be considered. Wind tunnel tests are often open joints.
used on major structures to determine wind
dynamics and force magnitude. Reinforcement 8.3 Limestone is seldom injured by
is sometimes necessary for large dimension slab efflorescence. However, some of the salt
veneer in critical areas. crystals may form in the pores near the surface.
Crystal growth (recrystallization) in the pores
7.0 SEISMIC CONSIDERATIONS can cause stress on the walls of the pores and
cause the stone to flake off. If the conditions
7.1 Seismic considerations generally require bringing about this action persist, scaling may
that low buildings be stiff, and that tall continue and flake off one layer after another.
buildings be relatively flexible. Design of For this to happen, large amounts of water
connections must account for seismically must enter the wall and must contain large
induced horizontal loading. Local building amounts of salts.
codes vary and must always be checked to
determine specific requirements for each area. 8.4 Staining or discoloration occurring on
The National Bureau of Standards has published new buildings can be a brown stain found on
two documents on the topic: “Earthquake buff limestone, or a dark gray stain on gray
Resistant Masonry Construction,” NBS Science limestone. Research indicates that the stains
Series 106; and “Abnormal Loading on are caused by the action of water percolating
Buildings and Progressive Collapse: An through cement from which soluble alkali salts
Annotated Bibliography,” NBS Science Series are leached. The salts are then carried through
67. The U.S. Army Corps of Engineers has also the stone, where partially oxidized organic
published TM 5-809-10, “Seismic Design for matter is picked up. This is then transported to
Buildings.” the surface of the stone, where it is deposited
as a stain as evaporation of the water takes
place.

Page 6-14 • Limestone  2016 Marble Institute of America

8.5 This staining phenomenon is similar to
efflorescence except that it involves organic
material. It does not harm the stone other than
leaving an objectionable appearance during or
soon after erection. However, if left alone, the
stain is removed naturally by the action of the
elements, usually in the course of a few
months.

8.6 A considerable amount of water passing

through the stone is necessary to bring out
conspicuous discolorations. Proper pre-
cautions taken during construction of the walls
will usually prevent such troubles. A simple
and helpful expedient is to provide frequent
weep holes in the base course and above shelf
angles. These should be placed in the vertical
joints so they can be sloped upward from the
front to back.

8.7 Stains sometimes appear on the base

course when limestone is in contact with soil,
due to the carrying of soluble salts and some
colored soil constituents up through and to the
surface of the stone by capillary action. Almost
all soils contain soluble salts. Therefore, this
staining phenomenon should disappear when
the source of moisture is eliminated.

8.8 Avoid contact between soil and stone.

Dampproofing treatments of either a
bituminous or cementitious nature may be
used as a barrier to the ground water or
construction moisture causing these stains.

9.0 THERMAL EXPANSION

9.1 The thermal expansion of limestone is

an important consideration where limestone is
used with dissimilar materials to form large
units that are rigidly fixed.

9.2 The coefficient of thermal expansion

varies from one variety to another; actual
thermal characteristics of a specific limestone
should be obtained from the Quarrier or
Fabricator before making a final selection.

 2016 Marble Institute of America Limestone • Page 6-15

NOTES:

Page 6-16 • Limestone  2016 Marble Institute of America

MARBLE and onyx 1.2.3.3 Additional publications may be
available from the MIA Bookstore. Go online
at www.marble-institute.com.
1.0 GENERAL
1.3 Scope of Included Work
1.1 Related Documents
1.3.1 The work to be completed under this
1.1.1 Drawings and general provisions, contract includes all labor and materials
including General and Supplementary required for the furnishing and installation of
Conditions of the Contract and Division I all marble work shown or called for on the
Specification sections, apply to this section. contract drawings, specifications, and
addenda.
1.2 Applicable Publications
1.4 Definition of Terms
1.2.1 The following publications listed here
and referred to thereafter by alphanumeric 1.4.1 The definitions of trade terms used in
code designation only, form a part of this this specification shall be those published by the
specification to the extent indicated by the MIA or ASTM International.
references thereto:

1.2.2 ASTM International (ASTM):

1.5 Source of Supply

1.2.2.1 C503, Standard Specification for 1.5.1 All marble shall be obtained from
Marble Dimension Stone (Exterior) quarries having adequate capacity and facilities
to meet the specified requirements, and by a
1.2.2.2 C97, Standard Test Methods for firm equipped to process the material promptly
Absorption and Bulk Specific Gravity of on order and in strict accord with
Dimension Stone specifications. The Specifying Authority
(architect, designer, engineer, contracting
1.2.2.3 C99, Standard Test Method for officer, end user, etc.) reserves the right to
Modulus of Rupture of Dimension Stone approve the Material Supplier prior to the
award of this contract. Stone and workmanship
1.2.2.4 C170, Standard Test Method for quality shall be in accordance with Industry
Compressive Strength of Dimension Stone Standards and Practices as set forth by the MIA.

1.2.2.5 C241, Standard Test Method for 1.6 Samples

Abrasion Resistance of Stone Subjected to Foot
Traffic 1.6.1 The Marble Contractor shall submit
through the General Contractor, for approval
1.2.2.6 C880, Standard Test Method for by the Specifying Authority, at least two sets of
Flexural Strength of Dimension Stone samples of the various kinds of marble
specified. The sample size shall be 1'-0" x 1'-0"
1.2.3 Marble Institute of America and shall represent approximately the finish,
(MIA): texture, and anticipated range of color to be
supplied. Where necessary to show variations
1.2.3.1 Membership, Products, and Services in color and markings, larger samples or range
Directory sets of samples should be submitted. If marble
is to be matched, a minimum of two sets each
1.2.3.2 Dimension Stone Design Manual containing four matched samples showing
proposed veining and range of color in each set

 2016 Marble Institute of America Marble and Onyx • Page 7-1

must be supplied. Samples designating finished Marble Contractor, including the services of an
face shall be clearly labeled on the back with Engineer, if required, for the establishment of
the name of the marble, the group classification levels, bench marks, and the like. The Marble
for soundness, and the use for which the Contractor shall not be responsible for
marble is intended. One set of samples shall be determining, making, or verifying (1) design,
retained by the Specifying Authority, and one structural, wind, seismic, or other design
set shall be returned to the Marble Supplier for loads; (2) engineering estimates; (3) plans or
his/her record and guidance. It is noted herein specifications; or (4) the types, sizes, or
that marble is a natural material and will have locations of anchors, unless specifically added
intrinsic variations in color, markings, and to the scope of work.
other characteristics. Depending on the marble
selected and quantity required, a range 1.8 Defective Work
mockup may be used to further define the
characteristics of the material. Cost of 1.8.1 Any piece of marble or onyx showing
mockup, if required, shall not be included in flaws or imperfections upon receipt at the
this section. storage yard or building site shall be referred to
the Specifying Authority for determination as
1.6.2 Prior to fabrication, an inspection and to responsibility and decision as to whether it
approval by the Specifying Authority and/or shall be rejected, patched, or redressed for use.
General Contractor and/or End User of the
finished slabs is recommended to understand 1.9 Repairing Damaged Stone
the finish and full range of the material.
1.9.1 Small chips at the edges or corners of
1.7 Shop Drawings marble may be patched provided the structural
integrity of the stone is not affected and the
1.7.1 The Marble Contractor shall submit patch matches the color and finish of the
through the General Contractor, for approval marble so that the patch does not detract from
by the Specifying Authority, sufficient sets of the stone’s appearance.
shop drawings showing general layout,
jointing, anchoring, stone thickness, and such
other pertinent information. These drawings
2.0 MATERIALS
shall show all bedding, bonding, jointing, and
anchoring details along with the net piece
dimensions of each marble unit. One copy of 2.1 Marble
approved drawings shall be retained by the
Specifying Authority, one copy shall be 2.1.1 General: All marble shall be of kind or
retained by the General Contractor, and one kinds shown on the Architect's drawing or as
copy returned to the Marble Contractor for specified herein, conforming to or within the
fabrication. NO FABRICATION OF MARBLE range of approved samples and in accordance
SHALL BE STARTED UNTIL SUCH with the characteristics and working qualities
DRAWINGS HAVE BEEN FULLY set forth under their respective Soundness
APPROVED AND MARKED AS SUCH. The Group Classifications, A, B, C, or D, as defined
General Contractor shall furnish all field by the Marble Institute of America. Care shall
dimensions necessary for fabrication. If be taken in selection to produce as harmonious
measurements are not established and effects as possible. Patching and waxing, where
guaranteed in advance, the Marble Contractor permitted under the Marble Institute of
shall obtain and verify measurements at the America Group Classifications, shall be
building. The General Contractor shall be carefully done to conform to the marble’s
responsible for all reasonable assistance to the general character and finish. Texture and finish

Page 7-2 • Marble and Onyx  2016 Marble Institute of America

shall be within the range of sample(s) approved stain the finished work, and shall be screened
by the Specifying Authority. as required for the desired results.

2.1.1.1 ASTM C503 [C97] [C99] [C170] 2.2.3 Portland cement shrinkage-
[C241] [C880] See the chart of applicable reducing accelerator used with portland
ASTM standards and tests in the Appendix. cement to give it the quick-setting
characteristics of plaster of paris, shall be a
2.1.2 Schedule: Marble shall be provided nonstaining admixture that will not corrode
as follows: anchors or dowels.

2.1.2.1 For (state location on building) (state 2.2.4 Nonstaining adhesive shall be of a
name and color) marble with a (type) finish, type that will not stain the marble, that is not
supplied by (name company or list several approved affected by temperature changes or moisture,
suppliers). and that adheres with strong suction to all clean
surfaces.
2.1.2.2 Provide information as in (1) for
each different marble/finish combination in 2.3 Pointing Mortar
the project.
2.3.1 Mortar for pointing shall be Type N, as
2.1.3 Finishes: Finishes listed in the defined in ASTM C270 (Standard Specification
schedule shall conform with definitions by MIA for Mortar for Unit Masonry). All mixing,
or ASTM International. handling, and placing procedures shall be in
accordance with ASTM C270.
2.1.3.1 Polish Finish: A mirror-like, glossy
surface which brings out the full color and 2.4 Sealants and Backup
character of the marble. This finish is not
Material (If Applicable)
recommended for exterior or commercial
floor use.
2.4.1 Where specified (state type or name of
sealant) shall be used for the pointing of joints.
2.1.3.2 Honed Finish: A velvety smooth
The backup material used with the sealant shall
surface with little or no gloss.
be (identify material).
2.1.3.3 Abrasive Finish: A flat, nonglossy
2.4.2 Sealants, used for pointing to exclude
surface usually recommended for exterior use.
moisture and provide a joint that will remain
plastic for many years, shall be nonstaining.
2.2 Setting Mortar (And
Adhesives) 2.5 Anchors, Cramps, and
Dowels
2.2.1 Portland cement shall conform to the
requirements of the Standard Specifications for
2.5.1 Anchors, cramps, and dowels shall be
Portland Cement, ASTM C150. White
made of corrosion-resistant metals. Special
portland cement is recommended for white or
cramps, dowels, and the like shall be used
light colored marble. Nonstaining cement shall
where shown on shop drawings, but
conform to the requirements of the Standard
elsewhere, #8 copper or stainless steel wire
Specifications for Masonry Cement, ASTM
anchors shall be used. It shall be the
C91.
responsibility of the Marble Contractor to
anchor all marble securely. For standing
2.2.2 Sand. All sand shall be clean, free from
marble, the following practices usually prevail:
organic and other deleterious matter likely to

 2016 Marble Institute of America Marble and Onyx • Page 7-3

2.5.1.1 A minimum of four anchors should 3.4.2 Maintain a minimum of 1" between
be provided for pieces up to 12 square feet, stone backs and adjacent structure. (Note:
with two additional anchors for each additional many bolted connections will require more
8 square feet of surface area. Shims used to space than this; 2" space may be more
maintain joints shall be plastic. desirable. Large-scale details should illustrate
and control these conditions.)
2.5.1.2 Use of copper wire for anchors to be
installed over 12' off the ground is not 3.5 Cutting for Anchoring,
recommended. Supporting, and Lifting Devices
3.0 FABRICATION 3.5.1 Holes and sinkages shall be cut in stones
for all anchors, cramps, dowels, and other
3.1 Beds and Joints tieback and support devices per industry
standard practice or approved shop drawings.
3.1.1 Bed and joint width shall be determined However, additional anchor holes shall be
by analysis of anticipated building movements drilled at job site by Marble Contractor to
and designed to accommodate such facilitate alignment.
movements without inducing undue stresses in
the stone panels or joint filler materials. 3.5.2 No holes or sinkages will be provided
Expansion joints shall be designed and located for Marble Contractor’s handling devices
to accommodate larger movements. unless arrangement for this service is made by
the Marble Contractor with the Marble
3.2 Backs of Pieces Fabricator.

3.2.1 Backs of pieces shall be sawn or roughly (NOTE: It is not recommended that lewis pins
dressed to approximately true planes. Back be used for stones less than 3½" thick.)
surfaces shall be free of any matter that may
create staining. 3.6 Cutting and Drilling for
Other Trades
3.3 Moldings, Washes, and Drips
3.6.1 Any miscellaneous cutting and drilling
3.3.1 Moldings, washes, and drips shall be of stone necessary to accommodate other
constant in profile throughout their entire trades will be done by the Marble Fabricator
length, in strict conformity with details shown only when necessary information is furnished
on approved shop drawings. The finish quality in time to be shown on the shop drawings and
on these surfaces shall match the finish quality details, and when work can be executed before
of the flat surfaces on the building. fabrication. Cutting and fitting, due to job site
conditions, will be the responsibility of the
3.4 Back-Checking and Fitting Marble Contractor.
to Structure or Frame
3.6.2 Incidental cutting such as for window
3.4.1 Stone coming in contact with structural frame clips, etc., which is normally not
work shall be back-checked as indicated on the considered to be the responsibility of the Stone
approved shop drawings. Stones resting on Supplier, will be provided only by arrangement
structural work shall have beds shaped to fit the by the General Contractor and Marble
supports as required. Contractor with the Marble Fabricator.

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3.7 Carving and Models 5.1.3 Marble and onyx shall be free of any
ice or frost at time of installation. Salt shall not
3.7.1 All carving shall be done by skilled Stone be used for the purpose of melting ice, frost, or
Carvers in a correct and artistic manner, in snow on the stone pieces.
strict accordance with the spirit and intent of Adequate protection measures shall be taken to
the approved shop drawing, or from models ensure that exposed surfaces of the stone shall
furnished or approved by the Specifying be kept free of mortar at all times.
Authority.
5.2 Mortar Setting of Marble
and Onyx
4.0 SHIPPING AND HANDLING
5.2.1 Floor Marble
4.1 Packing and Loading
5.2.1.1 Floor Preparation. It is the
4.1.1 Finished marble shall be carefully General Contractor’s responsibility to clean all
packed and loaded for shipment using all subfloor surfaces to remove dirt, dust, debris,
reasonable and customary precautions against and loose particles immediately prior to setting
damage in transit. No material which may marble floor and to ensure that the area to
cause staining or discoloration shall be used for receive the stone flooring meets the deflection
blocking or packing. standards of the industry.

4.2 Site Storage 5.2.1.2 Curing Compounds. Curing

compounds of any kind shall not be used on the
4.2.1 It shall be the responsibility of the slab on which floor marble is to be directly set.
Marble Contractor to receive, store, and If a curing compound is present, it is the
protect the marble from damage by others after General Contractor’s responsibility to remove
it is delivered to the job site and prior to its it by scarifying the slab.
erection in the building. All marble shall be
received and unloaded at the site with care in 5.2.1.3 Before being set, all marble shall be
handling to avoid damage or soiling. If marble clean and free of foreign matter of any kind.
is stored outside, it shall be covered with
nonstaining waterproof paper, clean canvas, or 5.2.1.4 Mortar Bed. The mortar bed to
polyethylene. receive the marble tile shall consist of 1 part
portland cement to not more than 4 to 5 parts
of clean, sharp sand mixed quite dry for
5.0 INSTALLATION tamping. White portland cement is
recommended for light-colored marbles.
5.1 General Installation
5.2.1.5 Marble Tamped. The marble shall
5.1.1 Installation shall be accomplished with be tamped with a suitable mallet until firmly
competent, experienced Stone Setters, in bedded to the proper level of the floor.
accordance with the approved shop drawings.
5.2.1.6 Marble Removed. The marble
5.1.2 All marble and onyx pieces shall be shall then be removed and the back parged with
identified with a unique piece number wet cement or the bed sprinkled with water
corresponding with the number on the shop and cement. In the latter procedure, the back
drawings. Interchanging of numbered pieces is of the marble shall be wet. The method of fully
not permitted.

 2016 Marble Institute of America Marble and Onyx • Page 7-5

buttering edges of the marble as it is laid is corners and edges of stone tiles must always be
equally approved. fully supported, and contact shall always be
100% in exterior and/or water-susceptible
5.2.1.7 Joints. Joints between the marble conditions.
pieces shall show an even width when laid and
finished. 5.2.2 Interior Veneer Marble

5.2.1.8 Traffic after Installation. The 5.2.2.1 The marble shall be set by spotting
floor shall be roped off for 24 hours after with cement mortar and the use of concealed
installation and then grouted with water and anchors secured in the wall backing.
white portland cement grout or nonstaining
dry set portland cement grout. 5.2.3 Marble Wall Tile

5.2.1.9 Timeline for Additional 5.2.3.1 Individually set thin tile (nominal
Cleaning. Cleaning or additional surfacing, if 3/8" thick) on vertical surfaces exceeding 15'-
required, shall not be undertaken until the new 0" is not recommended. Where thin marble
floor is at least seven days old. tile is installed, nonstaining adhesives or thin-
set mortars may be used as setting beds.
5.2.1.10 Thin-set Method. The thin set
method of installing marble tile employing the 5.2.4 Toilet and Shower
use of dry-set portland cement mortars is Compartments
recommended for thin marble tiles (nominal
3/8" thick) where optimum setting space is not 5.2.4.1 Stiles and partitions shall be
available. Subfloor shall be clean, smooth- assembled with concealed dowel fastenings or
finished, and level. corrosion-resistant angles, three in height of
stall.
5.2.1.10.1 Stone dust must be washed off the
back face of stone pavers prior to installation. 5.2.4.2 For ceiling-hung units, metal
Apply mortar with flat side of trowel over an supporting members in ceiling are to be
area that can be covered with tile while mortar furnished and installed by the General
remains plastic. Within ten minutes, and using Contractor.
a notched trowel sized to facilitate the proper
coverage, comb mortar to obtain an even- 5.3 Mortar Joints
setting bed without scraping the backing
material. Key the mortar into the substrate 5.3.1 Mortar joints shall be raked out to a
with the flat side of the trowel. Comb with the depth of ½" to ¾". Apply pointing mortar in
notched side of the trowel in one direction. layers not exceeding 3/8" and allow each layer
Firmly press stone tiles into the mortar and to get hard to the touch before the next layer is
move them perpendicularly across the ridges, applied. Tool finished joints with a concave
forward and back approximately 1/8"to ¼" to tool having a diameter approximately 1/8"
flatten the ridges and fill the valleys. Ensure a greater than the joint width.
maximum mortar thickness of 3/32" between
stone tile and backing after stone tile has been 5.3.2 Care shall be taken to keep expansion
tamped into place. Stone tile shall not be joints free of mortar, which would
applied to skinned-over mortar. Alternatively, compromise their function.
back butter the stone tiles to ensure 100%
contact. In either method, ensure 100%
contact on 3/8" tile; not less than 80% contact
on ¾" or thicker material, noting that all

Page 7-6 • Marble and Onyx  2016 Marble Institute of America

5.4 Anchorage 5.7.2 All sealants shall be tooled to ensure
maximum adhesion to the contact surfaces.
5.4.1 All marble shall be anchored or doweled
in accordance with the approved shop 5.8 Weep Tubes
drawings.
5.8.1 Plastic or other weep tubes shall be
5.4.2 To the furthest extent possible, all placed in joints where moisture may
anchor preparations in the marble units shall be accumulate within the wall, such as at base of
shop-applied. cavity, continuous angles, flashing, etc., or as
shown on architectural drawings.
5.4.3 All anchorage devices and anchor
hole/slot fillers shall be in accordance with
ASTM C1242. Care must be taken to ensure
6.0 CLEANING AND
that any holes capable of retaining water are
filled after use to prevent water collection and PROTECTION
freezing.
6.1 Cleaning
5.5 Sealant Joints
6.1.1 Marble shall be shop cleaned at the time
5.5.1 Where so specified, joints requiring of final fabrication. It shall also be cleaned after
sealant shall be first filled with a closed-cell installation and all pointing or caulking is
ethafoam rope backer rod. The backer rod completed. All dirt, excess mortar, weld
shall be installed to a depth that provides splatter, stains, and other defacements shall be
optimum sealant profile after tooling. removed.

5.5.2 If recommended by the Sealant 6.1.2 All cleaning methods shall be in

Manufacturer, primers shall be applied to the accordance with ASTM C1515.
substrate surfaces according to the
manufacturer’s directions prior to application 6.1.3 Stiff bristle fiber brushes may be used,
of the joint sealant. but the use of wire brushes or of acid type
cleaning agents and other solutions which may
cause discoloration is expressly prohibited.
5.6 Expansion Joints
Fabricator should be contacted before cleaners
other than neutral detergents are used.
5.6.1 It is not the intent of this specification to
make control or expansion-joint
recommendations for a specific project. The 6.2 Protection of Finished Work
Specifying Authority must specify control or
expansion joints and show locations and details 6.2.1 After the marble work is installed, it
on drawings. shall be the responsibility of the General
Contractor to see that it is properly and
adequately protected from damage or stains
5.7 Caulking
until all trades are finished. This responsibility
includes the stone cleaning costs prior to the
5.7.1 Where so specified, joints shall be
required final inspection. The Marble
pointed with the sealant(s) specified in Section
Contractor will outline the needs for
2.4, after first installing the specified backup
protection, in writing, to the General
material and applying a primer if required, all
Contractor. For the protection of projecting
in strict accordance with the printed
members, corners, window stools, and
instructions of the Sealant Manufacturer.
saddles, wood guards using lumber that will

 2016 Marble Institute of America Marble and Onyx • Page 7-7

not stain or deface with marble shall be certain types of limestone that take a polish and
supplied, installed, and maintained by the can be used as architectural or ornamental
General Contractor. All nails used shall be stone2. The dimension stone industry
galvanized or nonrusting. Damage to finished traditionally includes other types of stone, such
marble by other trades shall be repaired or as onyx, in the same classification as marble.
replaced at the expense of the General
Contractor. Marble flooring shall be 1.1.2 Almost all metamorphic marbles are
adequately protected by the General developed by high pressures in the process of
Contractor against traffic and other damage metamorphism, while recrystallization of
with nonstaining materials without cost to the limestone can occur under normal overburden
Marble Contractor. pressures in thick sedimentary sequences.
Obviously, due to the high pressures of
6.2.2 All marble work in progress shall be metamorphism, it is expected that
protected at all times during construction by metamorphic marble is tighter, denser, and
use of a strong, impervious film or fabric more fracture-free than other kinds of marble,
securely held in place. and generally that is true. Metamorphic marble
and recrystallized limestone will not be
differentiated in the remainder of this discourse
unless otherwise noted.
PRODUCT
DESCRIPTION – 1.1.3 In commercial usage, descriptives may
be added that refer to a marble’s color, e.g.,
Marble and Onyx white or blue marble. More useful to the trade
because of the necessity to judge the properties
1.0 GEOLOGICAL and behavior of the stone, is the scientific
CLASSIFICATION convention of referring to the mineralogical
content of the stone, such as dolomitic marble
1.1 Marble is geologically defined as a or sandy marble, indicating marbles with some
metamorphic rock predominately consisting of dolomite or sand content. Assuming the
fine- to coarse-grained, recrystallized calcite marble user knows something about the
(CaCO3), and/or dolomite, (CaMg(CO3)2), properties of the minerals, an idea of the
which has a texture of relatively uniform stone’s behavior can be anticipated.
crystals ranging from very large (inches) to
very fine, small, uniform sized crystals1. Two 1.1.4 Colors. In dolomitic marble, the
aspects of the definition are important to the dolomite often weathers to a tan or buff color
stone industry professionals and scientists from the oxidation of a slight amount of iron
alike: It is metamorphic and, it is recrystallized; released from the marble. The chemical series
that is, many marbles are formed by processes of dolomite, with the end members of
of recrystallization and/or metamorphism and CaMg(CO3)2 to CaFe(CO3)2 is continuous
have recrystallized textures that obscure most from 100% Ca to 100% Fe, so many dolomitic
previous texture and depositional features. marbles, while nearly white when cut, will
probably weather slightly buff to tan due to the
1.1.1 A commercial definition equally release of iron, which then oxidizes to iron
important and long used in the industry is that oxides that yield the characteristic colors from
marble is any crystallized carbonate rock and off-white to tan, buff, yellow to red, and dark

1 Adapted from: Bates, R. L. and J. A. Jackson, eds.,

1980, Glossary of Geology, 2nd Edition, American
Geological Institute, 1980.
2 Ibid.

Page 7-8 • Marble and Onyx  2016 Marble Institute of America

brown to the stone as a whole. In dolomitic Original sediment usually has a matrix of
marble these colors are often uniformly organically derived, clay-sized carbonate grains
distributed. Bands, streaks, or swirls of distinct of aragonite. If buried, compacted, and
color may have other explanations relating to cemented, it takes about 50 to 60 million years
the stone’s original deposition and subsequent under standard conditions of temperature and
geological formation. pressure for aragonite to convert to calcite. In
addition to fossils, other features, artifacts of
1.1.5 Calcite, the dominant mineral of deposition, may also be preserved. Examples
marble, occurs in many colors. Among the include voids, often the internal void space of
many common trace-amount impurities that shells of clams and snails. Commonly, these are
color marbles are organic matter (generally filled in with carbonate dust that has
gray to black), chlorite3 (generally light green crystallized solid. Voids of any origin
to yellowish-green), epidote4 (the same green commonly contain calcite crystals totally filling
as above), and minor amounts of land-derived in the void space.
clays, silts, and sands. These clastic silicate
sediments may already be stained with iron to 1.1.8 Cross-bedding and ripple marks on the
yield any color from very light buff to dark sea floor are visibly preserved, as are raindrop
brown, and almost any red color; or the silicate imprints and mud cracks from shrinkage during
grains themselves may contain trace amounts exposure and drying that form if the surface is
of iron available by chemical release to stain exposed to air, for example at low tide, and
and color. Other known coloring agents are then buried, preserving the features. There are
too numerous to mention here. Iron is by far many more examples, some of which are called
the most common. “faults,” but are entirely natural. Most of these
features formed at the time of deposition
1.1.6 Impurities are often confused with other disappear and are lost in the recrystallization
features that can be found in marble, most of process of limestone or in pressure-related
which are primary depositional features5 or metamorphism. Some of these primary
artifacts of chemical changes prior to, during, features can be detrimental, as they could
or subsequent to metamorphism and/or re- weaken stone.
crystallization. Such features are intrinsic to the
character of many exotic marbles, making 1.1.9 Another kind of feature, known as a
some rare types quite valuable. Conversely, stylolite, is formed as a result of geochemical
the same features could be detractions, processes either after burial or cementation
weakening the stone or making it unattractive, and long geologic aging. A stylolite is a spiked
thus rendering it unsuitable as a decorative surface within and usually parallel or
dimension stone. subparallel to a bedding planes. Stylolites are
evidence of dissolution along fractures or
1.1.7 Geological origin. Limestone that partings, possibly initiated by a thin film of dark
begins as an accumulation of shelly debris, organic matter. Such dissolution can remove
mostly fragmental but also including whole several feet of section in a carbonate sequence.
shells, is mostly the aragonite form of CaCO3. These lines become increasingly irregular in a

3 Chlorite is a very complex hydrous silicate of aluminum. Being very hard, heavy, and insoluble, it
magnesium, iron, and aluminum has a platy habit. It is weathers out of metamorphic terrain and can be
soft, flexible (micalike, but not elastic), and usually an deposited in near-shore marine deposits of carbonate
alteration product in igneous or low-grade debris, lending its green color to marble.
metamorphic stone, or is transported into sedimentary 5 Primary depositional features are developed at the time

sequences. of deposition of sedimentary particles.

4 Epidote is often found with chlorite and has about the

same color range. It is a complex, low-grade,

metamorphic hydrous silicate of iron, calcium, and

 2016 Marble Institute of America Marble and Onyx • Page 7-9

vertical plane as dissolution proceeds at varying marble is in contact with, or influenced by
rates from place to place along the surface. other complex metamorphic stone, then it may
Stylolites can occur in any carbonate rock from have complex carbonate/metamorphic
limestone to metamorphic marble, and are minerals other than the few already
purely a phenomenon of chemical dissolution. mentioned. It is geologic factors like these that
Stylolites are identifiable as a thin, spiky, or can produce the highly colorful and complex
crenellated black line. marbles seen in both antique and modern
works. Such stones may occur in limited
1.1.10 Other minerals found in marbles deposits. The more common and universally
include the various common carbonate used marbles from antiquity to the present are
minerals previously mentioned. One, mostly calcite, many close to ±99% calcium
magnesite (MgCO3), is characteristic of the carbonate, found in large deposits with
metamorphic marbles and not usually found in adequate reserves for extended quarrying.
recrystallized, limestone-type marbles. A
generally undesirable mineral, pyrite (FeS2) or 1.1.13 The great variety of colorful, often
iron sulfide may also occur in marble and are exotic marbles from Italy is formed in
alteration minerals formed after deposition and juxtaposition to intrusive and extrusive igneous
during the metamorphism and recrystallization rocks and/or a variety of metamorphics. Italy
phase from small amounts of entrained sulfates has an exceedingly complex geology, with
or fluids containing dissolved, sulfur-bearing active igneous activity and nearly every known
salts that enter the stone during its burial level of metamorphism, as well as a variety of
history. sedimentary deposits. Italy also has
experienced remarkable dry periods clearly
1.1.11 Pyrite will occur as discrete cubic indicated by the kinds of sedimentary rocks
crystals, finely disseminated, or as masses in surrounding the Mediterranean (e.g., mottled
marble. It is hard (H=6+ on the Mohs scale6 ) red marbles), dating from when the area was
and sometimes has an attractive, brassy an empty, desert-like basin before the Straits of
appearance–it will bleed ugly stains from Gibraltar opened to flood the present
oxidation during repeated water incursion. Mediterranean Sea.
Pyrite is often found disseminated throughout
shelly limestone, a natural occurrence with 1.1.14 Physical and Chemical
biological materials deposited in anoxic Properties of Calcite. To understand the
conditions (without oxygen). Pyrite exposed stone, one must first understand the minerals.
on the face of cut and polished stone easily Many of the desirable qualities and many of the
reacts with moisture to form the undesirable problems commonly encountered with marble
and difficult to remove staining. Its brassy are direct consequences of the properties of
metallic luster is not necessarily unattractive, calcite, the dominant mineral, or in some
but not for use in wet environments. cases, the less abundant accessory minerals. A
review of the physical and chemical properties
1.1.12 The accessory mineral variation of calcite follows:
found in marble is diverse and dependent on
the geologic origin and burial history of the 1.1.14.1 Crystals. Calcite crystals are found
limestone or marble. If the marble was in in several different and predictable crystal
contact with granite or volcanic igneous rock, shapes exactly controlled by atomic geometry
then the accessory minerals may include a suite of the CaCO3 molecule. Crystals may grow in
of complex carbonates and silicates. If the isolated free spaces or voids called “vugs7” or in

6See Appendix for the Mohs Scale of mineral hardness. limestone, dolomite, or marble may contain crystals of
7Vugs are mostly small to microscopic, but some have calcite in addition to some of the other mentioned
been found large enough to walk into. A vug in accessory minerals.

Page 7-10 • Marble and Onyx  2016 Marble Institute of America

open fractures or in masses like an entire have limited longevity in sunlight and thus fade
sequence of stone. More geometrically in time. Or these manmade dyes wash out
complex crystals, if they occur, are generally from chemical spills and ordinary cleaning
unrecognizable from randomly oriented cuts compounds. Dyed stone of any kind should be
on polished marble surfaces. Both fractures and considered with extreme caution for these
vugs eventually fill completely with crystals, reasons.
often obscuring their former existence. The
most common calcite crystal shapes are 1.1.14.4 Composition. Calcite is a
parallelograms or truncated, faceted, or carbonate of calcium or CaCO3. While calcite
tapering prisms8. Fractures are generally is the most abundant component, carbonates of
identifiable even if filled, while a totally infilled iron, manganese, magnesium, zinc, and
vug is easily overlooked. Fractures may be a strontium are sometimes present. Many other
potential line of breakage, but a small, closed carbonates and hydrous carbonate minerals of
vug, being virtually unrecognized on a polished various metals such as lead, barium, and copper
surface, is of little significance to the are rarely seen in commercial marble.
commercial quality of a stone.
1.1.14.5 Acid Reaction. Calcite
1.1.14.2 Cleavage. Calcite has a definite effervesces—reacts and bubbles vigorously in
geometric molecular structure; i.e., the atoms dilute hydrochloric acid. This is a positive
of calcium, oxygen, and carbon are always diagnostic chemical property of calcite. Calcite
arranged in a fixed geometry such that three can dissolve without visible bubbling in the
planes of weakness occur not at 90°, along presence of other kinds of dilute acids or even
which calcite crystals will generally break.9 acidic liquids, such as red wine and salad
The result is a parallelogram-shape fragment vinegars. In acidic atmospheres with sulfur,
with very flat sides. This is termed cleavage. It marble is not only etched, but will react with
reflects atomic planes of weakness that very dilute sulfuric acid in moist air to form a
predetermine how and where a mineral will powdery calcium sulfate, the mineral gypsum.
break apart. Other minerals may have one, to
as many as six, cleavages. Any two exactly 1.1.14.6 Optical Character. Optically clear
parallel sides constitute one cleavage. Thus, a cleavage fragments–parallelograms–of calcite
six-sided parallelogram of calcite exhibits three have the curious optical property of double
cleavages, with one for each pair of parallel refraction. Objects or print seen through the
sides. A cleavage face is very flat. It may be cleavage fragment will appear as a double
stepped but the stepped surfaces are exactly image. The varietal name for optically clear
parallel and reflect light as a single surface. calcite is Iceland Spar10.

1.1.14.3 Color. Calcite can be any color from 1.1.14.7 Anisotropy. Calcite is one of many
black to white (the most common), and minerals that exhibit different values of
colorless clear or transparent. It can be almost physical and chemical properties on different
any other color of the spectrum. Calcite is also crystal sides or optical directions in its
easily dyed with proprietary dyes and crystalline shape. These variable properties,
techniques. Many are organic compounds that changes in numerical values in different

8 Calcite is rarely found in the unusual crystalline form geometry. Such noncleavage breaks are always very
of fibrous masses. Because the individual fiber-like irregular and rough. Fracture and cleavage may be
bundles of crystals are so small, it is easily carved and microscopic in scale.
has been mistakenly called alabaster, though it is not 10 Named after Iceland, where it is found in abundance.

the true gypsum-based material. Some specialized 19th century microscopes utilized the
9 In addition to cleavage, any mineral can be fractured optical characteristics of Iceland Spar and incorporated
other than along known planes of weakness in atomic a pair of precisely cleaved parallelogram-shaped calcite
crystals. Such instruments are now obsolete.

 2016 Marble Institute of America Marble and Onyx • Page 7-11

crystallographic directions, are known as elastic rebound that would normally occur
anisotropic properties. The differences, with hysteresis.
although very slight numerically, add up from
thousands to hundreds of thousands of 1.1.15.1 Events that can occur in calcite
crystalline mineral grains, to significant totals crystals in marble because of anisotropy and
that profoundly affect stone performance when thermal hysteresis include:
dealing with polished slabs of fine-grained
crystalline calcite. These slight, but important 1.1.15.1.1 Measurable extension on a
differences and behavioral characteristics must surface due to repeated, cyclic heating from the
be dealt with in the engineering design of sun or some other heat source.
marble installations. The anisotropic
properties of calcite that most seriously affect 1.1.15.1.2 Differential linear increases
marble performance are: across the front of thin panels vs. the back sides
can yield bowing, pillowing, or dishing of the
1.1.14.7.1 Solubility. Slight differences of sheet if too thin.
solubility on one or more of the three calcite
cleavages in the crystalline parallelogram- 1.1.15.1.3 Changes of intracrystalline
shaped crystals. The differential number may pressures, either increased or decreased, from
be very small, but the cumulative effect can be distorted shape, induces growth of calcite
a serious problem in an installation. crystals or dissolution of calcite (on different
crystal surfaces). Both chemical effects tend to
1.1.14.7.2 Ease of Cleavage. The ease of reduce strength and induce failure.
cleaving may be minutely different for each of
the three cleavages of a cleavage fragment, thus 1.1.15.1.4 Strained or distorted crystals
allowing preferential slippage to occur. accumulate from repeated heating cycles and
Although slight, in total it allows visible and become permanent.
permanent dislocations to accumulate,
ultimately leading to failure in some thinner 1.1.15.1.5 Microfractures develop from
sheets of marble. expansion or distortion of crystals and slippage
on cleavage.
1.1.14.7.3 Thermal Expansion and
Contraction. Varies with the various faces 1.1.15.1.6 Microfractures allow entrance of
and optical direction in crystals. For example, moisture and/or acid rain, which enlarges
calcite thermal expansion occurs in one fractures by solution, and in some cases,
crystallographic direction, while thermal loosely re-cements some areas and may at the
contraction occurs in crystallographic same time initiate formation of gypsum and
directions normal to the direction of granulation inside the stone and on the surface.
expansion. Both effects weaken stone, particularly on the
backside of bowed or pillowed sheets when
1.1.15 Thermal Hysteresis. Thin sheets moisture is present.
of certain marbles can sometimes fail under the
combined effects of the aforementioned 1.1.15.1.7 Reduction in strength of marble
anisotropic properties. Engineering practice sheets from the above microfractures and
recognizes the collective phenomena as thermal growth of softer, in-filling minerals.
hysteresis. Hysteresis is defined as “a lag in the
return of an elastically deformed body to its 1.1.15.1.8 Permanent distortion of shape:
original shape after the load has been removed. bowing, pillowing, and dishing, ultimately
One of the effects of anisotropy and repeated causing fractures and catastrophic failure.
thermal cycles is to defer and/or arrest the

Page 7-12 • Marble and Onyx  2016 Marble Institute of America

1.1.15.1.9 Reduced aesthetic appearance. 1.2.1 Although onyx is occasionally called
travertine, commercial practice generally
1.1.15.2 Such events do not occur in all distinguishes the two stones because of obvious
marbles. Anisotropic/hysteretic effects are differences that relate to their respective
most pronounced in the finer-grained, highly attractiveness. Onyx tends to be more
compacted, truly metamorphic marbles. crystalline, strongly banded and colored in
Anisotropic- and thermal-hysteretic problems browns to yellows and clear. It can be
generally are not seen with marbles of large translucent, and light-colored varieties sliced
grain or crystal size, nor are they seen where thin are used for attractive backlit display
the slabs are thick enough to counteract the panels or even light-admitting windows. By
forces and negate thermal differential between contrast, travertine displays large void spaces
front and back sides of the stone when effective and abundant, visible porosity, and is in all
moisture control is practiced for back sides. cases an opaque stone. Onyx, like most
limestone, will recrystallize in time (not a
1.1.15.3 Problems with marble arising from metamorphic process), often enhancing
anisotropy and thermal hysteresis can be translucency. It is the material that cameos are
avoided by intelligent stone selection, careful made from, and cameo makers use the stone’s
design, and engineering practices that colored bands to achieve artistic effects. Italy
recognize known chemical and physical produces much onyx, and the cameos carved in
properties and the effects of the variable Tuscany from highly-colored, banded onyx are
properties in calcite. world-renowned.

1.1.15.4 An excellent and complete

discussion of thermal hysteresis including 2.0 COLOR AND VEINING
actual test data and thickness recommendations
has been written by Bernard Erlin11 and 2.1 The color, veinings, clouds, mottlings,
published by ASTM International. and shadings in marble are caused by substances
included in minor amounts during formation.
1.2 Onyx originates in the dripstone Iron oxides make the pinks, yellows, browns,
deposits of limestone caverns, where it forms and reds. Most grays, blue grays, and blacks are
stalactites, stalagmites, and other formations of bituminous origin. Greens are caused by
that can fill an entire cavern or void space. It is micas, chlorites, and silicates.
deposited by gentle, dripping water movement
followed by evaporation between drops that
deposits calcium carbonate from the water 3.0 TEXTURE
onto the formation, incrementally enlarging
formations by thousandths of an inch or less per 3.1 The term “texture,” as applied to
drop. Thus onyx is also a chemical sedimentary marble, means size, degree of uniformity, and
stone, and may envelop terrestrial fossil arrangement of constituent minerals. Grains of
remains. Prehistoric human remains have been calcite, the chief constituent of most marbles,
found encased in cavern onyx. Although this are crystalline and have definite cleavage that
process of drop-by-drop addition of material show bright, reflecting faces on a broken
does take time, large deposits of onyx begin to surface. In most marbles, however, the grains
mature (filling caverns or fractures) in a are elongated in one direction by the folding
relatively short period of geologic time. and placation of the beds.

11Erlin, Bernard, “Contribution to a Better Construction, Evaluation, and Repair, ASTM STP 1394,
Understanding of the Mechanism Causing Dishing ASTM International, 2000.
Failures of the Carrara Marble When Used for Outside
on Building Facades.” Dimension Stone Cladding:

 2016 Marble Institute of America Marble and Onyx • Page 7-13

4.0 FINISHES 6.2 Selection and delivery can be greatly
facilitated by a jointing scheme that permits the
4.1 Marble’s surface may be finished in a use of smaller sizes. A final jointing scheme
number of ways. In general, smooth finishes should be agreed upon after the marble has
tend to emphasize color and veining, whereas been selected and the Marble Contractor has
rough finishes tend to subdue the veining or been consulted.
markings.
7.0 PRODUCT SAMPLING
4.2 Typical finishes for marble are:
7.1 Marble is formed by nature; thus, there
4.2.1 Polished: A glossy surface that brings are variations in the tonal qualities of the
out the full color and character of the marble. stones. However, it is these natural variations
It is not generally recommended for exterior that make marbles unique, valuable, and highly
use or commercial floors. desirable. Because of these variations, selection
of marble should never be made on the basis of
4.2.2 Honed: A satin-smooth surface with one sample only. It is recommended that
little or no gloss, recommended for selection be based on viewing sufficient
commercial floors. samples to show the complete range of colors
of the desired stone.
4.2.3 Abrasive: A flat, nonreflective surface,
usually recommended for exterior use. 8.0 PROPER USAGE TIPS
4.2.4 Other finishes, such as axed, bush 8.1 Recommendation for commercial
hammered, rock faced, rough sawn, or floors:
tooled, are also available.
8.1.1 Minimum ¾" thickness.
5.0 THICKNESS
8.1.2 A honed finish.
5.1 Standard nominal thicknesses for marble
veneer are ¾", 7/8", 1¼", 1½", and 2". 8.1.3 A minimum hardness value of 10 as
When a marble thinner than ¾" is specified, measured by ASTM C241.
the ratio between thickness and overall size and
the use of reinforcing backup materials must be 8.2 Avoid the use of gypsum or molding
considered. Marble thicker than 2" is usually plaster setting spots for the installation of
regarded as cubic stock. stone.

6.0 SIZES 8.3 Avoid using Soundness Classification C

and D marbles in wet areas, saunas, and steam
6.1 Marble is a product of nature with rooms.
hundreds of varieties available, each possessing
distinct characteristics. Little can be done to 8.4 Certain green colored marbles may
alter the condition in which nature presents warp when installed with water based
these varieties to us. Therefore, size may adhesives. Ask the Supplier for instructions.
become a limiting factor to consider in the
selection of marble. Check with the Stone 9.0 VENEER CUTTING
Supplier as to the sizes that are available for the
specific marble. 9.1 Quarry blocks are reduced to slabs by
a gang saw. The gang saw consists of a series of
steel blades set parallel in a frame that moves

Page 7-14 • Marble and Onyx  2016 Marble Institute of America

forward and backward. The most productive 10.4 Classification of marble is done by MIA
and precision gang saws have diamond-tipped Member producers. A written warranty should
blades with individual hydraulic blade be obtained from them prior to installation.
tensioners.
10.5 The four groups of Marble
9.2 Marble blocks can be sawn either Soundness Classification are:
parallel or perpendicular to the bedding plane.
The perpendicular cut is referred to as an 10.5.1 Group A marbles
across-the-bed or vein cut. The parallel cut is Sound marbles with uniform and favorable
with-the-bed or fleuri cut. Some marbles working qualities containing no geological
produce a pleasing surface when sawed in flaws or voids. They include completely
either direction, and are available as either vein metamorphosed limestone or dolostone, in
or fleuri. Other marbles produce a pleasing which impurities such as clays and silt have
surface only when sawed in one direction, and reacted chemically with the calcite or dolomite
are generally available only in that variety. to form other minerals. These stones have
uniform working qualities, can be used on the
exterior or interior, and do not require any
10.0 SOUNDNESS filling or patching.
CLASSIFICATION
10.5.2 Group B marbles
10.1 As a result of knowledge gained from Marbles similar in character to Group A,
extensive practical experience in the dimension except that all the impurities have not changed
stone industry, marbles have been classified into other minerals. Occasional small holes and
into four groups known as the Marble voids are to be expected, and are
Soundness Classification. characteristics of this group of marbles. The
holes or voids are filled by the Marble
10.2 The groupings–A, B, C, and D–should Craftsman with epoxy, shellac, or polyester
be taken into account when specifying marble, resin. (The terms “waxing,”12 “sticking,”13 and
for all marbles are not suitable for all building “filling” are common industry terms.) Filling is
applications. This is particularly true of the not intended to be noticeable to a great degree,
comparatively fragile marbles classified under perfectly color matched, or “glass” smooth.
Groups C and D, which may require additional May be used on the exterior or interior.
fabrication before or during installation.
10.5.3 Group C marbles
10.3 The basis of this classification is the Marbles with some variations in working
characteristics encountered in fabricating and qualities. Geological flaws, voids, veins, and
has no reference whatsoever to the lines of separation are common. Many of the
comparative merits or value of each type of impurities have not changed into other
marble. The classification indicates what minerals, and metamorphosis is not complete.
method of fabrication is considered necessary This is the largest and most colorful group of
and acceptable in each instance as based on marbles, and also contains significant holes,
standard trade practice, and applies only to voids, lines of separation, and structural flaws.
marble. It is standard practice to repair these variations

12Waxing refers to the practice of filling minor surface 13 Sticking describes the butt edge repair of a broken
imperfections such as voids or sand holes with melted piece, now generally done with dowels, cements, or
shellac, cabinetmaker’s wax or certain polyester epoxies. The pieces are “stuck” together; thus “sticking.”
compounds. It does not refer to the application of paste
wax to make surfaces shinier.

 2016 Marble Institute of America Marble and Onyx • Page 7-15

by use of reinforcing, liners, sticking together, generally more efficient buildings with more
filling with resin or cement, fabricating corners usable space, today’s Architects and Engineers
or missing stone with terrazzo and resin, and must get the most out of the materials with
doing all other work necessary to hold the which they work.
stone together to yield a finished product that
is usable for architectural purposes. On 1.3 Marble is a product of nature and not
completion, most repairs are visible and always subject to the rules of consistent
apparent, with a difference in light reflection. behavior that may apply to manufactured
With few exceptions, these marbles are not building materials. It may not be proper for
suitable for exterior installation. certain applications.

10.5.4 Group D marbles 1.4 Physical property values of marble

Marbles similar to the preceding group, but may, however, be measured using the standard
containing a larger proportion of natural faults, test methods approved by the Dimension Stone
maximum variations in working qualities, and Committee C18 of ASTM International. The
requiring more of the same methods of values found when stone is tested for
finishing. Few stones carry this designation at absorption, density, compressive strength,
this time; it is reserved for very laborious abrasion resistance, and flexural strength
Group C stones. should be useful for the Designer and Engineer
when preliminary construction calculations are
10.6 The Marble Soundness Classifications being made. However, these tests should be
indicate what method and amount of repair and made before the project specifications are
fabrication are necessary prior to or during written, not after. Member companies of the
installation, as based on standard trade Marble Institute of America are represented on
practices. this committee and are active in its technical
work of establishing proper test methods and
specifications consistent with the latest
technology.
TECHNICAL DATA -
Marble 1.5 The data shown in the following
table is the result of testing sixteen domestic
1.0 PROPERTIES OF MARBLE marble varieties at the Illinois Institute of
DIMENSION STONE Technology Research Institute, as well as
historical data and information established and
1.1 In centuries past, relatively little provided by ASTM International. Final design
importance was attached to the ultimate should always be based on specific values for
physical capabilities of most building materials. the marble variety ultimately to be installed.
Rule of thumb was a common structural design These values may be obtained from the Marble
criterion. As a result, the widely used materials Supplier.
of the day, for the most part natural rather than
manmade, were seldom stressed to their
ultimate limits.

1.2 In present-day construction,

however, this is far from being true.
Performance requirements are daily becoming
more demanding. In striving for taller
structures, greater spans, firmer foundations,
thinner walls and floors, stronger frames, and

Page 7-16 • Marble and Onyx  2016 Marble Institute of America

1.6 Physical Properties of Marble* depends on several factors: the rift and cleavage
of the crystals, the degree of cohesion, the
Property Range of Values interlocking of the crystals, and the nature of
any cementing materials present.
Compressive Strength (C170)
lbs/in² .............................. 6,000-35,000
Recommended (min): 7,500 3.0 FIRE RESISTANCE

Flexural Strength (C880) 3.1 Marbles are not combustible, according

lbs/in² .................................. 600-4,900 to underwriters’ ratings, and so are considered
Recommended (min): 1,000 a fire-resistant material. Because of its thermal
conductivity, however, the heat transfer
Modulus of Elasticity** (in millions) through marble is fairly rapid. Marble is not
lbs/in² ..................................... 1.5-5.0 considered a highly rated thermal insulator.

Density, lb/ft3 (C97) ................. 140-185 3.2 Underwriters’ fire resistance ratings
Recommended (min): evaluate whether or not a material will burn,
162 (calcite), as well as how long it will keep surrounding
175 (dolomite) combustible materials from reaching
temperatures which will cause them to ignite.
Thermal Conductivity “k” Pilot plant tests at The Ohio State University
Btu/in/hr/ft2/ºF ................... 10.45-15.65 Pyrotechnics Laboratory indicate that a 10
minute rating could be expected from 7/8"-
Water Vapor Permeability thick marble.
Perm-inch............................ 0.324-4.460
3.3 The use of an insulating material with
Coefficient of Thermal marble substantially improves the fire rating, as
Expansion in/in/ºF…. 3.7 x 10-6 – 5.0 x 10-6 shown below.

Modulus of Rupture (C99) 7/8" marble with 1" core of:

lbs/in² …. ........................... 1,000-4,000 Paper Honeycomb…………….…..½ hour
Recommended (min): 1,000 Cement-Bonded Wood Excelsior…...1 hour
Autoclaved Cellular Concrete…….1½ hour
Absorption, by weight % (C97) .....0.060-1.0
Recommended (max): 0.20 3.4 Methods of estimating fire resistance
periods of masonry walls and partitions
Abrasion Resistance Ha (C241)……5.0-50.0 utilizing component laminae are given in “Fire
Recommended (min): 10 Resistance Classifications of Building
Construction,” BMS92, National Bureau of
Standards.
* Test methods described in current ASTM
standards.
4.0 ABRASION RESISTANCE
** Also known as Young’s Modulus.
(ASTM C241)
4.1 Abrasion resistance is a property of
2.0 STRENGTH (ASTM C170, stone that should be tested per ASTM C241 to
ASTM C880) provide an indication of the stone’s wearing
qualities when exposed to foot traffic.
2.1 The strength of a marble is the measure
of its ability to resist stresses. This strength

 2016 Marble Institute of America Marble and Onyx • Page 7-17

4.2 The hardness and uniform wearing use of the material, and the less the cost of the
qualities of most marble varieties make them construction.
extremely desirable and economically practical 6.3 Contemporary design of buildings,
for floors and stairs. Varieties with an ASTM exclusive of the monumental type, does not
C241 abrasive hardness rating (Ha) of 10 or usually employ marble as part of the structural
more are recommended for use as flooring. A frame, but rather as an independent unit, a
minimum abrasive hardness of 12.0 is curtain wall, or veneer. Therefore, the
recommended for commercial floors, stair primary concern in such cases is with wind
treads, and platforms subject to heavy foot load, and a safety factor of 5.0 is
traffic. Surfaces of floors constructed with two recommended. Where the marble is to be
or more varieties, with Ha differences more subjected to concentrated loading, such as stair
than 5, will not wear evenly and uniformly. treads or lintels supported only at the ends, a
factor of 10.0 should be used.

5.0 FACTORS AFFECTING As buildings become taller and individual stone

PROPERTIES slab veneer becomes larger in area, the lateral
forces due to wind loads must be considered.
5.1 The ultimate test of a building material Wind tunnel tests are often used on major
is its ability to have and maintain the necessary structures to determine wind dynamics and
structural strength, as well as beauty of force magnitude. Reinforcement is sometimes
appearance and low cost of maintenance over necessary for large-dimension slab veneer in
the useful life of the structure. Experience has critical areas.
proven that marble meets this test as few other
building materials can.
7.0 SEISMIC CONSIDERATIONS
5.2 Illinois Institute of Technology Research
Institute’s studies have shown that the 7.1 Seismic considerations generally require
durability of marble is little affected by cycles that low buildings be stiff, and that tall
of weather. This is because of marble’s low rate buildings be relatively flexible. Design of
of moisture absorption. The rates of absorption connections must account for seismically
of all the marbles studied were less than 1 induced horizontal loading. Local building
percent by weight. Other masonry materials codes vary and must always be checked to
range upward from 4% to 12%. determine specific requirements for each area.

7.2 Additional Readings:

6.0 SAFETY FACTORS The National Bureau of Standards has published
two documents on the topic: “Earthquake
6.1 Good engineering practice requires that Resistant Masonry Construction,” NBS Science
allowable design stress must provide a margin Series 106; and “Abnormal Loading on
of safety in any structural element. As a Buildings and Progressive Collapse: An
necessary precaution against such conditions as Annotated Bibliography,” NBS Science Series
wind, ice, snow, impact, temperature changes, 67.
and imperfect workmanship, these allowable The U.S. Army Corps of Engineers also
stresses must be smaller than those which published TM 5-809-10, “Seismic Design for
produce failure. Buildings.”

6.2 Within the accepted limits of safe design

practice, the closer the allowable load is to the
ultimate failure load, the more efficient is the

Page 7-18 • Marble and Onyx  2016 Marble Institute of America

8.0 EFFLORESCENCE AND during or soon after erection. However, if left
STAINING alone, the stain is removed naturally by the
action of the elements, usually in the course of
8.1 Efflorescence is a salt deposit, usually a few months.
white in color that appears on exterior surfaces
of masonry walls. The efflorescence producing 8.6 A considerable amount of water passing
salts found in masonry are usually sulfates of through the stone is necessary to bring out
sodium, potassium, magnesium, calcium, and conspicuous discolorations. Proper
iron. Salts which are chlorides of sodium, precautions taken during construction of the
calcium, and potassium will sometimes appear, walls will usually prevent such troubles. A
but they are so highly soluble in water that they simple and helpful expedient is to provide
will be washed off by rain. frequent weep holes in the base course and
above shelf angles. These should be placed in
8.2 The water-soluble salts causing the vertical joints so they can be sloped upward
efflorescence come from other materials in the from the front to back.
wall. The salts exist in small amounts and are
leached to the surface by water percolating 8.7 Stains sometimes appear on the base
through the walls. The most feasible means of course when marble is in contact with soil, or
prevention is to stop the entrance of large on interior and exterior horizontal surfaces,
amounts of water. Absorption from the face due to the carrying of soluble salts and some
will not cause efflorescence unless there are colored soil constituents up through and to the
open joints. surface of the stone by capillary action. Almost
all soils and most of the veining in marble
8.3 Marble is not injured by efflorescence. contain soluble salts. Therefore, this staining
However, some of the salt crystals may form in phenomenon is similar to the discoloration
the pores near the surface. Crystal growth described previously, and will disappear when
(recrystallization) in the pores can put stress on the source of moisture is eliminated. However,
the walls of the pores and cause the stone to materials from the veining may remain on the
flake off. If the conditions bringing about this stone’s surface. In walls, provide venting so
action persist, scaling may continue and flake that moisture can escape through the venting
off one layer after another. For this to happen, rather than through the stone. On horizontal
large amounts of water must enter the wall and surfaces, the use of a vapor barrier between the
must contain large amounts of salts. setting bed and the concrete slab, or between
the setting bed and the ground, is
8.4 Research indicates that staining or recommended.
discoloration occurring on new buildings is
caused by the action of water percolating
through concrete from which soluble alkali 9.0 HYSTERESIS
salts are leached. The salts are then carried
through the marble, where partially oxidized 9.1 Hysteresis is a phenomenon that affects
organic matter is picked up. This is then certain “true” marbles. Unlike most stones,
transported to the surface of the stone, where which return to their original volumes after
it is deposited as a stain as evaporation of the exposure to higher or lower temperature,
water takes place. these marbles show small increases in volume
after each rise in temperature above the
8.5 This staining phenomenon is similar to starting point. This can result in differential
efflorescence except that it involves organic expansion within the stone, which is more
material. It does not harm the marble other likely to be accommodated or restrained in
than leaving an objectionable appearance thick veneers than in thin ones.

 2016 Marble Institute of America Marble and Onyx • Page 7-19

9.2 If it is not restrained, bowing of the 11.2.1 Crystal Structure: Marbles of
marble panels ensues and produces certain crystal structure are especially
compressive forces in the backs of panels. This adaptable to transmitting light.
causes creep, which in turn leads to permanent
deformation. “Dishing” also stretches the 11.2.2 Color: The white and lighter-
marble’s face, which makes stones more colored marbles are generally more
porous and increases their vulnerability to translucent.
corrosion from acids in the atmosphere and 11.2.3 Thickness: The light transmission
deterioration from freezing and thawing diminishes as panel thickness increases.
effects. If marbles with this tendency are
selected, it is important to determine the 11.2.4 Surface Finish: Translucency is
minimum thickness needed to overcome more apparent in smooth finishes than in rough
effects of hysteresis by testing under conditions finishes.
which simulate in place temperature gradients
of the wall.

10.0 THERMAL EXPANSION

10.1 The thermal expansion of marble is an

important consideration where marble is used
with dissimilar materials to form large units
which are rigidly fixed.
Laboratory tests for the coefficient of thermal
expansion of marble indicate that after several
cycles of heating and cooling, a residual
expansion of about 0.20% of the original
increase can be expected. This should be taken
into account when computing clearances. The
coefficient of thermal expansion varies from
one variety to another, so the actual thermal
characteristics of a specific marble should be
obtained from the quarries or fabricator before
making a final selection.

11.0 TRANSLUCENCE
11.1 The translucency of marble is one of
its most intriguing attributes. Not all marbles
possess this translucent quality, nor is the
degree of translucence the same in all varieties
that transmit some light.

11.2 Translucence is dependent, to a

greater or lesser extent, on the following
factors:

Page 7-20 • Marble and Onyx  2016 Marble Institute of America

NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

QUARTZ-BASED STONE 1.2.3.1 Membership, Products, and Services
Directory
1.0 GENERAL 1.2.3.2 Dimension Stone Design Manual
For purposes of this manual, Quartz-based 1.2.3.3 Additional publications may be
stone refers to sandstone, quartzitic sandstone, available from the MIA Bookstore. Go online
and quartzite. at www.marble-institute.com.
1.1 Related Documents 1.3 Scope of Included Work
1.1.1 Drawings and general provisions, 1.3.1 The work to be completed under this
including General and Supplementary contract includes all labor and materials
Conditions of the Contract and Division I required for the furnishing and installation of
Specification sections, apply to this section. all Quartz-based stonework shown or called
for on the contract drawings, specifications,
1.2 Applicable Publications and addenda.
1.2.1 The following publications listed here 1.4 Definition of Terms
and referred to thereafter by alphanumeric
code designation only, form a part of this 1.4.1 The definition of trade terms used in this
specification to the extent indicated by the specification shall be those published by the
references thereto: MIA or ASTM International.
1.2.2 ASTM International (ASTM):
1.5 Source of Supply
1.2.2.1 C616, Standard Specification for
Quartz-based Dimension Stone 1.5.1 All Quartz-based stone shall be obtained
from quarries having adequate capacity and
1.2.2.2 C97, Standard Test Methods for facilities to meet the specified requirements
Absorption and Bulk Specific Gravity of and by a firm equipped to process the material
Dimension Stone promptly on order and in strict accord with
specifications. The Specifying Authority
1.2.2.3 C99, Standard Test Method for (architect, designer, engineer, contracting
Modulus of Rupture of Dimension Stone officer, end user, etc.) reserves the right to
approve the Material Supplier prior to the
1.2.2.4 C170, Standard Test Method for award of this contract. Stone and workmanship
Compressive Strength of Dimension Stone quality shall be in accordance with Industry
Standards and Practices as set forth by the MIA.
1.2.2.5 C241, Standard Test Method for
Abrasion Resistance of Stone Subjected to Foot 1.6 Samples
Traffic
1.6.1 The Quartz-based Stone Supplier shall
1.2.2.6 C880, Standard Test Method for submit through the General Contractor, for
Flexural Strength of Dimension Stone approval by the Specifying Authority, at least
two sets of samples of the various kinds of
1.2.3 Marble Institute of America Quartz-based stone specified. The sample size
(MIA): shall be 1'-0" x 1'-0" and shall represent
approximately the finish, texture, and
anticipated range of color to be supplied. One

 2016 Marble Institute of America Quartz-Based Stone • Page 8-1

set of samples shall be retained by the or other design loads; (2) engineering
Specifying Authority, and one set shall be estimates; (3) plans or specifications; or (4) the
returned to the Quartz-based Supplier for types, sizes, or locations of anchors, unless
project record and guidance. It is noted herein specifically added to the scope of work.
that Quartz-based stone is a natural material
and will have variations in color, markings, and 1.8 Defective Work
other characteristics. Stone is a product of
nature. It is not possible to guarantee that all 1.8.1 Any piece of Quartz-based stone
the colors and markings of a large stone deposit showing flaws or imperfections upon receipt at
will be present in every piece and that every the storage yard or building site shall be
characteristic will be uniformly present in referred to the Specifying Authority for
other pieces. Depending on Quartz-based determination as to responsibility and decision
stone selected and quantity required, a range as to whether it shall be rejected, patched, or
mockup may be required to further define the redressed for use.
characteristics of the material. When required,
the cost of the mockup shall be included in this 1.9 Repairing Damaged Stone
section.
1.9.1 Chips at the edges or corners may be
1.6.2 Prior to fabrication, an inspection and patched provided the structural integrity of the
approval by the Specifying Authority (and/or stone is not affected and provided the patch
General Contractor and/or End User) of a matches the color and finish of the natural
representative number of the finished slabs stone so that it does not detract from the
may be desirable to understand the finish and stone’s appearance.
full range of the material

1.7 Shop Drawings 2.0 MATERIALS

1.7.1 The Quartz-based Stone Supplier shall
2.1 Quartz-based Stone
submit through the General Contractor, for
approval by the Specifying Authority, sufficient
2.1.1 General: All Quartz-based stone shall
sets of shop drawings showing general layout,
be of architectural standard grade, free of
jointing, anchoring, stock thickness, and such
cracks, seams, starts, or other traits which may
other pertinent information. These drawings
impair its structural integrity or function.
shall show all bedding, bonding, jointing, and
Inherent color variations characteristic of the
anchoring details along with the net piece
quarry from which it is obtained will be
dimensions for each Quartz-based unit. Setting
acceptable. Texture and finish shall be as
numbers are to be shown, if applicable. One
shown in the sample(s) approved by the
copy of the approved shop drawings shall be
Specifying Authority.
retained by the Specifying Authority, one copy
shall be retained by the General Contractor,
2.1.2 ASTM C616 [C97] [C99] [C170]
and one copy returned to the Quartz-based
[C241] [C880] See the chart of applicable
Stone supplier for fabrication. NO
ASTM standards and tests in the Appendix.
FABRICATION OF QUARTZ-BASED
STONE SHALL BE STARTED UNTIL SUCH
2.1.3 Schedule: Quartz-based stone shall
DRAWINGS HAVE BEEN FULLY
be provided as follows:
APPROVED AND MARKED AS SUCH. The
Quartz-based Stone Supplier shall not be
2.1.3.1 For (state location on building) (state
responsible for determining, making, or
name and color) Quartz-based stone with a (type)
verifying (1) design, structural, wind, seismic,

Page 8-2 • Quartz-Based Stone  2016 Marble Institute of America

finish, supplied by (name company or list several 2.5 Anchors, Cramps, and
approved suppliers). Dowels
2.1.3.2 Provide information as in (1) for
each different Quartz-based stone/finish 2.5.1 All wire anchors, cramps, dowels, and
combination in the project. other anchoring devices shall be nonferrous
metal of the types and sizes shown on approved
2.1.4 Finishes: Available in cleft, chat shop drawings.
sawn, and diamond sawn, sand sawn, honed,
polished, rubbed, machine tooled, smooth
planed, split face, and rock face.
3.0 FABRICATION
2.1.5 Finishes listed in the schedule shall
conform with definitions by the MIA or ASTM 3.1 Beds and Joints
International.
3.1.1 Bed and head joint size shall be
determined by analysis of anticipated building
2.2 Setting Mortar
movements and designed to accommodate
such movements without inducing undue
2.2.1 Mortar for setting and pointing shall
stresses in the stone panels or joint filler
be one part portland cement and one part
materials. Expansion joints shall be designed
plastic lime hydrate to three to five parts of
and located to accommodate larger
clean, nonstaining sand. It shall be mixed in
movements.
small batches, using clean, nonalkaline water
with a pH of 7 until it is thoroughly
3.1.2 Some slight lippage and variation is
homogeneous, stiff, and plastic. After mixing,
natural and unavoidable where a rough finish
the mortar shall set for not less than one hour
face comes together at the sawed joints.
or more than two hours before being used.
3.1.3 Joints ¼", 3/8", or ½" are
2.3 Pointing Mortar recommended between standard-size panels.
All joints are to be water- and moisture-tight
2.3.1 Mortar for pointing shall be Type N, and caulked with a proper sealant.
as defined in ASTM C270 (Standard
Specification for Mortar for Unit Masonry).
3.2 Backs of Pieces
All mixing, handling, and pacing procedures
shall be in accordance with ASTM C270.
3.2.1 Backs of pieces shall be sawn or roughly
dressed to approximately true planes. Back
2.4 Sealants and Backup surfaces shall be free of any matter that may
Material (If Applicable) create staining.

2.4.1 Where specified, (state type or name of 3.3 Moldings, Washes, and Drips
sealant) shall be used for the pointing of joints.
The backup material used with the sealant shall 3.3.1 Moldings, washes, and drips shall be
be (identify material). Joint sealants are to constant in profile throughout their entire
comply with ASTM C920. Submit samples for length, in strict conformity with details shown
stain testing in accordance with ASTM D2203. on approved shop drawings. The finish quality
on these surfaces shall match the finish quality
of the flat surfaces on the building.

 2016 Marble Institute of America Quartz-Based Stone • Page 8-3

3.4 Back-checking and Fitting to responsibility of the Quartz-based Stone
Structure or Frame Contractor.

3.4.1 Stone coming in contact with structural 3.6.2 Incidental cutting such as for window
work shall be back-checked as indicated on the frame clips, etc., which is normally not
approved shop drawings. Stones resting on considered to be the responsibility of the Stone
structural work shall have beds shaped to fit the Supplier, will be provided only by arrangement
supports as required. by the General Contractor and Quartz-based
Stone Contractor with the Quartz-based Stone
3.4.2 Maintain a minimum of 1" between Fabricator.
stone backs and adjacent structure. (Note:
many bolted connections will require more
space than this; 2" space may be more 4.0 SHIPPING AND HANDLING
desirable. Large-scale details should illustrate
and control these conditions.) 4.1 Packing and Loading

3.5 Cutting for Anchoring, 4.1.1 Finished Quartz-based stone shall be

Supporting, and Lifting Devices carefully packed and loaded for shipment using
all reasonable and customary precautions
3.5.1 Holes and sinkages shall be cut in stones against damage in transit. No material which
for all anchors, cramps, dowels, and other may cause staining or discoloration shall be
tieback and support devices per industry used for blocking or packing.
standard practice or approved shop drawings.
However, additional anchor holes shall be 4.2 Site Storage
drilled at job site by Quartz-based Stone
Contractor to facilitate alignment. 4.2.1 Upon receipt at the building site, stone
shall remain in the factory-prepared bundles
3.5.2 No holes or sinkages will be provided until beginning of the installation. Bundles
for Quartz-based Stone Contractor's handling shall be staged in an area which is least
devices unless arrangement for this service is susceptible to damage from ongoing
made by the Quartz-based Stone Contractor construction activity. Once unbundled, the
with the Quartz-based Stone Fabricator. granite shall be stacked on timber or platforms
at least 2" above the ground, and the utmost
(NOTE: It is not recommended that lewis pins care shall be taken to prevent staining or
be used for stones less than 3½" thick). impact damage of the stone. If storage is to be
prolonged, polyethylene or other suitable,
3.6 Cutting and Drilling For nonstaining film shall be placed between any
wood and finished surfaces of the stone.
Other Trades
Polyethylene or other suitable, nonstaining
film may also be required as protective
3.6.1 Any miscellaneous cutting and drilling
covering.
of stone necessary to accommodate other
trades will be done by the Quartz-based Stone
Fabricator only when necessary information is
furnished in time to be shown on the shop
drawings and details, and when work can be
executed before fabrication. Cutting and
fitting, due to job site conditions, will be the

Page 8-4 • Quartz-Based Stone  2016 Marble Institute of America

5.0 INSTALLATION contact area shall be not less than 80%, except
on exterior or shower installations, where
5.1 General Installation contact shall be at least 95% when no less than
three tiles are removed for inspection.
5.1.1 Installation shall be accomplished with
competent, experienced Stone Setters, in 5.2.4 Veneer shall be set by spotting with
accordance with the approved shop drawings. gypsum molding plaster for interior use, or
cement mortar and the use of concealed
5.1.2 All Quartz-based stone pieces shall be anchors secured in the wall backing.
identified with a unique piece number
corresponding with the number on the shop 5.2.5 Where thin wall tile (nominal 5/8"
drawings. Interchanging of numbered pieces is thick) is used, nonstaining adhesives or dry-set
not permitted. mortars may be employed. Individually set thin
tile (nominal 3/8" thick) on vertical surfaces
5.1.3 Quartz-based stone shall be free of any exceeding 8' is not recommended.
ice or frost at time of installation. Salt shall not
be used for the purpose of melting ice, frost, or 5.2.6 Panels set in metal frames shall have
snow on the stone pieces. rabbeted edges and a sealant for all joints to
prevent moisture seepage. Hairpin spring
5.1.4 Adequate protection measures shall be anchors in the back of the panels make Quartz-
taken to ensure that exposed surfaces of the based stone easily adaptable as facings for
stone shall be kept free of mortar at all times. precast units and systems.

5.2 Mortar Setting 5.3 Mortar Joints

5.2.1 Unless otherwise shown on approved 5.3.1 Mortar joints shall be raked out to a
shop drawings, each piece shall be carefully laid depth of ½" to ¾". Apply pointing mortar in
in a full bed of mortar and tapped to a full and layers not exceeding 3/8" and allow each layer
solid bearing. Exposed surfaces shall be kept to get hard to the touch before the next layer is
free of mortar at all times. applied. Tool finished joints with a concave
tool having a diameter approximately 1/8"
5.2.2 If the thin-set method is used (for 5/8" greater than the joint width.
thick stone) a dry-set portland cement mortar
is applied with a 3/8" or ½" notched trowel 5.3.2 Care shall be taken to keep expansion
with back buttering of the clean, moist tile joints free of mortar, which would
surface. compromise their function.

5.2.3 Apply mortar with flat side of trowel 5.4 Anchorage

over an area that can be covered with tile while
mortar remains plastic. Within ten minutes 5.4.1 The stone shall be anchored or doweled
and using a notched trowel of type in accordance with the approved shop
recommended by Mortar Manufacturer, comb drawings.
mortar to obtain even-setting bed without
scraping backing material. Cover surface 5.4.2 To the furthest extent possible, all
uniformly, with no bare spots, with sufficient anchor preparations in the Quartz-based stone
mortar to ensure a minimum mortar thickness units shall be shop-applied.
of 3/32" between tile and backing after tile has
been tamped into place. Tile shall not be 5.4.3 All anchorage devices and anchor
applied to skinned-over mortar. Average hole/slot fillers shall be in accordance with

 2016 Marble Institute of America Quartz-Based Stone • Page 8-5

ASTM C1242. Care must be taken to ensure 6.0 CLEANING AND
that any holes capable of retaining water are PROTECTION
filled after use to prevent water collection and
freezing.
6.1 Cleaning
5.5 Sealant Joints
6.1.1 Upon completion of various portions of
work, all mortar stains, grease marks, and dirt
5.5.1 Where so specified, joints requiring
should be removed by washing with a good
sealant shall be first filled with a closed-cell
grade of nonabrasive detergent with a pH of 7.
ethafoam rope backer rod. The backer rod
Flush and clean with clear water. Floors can be
shall be installed to a depth that provides
swept, damp-mopped, or hosed off with clean
optimum sealant profile after tooling.
water.
5.5.2 If recommended by the Sealant
Manufacturer, primers shall be applied to the 6.2 Protection of Finished Work
substrate surfaces according to the
manufacturer’s directions prior to application 6.2.1 Quartz-based stone installation in
of the joint sealant. progress shall be protected with film, fabric
tarps, and wood for exposed edge protection
secured over the work.
5.6 Expansion Joints
6.2.2 After the Quartz-based stone has been
5.6.1 It is not the intent of this specification to installed, it shall be the responsibility of the
make control or expansion-joint General Contractor to see that it is properly
recommendations for a specific project. The and adequately protected from damage and
Specifying Authority must specify control or stains until all trades are finished. This
expansion joints and show locations and details responsibility includes the stone cleaning costs
on drawings. prior to the final inspection. The Quartz-based
Stone Contractor will outline the needs for
5.7 Caulking protection, in writing, to the General
Contractor.
5.7.1 Where so specified, joints shall be
pointed with the sealant(s) specified in Section
2.4 after first installing the specified backup
material and applying a primer if required, all PRODUCT
in strict accordance with the printed DESCRIPTION –
instructions of the sealant manufacturer. Quartz-based Stone
5.7.2 All sealants shall be tooled to ensure 1.0 GEOLOGICAL
maximum adhesion to the contact surfaces.
CLASSIFICATION
5.8 Weep Tubes 1.1 Most types of Quartz-based stones are
clastic sedimentary stone, composed of
5.8.1 Plastic or other weep tubes shall be particles or grains usually cemented with
placed in joints where moisture may varying amounts of either hydrous silica or
accumulate within the wall, such as at base of crystalline quartz. A notable exception is the
cavity, continuous angles, flashing, etc., or as chert group, including chert, agate, and flint,
shown on architectural drawings. which are siliceous chemical sedimentary
stones.

Page 8-6 • Quartz-Based Stone  2016 Marble Institute of America

1.2 The following are the main groups mountains, hills, and highlands, and across the
of Quartz-based stone: plains to lakes, seas, and into the oceans,
depositing the debris on beaches and beyond to
1.2.1 Quartz, Crystalline Quartz form into new sedimentary stone. During this
natural process, soluble salts are released from
1.2.2 Sandstone the debris, and some of these salts ultimately
run off into below-sea level lakes and into
1.2.3 Quartzite oceans as dissolved salts, giving the oceanic
water its briny content.
1.2.4 Metaquartzite
1.6 Crystalline quartz has a fixed chemical
1.2.5 Quartz Pebble Conglomerates composition: SiO2. Some other quartz types
occur as hydrous silica (SiO2•NaH2O), the
1.2.6 Metaconglomerates mineral of chert, agate, flint, and fire opal.
These stones are about H=6 to 6.5 on the
1.2.7 Chert, Agate, Flint Mohs Scale,2 not quite as hard as crystalline
quartz.
1.3 The key to understanding all Quartz-
based stone is the understanding of crystalline 1.7 Physical properties of crystalline
quartz as a mineral. The basic physical quartz:
properties of quartz – with the possible
exception of absorption and porosity – are the 1.7.1 Hardness. Quartz has a Mohs Scale
same as those of any Quartz-based stone. hardness rating of 7. It can scratch minerals
with a hardness of less than 7, such as calcite
1.4 Quartz (SiO2) is composed of the two and feldspar, but cannot scratch other quartz or
most abundant elements in the Earth’s crust: minerals with a hardness greater than 7, such as
silicon and oxygen, which respectively make corundum and diamond.
up 28% and 47% by weight of our planet’s
lithosphere. Of all the common minerals, 1.7.2 Shape. Quartz crystals are always six-
quartz lasts the longest in the environment. sided, elongate prisms with a pyramid-shaped
Most of the beaches in the world, with a few termination usually on one end of the prism
exceptions, are quartz sand.1 Almost all other only. The prisms may be imperfect, but the
minerals are abraded away, broken up angles between sides are always equal, even
mechanically through weathering and though the prismatic sides are very unequal in
transportation, or, if soluble, dissolved. width.
Quartz is itself slightly soluble, giving rise to
the chert deposits found in many sedimentary 1.7.3 Lack of Cleavage. Quartz does not
sequences. have “cleavage,” the weakness in molecular
geometry along which a mineral consistently
1.5 Weathering of igneous, sedimentary, break.
and metamorphic rocks releases grains of
quartz sand. Water, gravity, and wind 1.7.4 Fracturing. When quartz fractures, it
transport this rock debris (detritus) down can break with dish-shaped, irregular surfaces.

1 A few beaches are entirely carbonate sand created by small, red, single-cell marine organisms. In Hawaii,
waves breaking up seashells into coarse, sand-sized there are beaches of only black or green volcanic sand
grains. Some of these beaches have no land-derived with no quartz sand content.
silicate minerals or rock fragments. The beaches of 2 See Appendix for the Mohs Scale of mineral hardness.

Bermuda are a well-known example. There, the sands

are pink from coloration derived from the remains of

 2016 Marble Institute of America Quartz-Based Stone • Page 8-7

The dished surfaces often have small concentric 1.9 Quartzite, the silica-cemented,
ridges giving it a “conchoidal” surface effect, unmetamorphosed variety, tends to occur in
after sea-shells with similar shapes and sedimentary units or beds, and the thicker
concentric ridges. Fractured quartz faces are quartzite ledges are generally more useful than
rough, uneven, and never flat.3 the thinner occurrences. With thicker units of
quartzite, the distinction between
1.7.5 Coloring. Quartz occurs naturally in a metamorphosed and unmetamorphosed types
range of colors. Some colored quartz crystals makes little difference to those in the stone
are prized as semiprecious gems, e.g., citrine industry. Quartzite breaks across grains, not
(yellow), amethyst (lavender to purple), and around grains. Thus it is very hard (H=7),
jasper (yellow, brown, red), to name a few. durable, and for practical purposes, not a
This natural coloring is due to micro inclusions soluble stone, making it a desirable material for
or traces of other elements in the stone’s some difficult installations where exposure to
chemistry. However, not all quartz available water may be a problem.
on the market is naturally colored. Artificial
coloring processes are sometimes used in the 1.10 Metaquartzite. The metamorphic
gem industry to dye fractured crystalline equivalent of quartzite is metaquartzite. Often
quartz in colors not seen in nature, such as difficult to differentiate from its
bright pink and fluorescent shades of green, nonmetamorphosed parent stone,
yellow, and blue. metaquartzite has certain distinct features; for
example, thin “partings” of clear mica often
1.7.6 Electrical Properties. Quartz is separate layers or bands of pure metaquartzite.
“piezoelectric,” an unusual electrical property Some deposits of the stone occur in layers only
that has no effect on the performance of the 1/8" to ½" thick, separated by the micaceous
mineral in normal dimension stone parting that allows easy separation or cleaving
applications. If squeezed, quartz generates an characteristic of mica sheets, due to weak
electrical current proportional to the amount molecular bonds.
of pressure applied. When a small current is
generated on two opposing faces of a cut, 1.11 These mica partings should not be
ground quartz crystal, it vibrates electrically, confused with former bedding. The partings
acting as an oscillator at a frequency are a form of banding developed from the
determined by the exact thickness of the mineral segregation that occurs in the process
crystal. These were used in communications of metamorphism. Thin metaquartzite is
equipment from the 1920s to the 1950s to valued for use in flooring and decorative stone
control broadcast frequencies, but are now applications.
obsolete.
1.12 Quartz pebble conglomerates,
1.8 Sandstone is a nonmetamorphic unless silica-cemented, may tend to
sedimentary stone. When firmly cemented disaggregate rather easily, particularly if the
with silica, sandstone could be correctly quartz pebbles are highly rounded and smooth
identified as quartzite. However, it is and the cement is not strong, especially if the
suggested the name quartzite should be cementing agent and matrix is the soluble
restricted for sandstone tightly cemented with mineral calcite or limestone. If the
homogeneous crystalline silica (quartz conglomeratic matrix is silica, then the stone
crystals). will break through the quartz pebbles. A quartz
pebble conglomerate may occasionally consist

3 Crystalline Quartz can be deposited in a void against as a consequence of the atomic geometry of quartz.
an existing crystal face of another mineral. The The only true, flat quartz face is a crystal face.
resulting flat face on quartz is an artifact, not originating

Page 8-8 • Quartz-Based Stone  2016 Marble Institute of America

of a variety of colored quartz pebbles including 2.2 The purest Quartz-based stones are
white, yellows, reds, black, and sometimes nearly white. Colors are primarily due to iron
banded agate. A multicolored quartz pebble oxides. The presence of limonite usually yields
conglomerate with red siliceous cement is yellow, brown, and buff shades; the presence
found on the Iberian Peninsula and in the Atlas of hematite yields darker brown or red.
Mountains of North Africa. This type is a Oxidation of iron-bearing minerals upon
valuable dimension stone. exposure may cause some stones to change
color after installation.
1.13 Metaconglomerates. Metaquartz
pebble conglomerates, like metaquartzite, will 2.3 Since most Quartz-based stones are
break through and not around grains and formed in layers through centuries, each layer
pebbles. Other strongly metamorphosed may have considerable color variations. It is not
conglo-merates have been squeezed under such uncommon that some may have a color range
high pressure that the quartz pebbles are of possibly up to 12 shade variations. If a
flattened. The plane of flattening is normal minimal amount of shade variation is desired,
(perpendicular to the direction of pressure), then additional quarrying time will be
and flattened pebbles of hard quartz are a required, as well as special, hand-selection
notable example of how high the pressures of costs.
metamorphism can be.

1.14 Chert, Agate, Flint. These are varietal 3.0 TEXTURE

names for hydrous silica deposits that can occur
in beds or nodules. Chert, the preferred 3.1 The term “texture,” as applied to
geological name, is classified as chemical Quartz-based stone, means size, degree of
sedimentary stone. Cherts are true chemical uniformity, and arrangement of constituent
precipitates emplaced within a sedimentary minerals. Quartz-based stones are essentially
sequence at some time after burial and perhaps quartz; some are nearly pure quartz.
before cementation.
3.2 Grains of quartz may be well-rounded
1.15 Some cherts, like red jasper, are or angular, depending upon the degree to
valuable as semiprecious stones sold and used which they were water-worn before
by gemstone hobbyists. Banded or lace agate consolidation. Some deposits show remarkable
can be valuable for jewelry or as an exceedingly uniformity in size of grains. This grain
rare and expensive dimension stone. Entire composition can affect the texture.
fireplace mantles and part of the surround have
been made from large, exquisite sheets of 3.3 Texture of Quartz-based stone is also
agate. Because it is softer than crystalline affected by the way that the grains of silica
quartz, Agate was often the material used to fracture. Sandstone fractures around the
carve mortars and pestles for use in 19th constituent grains. Quartzitic sandstone
century pharmacies. It was also used to make fractures around or through the constituent
marbles for the game popular with 19th and grains. Quartzite fractures conchoidally
early 20th century children. through the grains.

2.0 COLOR AND VEINING 3.4 Quartz-based stones are the most
variable type of dimension stone due to wide
2.1 The color, veinings, clouds, mottlings, variety in degree of cementation and type of
and shadings in Quartz-based stone are caused cementing material between the grains. There
by substances included during formation. are four common cementing materials: iron
oxides, clay, calcite, and quartz. All stages of

 2016 Marble Institute of America Quartz-Based Stone • Page 8-9

cementation are found in nature, from may become a limiting factor to consider in the
incoherent sandstones that may be crumbled selection of a particular Quartz-based stone.
between the fingers, to the most hardened
quartzites. All types between these extremes 6.2 A jointing scheme which permits the use
are used commercially. of appropriate sizes of Quartz-based stone
yielded by the particular quarry will greatly
3.5 Sandstones may be relatively high facilitate selection and delivery.
porosity stones. Quartzites, on the other hand,
can have as little pore space as granites.
7.0 PRODUCT SAMPLING
4.0 FINISHES 7.1 Quartz-based stones are formed by
nature; thus, there are variations in the tonal
4.1 A common finish for Quartz-based stone qualities of the stones. However, it is these
is natural cleft finish. It should be noted that the natural variations that make Quartz-based
face of natural-cleft stone is not necessarily a stone unique, valuable, and highly desirable.
true flat surface. This surface may vary from Because of these variations, selection of a stone
flat to variations up to ¼" from true flat. This should never be made on the basis of one
could result in a surface that is concave or sample only. It is recommended that selection
convex, or could also be warped or be based on viewing sufficient samples to show
“propellered” (corners tipping either down or the complete range of color of the desired
up). stone. (See “2.0 Color and Veining” in this
chapter section for additional information.)
4.2 Many of the standard finishes can be
applied to Quartz-based stones.
8.0 PROPER USAGE TIPS
4.3 Some stone finishes can affect strength
and durability. Examples are bush-hammered 8.1 Recommendation for commercial
and thermal finishes, which reduce a stone’s floors:
thickness, making it more vulnerable to
weakening from exposure to freeze and thaw 8.1.1 Minimum ¾" thickness.
cycles.
8.1.2 A honed finish.
5.0 THICKNESS
8.1.3 A minimum hardness value of 2
5.1 As these are split stones, standard (Sandstone), 8 (Quartzitic Sandstone), and 8
thicknesses are highly variable, e.g., ¾", 1½", (Quartzite) as measured by ASTM C241.
2", 4", or 8".
8.2 Avoid the use of gypsum or molding
Note: As Quartz-based stone is cut thinner, its plaster setting spots for the installation of
tensile strength is diminished. exterior stone.

6.0 SIZES 9.0 TOLERANCES

6.1 Quartz-based stone is a product of 9.1 Because of the many variances in

nature with many varieties available, each cementation and porosity, it is recommended
possessing varying characteristics. Little can be that the Quartz-based Stone Quarrier or
done to alter the condition in which nature Fabricator be contacted regarding size and
presents these varieties to us. Therefore, size thickness tolerances.

Page 8-10 • Quartz-Based Stone  2016 Marble Institute of America

10.0 FABRICATION 1.4 Final design should always be based on
specific values for the stone variety ultimately
10.1 One process after quarrying Quartz- to be installed. These values may be obtained
based stone is to guillotine the slabs to the from the Stone Supplier. All materials are not
desired length and thickness, thus the thick suitable for all uses. In order to avoid mistaken
slabs can be split to the desired thicknesses of selections, tests for material values should be
2", 3", or 4". made prior to final material selection.

1.5 Physical Properties of Quartz-

based Stone
TECHNICAL DATA – (These historical data and information are
Quartz-based Stone provided only as a guideline. Recommended
minimums or maximums are established and
1.0 PROPERTIES OF QUARTZ- provided by ASTM International.)*
BASED DIMENSION STONE Property Range of Values
1.1 In centuries past, relatively little Compressive Strength (C170)
importance was attached to the ultimate lbs/in² .............................. 2,000-37,000
physical capabilities of most building materials. Recommended (min):
Rule of thumb was a common structural design 4,000 (sandstone),
criterion. As a result, the widely used materials 10,000 (quartzitic sandstone),
of the day, for the most part natural rather than 20,000 (quartzite)
man-made materials, were seldom stressed to Flexural Strength (C880)
their ultimate limits. lbs/in² ...................................700-2,300
1.2 In present-day construction, this is far Modulus of Elasticity** (in millions)
from being true. Performance requirements lbs/in² ..................................... 1.0-1.75
are daily become more demanding. In striving Density, lb/ft3 (C97) .................. 135-170
for taller structures, greater spans, firmer Recommended (min):
foundations, thinner walls and floors, stronger 125 (sandstone),
frames, and generally more efficient buildings 150 (quartzitic sandstone),
with more usable space, today’s Architects and 160 (quartzite)
Engineers must get the most out of the
materials with which they work. Modulus of Rupture (C99) lbs/in².300-2,500
Recommended (min):
1.3 Quartz-based stone is a product of 350 (sandstone),
nature and not always subject to the rules of 1,000 (quartzitic sandstone),
consistent behavior that may apply to 2,000 (quartzite)
manufactured building materials. Physical Absorption (by weight) % (C97) …..1.0-20.0
property values of Quartz-based stone may, Recommended (max):
however, be measured using the standard test 8.0 (sandstone),
methods approved by the Dimension Stone 3.0 (quartzitic sandstone),
Committee C-18 of ASTM International. The 1.0 (quartzite)
MIA and Member companies are represented
on the ASTM committee and are active in its * Test methods described in current ASTM
technical work of establishing proper test standards.
methods and specifications consistent with the ** Also known as Young’s Modulus.
latest technology.

 2016 Marble Institute of America Quartz-Based Stone • Page 8-11

2.0 STRENGTH (ASTM C99, 4.0 ABRASION RESISTANCE
C170, C880) (ASTM C241)

2.1 Values for modulus of rupture, 4.1 Abrasion resistance is a property of

compressive strength, and flexural strength are stone that should be tested per ASTM C241 to
ascertained by testing specimens of Quartz- provide an indication of the stone’s wearing
based stone under laboratory conditions until qualities when exposed to foot traffic.
they fail.
4.2 The hardness and uniform wearing
2.2 Size and finish of test samples required qualities of most Quartz-based stones make
by the standard ASTM test methods may not them extremely desirable and economically
reflect the actual performance of stone when practical for floors and stairs. Varieties with an
used in lesser thicknesses or with other finishes abrasive hardness (Ha) of 8 or more, as
that affect strength. For this reason, the measured by ASTM C241 tests, are
Modulus of Rupture (C99) test is recommended for use as flooring exposed to
recommended when the stone to be used will normal foot traffic. A minimum abrasive
be two or more inches thick. The Flexural hardness of 12 is recommended for
Strength (C880) test is recommended when commercial floors, stair treads, and platforms
the stone thickness will be less than two inches. subject to heavy foot traffic. If floors are
constructed with two or more stone varieties,
2.3 The strength of a Quartz-based stone is the Ha values of the stones must not differ by
a measure of its ability to resist stresses. This more than 5, or the floor surface will not wear
strength depends on several factors: the evenly and uniformly.
amount of free silica, degree of cementation,
porosity, and whether the stone is
metamorphosed. 5.0 FACTORS AFFECTING
PROPERTIES
3.0 FIRE RESISTANCE 5.1 The ultimate test of a building material
is its ability to have and maintain the necessary
3.1 Stone is not combustible according to structural strength, as well as beauty of
underwriters’ ratings, and therefore is appearance and low cost of maintenance, over
considered a fire-resistant material. Because of the useful life of the structure. Experience has
its thermal conductivity, heat transfer is fairly proven that stone meets this test as few other
rapid. Most stone is not considered a highly building materials can. Studies have shown that
rated thermal insulator. the durability of most stones is little affected by
cycles of weather. This is because most have a
3.2 Underwriters’ fire-resistance ratings low rate of moisture absorption.
evaluate whether or not a material will burn,
as well as how long it will keep surrounding
combustible materials from reaching 6.0 SAFETY FACTORS
temperatures which will cause them to ignite.
Methods of estimating fire-resistance periods 6.1 Good engineering practice requires that
of masonry walls and partitions utilizing allowable design stress must provide a margin
component laminae are given in “Fire of safety in any structural element. As a
Resistance Classifications of Building necessary precaution against such conditions as
Construction,” BMS92, National Bureau of wind, ice, snow, impact, temperature changes,
Standards. and imperfect workmanship, these allowable

Page 8-12 • Quartz-Based Stone  2016 Marble Institute of America

stresses must be smaller than those which 67. The U.S. Army Corps of Engineers has also
produce failure. published TM 5-809-10, “Seismic Design for
Buildings.”
6.2 Within the accepted limits of safe design
practice, the closer the allowable load is to the
ultimate failure load, the more efficient is the 8.0 EFFLORESCENCE AND
use of the material and the less the cost of the STAINING
construction.
8.1 Efflorescence is a salt deposit, usually
6.3 Contemporary building design does not white in color that appears on exterior surfaces
usually employ stone as part of the structural of masonry walls. The efflorescence-producing
frame, but rather as an independent unit, a salts found in masonry are usually sulfates of
curtain wall, or veneer. Therefore, the sodium, potassium, magnesium, calcium, and
primary concern in such cases is with wind or iron. Salts which are chlorides of sodium,
seismic loads, and a safety factor of 8.0 is calcium, and potassium will sometimes appear,
recommended. Where the stone is to be but they are so highly soluble in water that they
subjected to concentrated loading, such as stair will be washed off by rain.
treads or lintels supported only at the ends, a
factor of 10.0 should be used. 8.2 The water-soluble salts causing
efflorescence come from other materials in the
6.4 These safety factors may be adjusted wall. The salts exist in small amounts and are
using sound engineering principles and leached to the surface by water percolating
judgment. through the walls. The most feasible means of
prevention is to stop the entrance of large
6.5 As buildings become taller and amounts of water. Absorption from the face
individual stone-slab veneer becomes larger in will not cause efflorescence unless there are
area, the lateral forces due to wind loads must open joints.
be considered. Wind tunnel tests are often
used on major structures to determine wind 8.3 Quartz-based stones are seldom injured
dynamics and force magnitude. Reinforcement by efflorescence. However, some of the salt
is sometimes necessary for large dimension- crystals may form in the stones' pores near the
slab veneer in critical areas. surface. Crystal growth (recrystallization) in
the pores can cause stress on the walls of the
pores and cause the stone to flake off. If the
7.0 SEISMIC CONSIDERATIONS conditions bringing about this action persist,
scaling may continue and flake off one layer
7.1 Seismic considerations generally require after another. For this to happen, large
that low buildings be stiff, and that tall amounts of water must enter the wall and must
buildings be relatively flexible. Design of contain large amounts of salts.
connections must account for seismically
induced horizontal loading. Local building 8.4 Research indicates that staining and
codes vary and must always be checked to discoloration occurring on new buildings are
determine specific requirements for each area. caused by the action of water percolating
The National Bureau of Standards has published through cement from which soluble alkali salts
two documents on the topic: “Earthquake are leached. The salts are then carried through
Resistant Masonry Construction,” NBS Science the stone, where partially oxidized organic
Series 106; and “Abnormal Loading on matter is picked up. This is then transported to
Buildings and Progressive Collapse: An the surface of the stone, where it is deposited
Annotated Bibliography,” NBS Science Series

 2016 Marble Institute of America Quartz-Based Stone • Page 8-13

as a stain as evaporation of the water takes from the Quarriers or Fabricator before
place. making a final selection.

8.5 This staining phenomenon is similar to

efflorescence except that it involves organic
material. It does not harm the stone other than
leaving an objectionable appearance during or
soon after erection. However, if left alone, the
stain is removed naturally by the action of the
elements, usually in the course of a few
months.

8.6 A considerable amount of water passing

through the stone is necessary to bring out
conspicuous discolorations. Proper pre-
cautions taken during construction of the walls
will usually prevent such troubles. A simple
and helpful expedient is to provide frequent
weep holes in the base course and above shelf
angles. These should be placed in the vertical
joints so they can be sloped upward from the
front to back.

8.7 Stains sometimes appear on the base

course when Quartz-based stone is in contact
with soil, due to the carrying of soluble salts
and some colored soil constituents up through
and to the surface of the stone by capillary
action. Almost all soils contain soluble salts.
Therefore, this staining phenomenon should
disappear when the source of moisture is
eliminated.

8.8 Avoid contact between soil and stone.

Damp-proofing treatments of either a
bituminous or cementitious nature may be
used as a barrier to the groundwater or
construction moisture causing these stains.

9.0 THERMAL EXPANSION

9.1 The thermal expansion of Quartz-based
stone is an important consideration when it is
used with dissimilar materials to form large
units which are rigidly fixed. The coefficient of
thermal expansion varies from one variety to
another; actual thermal characteristics of a
specific Quartz-based stone should be obtained

Page 8-14 • Quartz-Based Stone  2016 Marble Institute of America

Serpentine 1.2.3.3 Additional publications may be
available from the MIA Bookstore–go online at
www.marble-institute.com.
1.0 GENERAL
1.3 Scope of Included Work
1.1 Related Documents
1.3.1 The work to be completed under this
1.1.1 Drawings and general provisions, contract includes all labor and materials
including General and Supplementary required for the furnishing and installation of
Conditions of the Contract and Division I all serpentine work shown or called for on the
Specification sections, apply to this section. contract drawings, specifications, and
addenda.
1.2 Applicable Publications
1.4 Definition of Terms
1.2.1 The following publications listed here
and referred to thereafter by alphanumeric 1.4.1 The definitions of trade terms used in
code designation only, form a part of this this specification shall be those published by the
specification to the extent indicated by the MIA or ASTM International.
references thereto:

1.2.2 ASTM International (ASTM):

1.5 Source of Supply

1.2.2.1 C1526, Standard Specification for 1.5.1 All serpentine shall be obtained from
Serpentine Dimension Stone quarries having adequate capacity and facilities
to meet the specified requirements, and by a
1.2.2.2 C97, Standard Test Methods for firm equipped to process the material promptly
Absorption and Bulk Specific Gravity of on order and in strict accord with
Dimension Stone specifications. The Specifying Authority
(architect, designer, engineer, contracting
1.2.2.3 C99, Standard Test Method for officer, end user, etc.) reserves the right to
Modulus of Rupture of Dimension Stone approve the Material Supplier prior to the
award of this contract. Stone and workmanship
1.2.2.4 C170, Standard Test Method for quality shall be in accordance with Industry
Compressive Strength of Dimension Stone Standards and Practices as set forth by the MIA.

1.2.2.5 C241, Standard Test Method for 1.6 Samples

Abrasion Resistance of Stone Subjected to Foot
Traffic 1.6.1 The Serpentine Contractor shall submit
through the General Contractor, for approval
1.2.2.6 C880, Standard Test Method for by the Specifying Authority, at least two sets of
Flexural Strength of Dimension Stone samples of the various kinds of serpentine
specified. The sample size shall be 1'-0" x 1'-0"
1.2.3 Marble Institute of America and shall represent approximately the finish,
(MIA): texture, and anticipated range of colors to be
supplied. Where necessary to show variations
1.2.3.1 Membership, Products, and Services in color and markings, larger samples or range
Directory sets of samples should be submitted. If
serpentine is to be matched, a minimum of two
1.2.3.2 Dimension Stone Design Manual sets each containing four matched samples
showing proposed veining and range of colors

 2016 Marble Institute of America Serpentine • Page 9-1

in each set must be supplied. Samples Contractor shall obtain and verify
designating finished face shall be clearly labeled measurements at the building. The General
on the back with the name of the serpentine, Contractor shall be responsible for all
and the use for which the serpentine is reasonable assistance to the Serpentine
intended. One set of samples shall be retained Contractor, including the services of an
by the Specifying Authority, and one set shall Engineer, if required, for the establishment of
be returned to the Serpentine Supplier for their levels, bench marks, and the like. The
record and guidance. It is noted herein that Serpentine Contractor shall not be responsible
serpentine is a natural material and will have for determining, making, or verifying (1)
intrinsic variations in color, markings, and design, structural, wind, seismic, or other
other characteristics. Depending on the design loads; (2) engineering estimates; (3)
serpentine selected and quantity required, a plans or specifications; or (4) the types, sizes,
range mockup may be used to further define or locations of anchors, unless specifically
the characteristics of the material. Cost of added to the scope of work.
mockup, if required, shall not be included in
this section. 1.8 Defective Work
1.6.2 Prior to fabrication, an inspection and 1.8.1 Any piece of serpentine showing flaws
approval by the Specifying Authority and/or or imperfections upon receipt at the storage
General Contractor and/or End User of the yard or building site shall be referred to the
finished slabs is recommended to understand Specifying Authority for determination as to
the finish and full range of the material. responsibility and decision as to whether it shall
be rejected, patched, or redressed for use.
1.7 Shop Drawings
1.9 Repairing Damaged Stone
1.7.1 The Serpentine Contractor shall submit
through the General Contractor, for approval 1.9.1 Patching during fabrication. Serpentines
by the Specifying Authority, sufficient sets of have some variation in working qualities.
shop drawings showing general layout, Veins and lines of separation are common. It is
jointing, anchoring, stock thickness, and such standard practice to repair these variations by
other pertinent information. These drawings use of reinforcing, liners, sticking1 together,
shall show all bedding, bonding, jointing and filling with resin or terrazzo, and doing all
anchoring details along with the net piece other work necessary to hold the stone
dimensions of each serpentine unit. One copy together to yield a finished product that is
of approved drawings shall be retained by the usable for architectural purposes. On
Specifying Authority, one copy shall be completion, most repair is visible, with
retained by the General Contractor, and one differences in light reflection. Unlike other
copy returned to the Serpentine Contractor for dimension stones, many varieties of serpentine
fabrication. NO FABRICATION OF that have been reinforced and repaired are
SERPENTINE SHALL BE STARTED UNTIL suitable for use in exterior environments,
SUCH DRAWINGS HAVE BEEN FULLY though not in all situations. Where questions of
APPROVED AND MARKED AS SUCH. The suitability for use are encountered, the MIA
General Contractor shall furnish all field recommends that reliance on past performance
dimensions necessary for fabrication. If is the best guide for making decisions as to
measurements are not established and future performance.
guaranteed in advance, the Serpentine

1Sticking describes the butt edge repair of a broken piece,

now generally done with dowels, cements, or epoxies.
The pieces are “stuck” together; thus “sticking.”

Page 9-2 • Serpentine  2016 Marble Institute of America

1.9.2 Patching during installation. Small chips fibers as a constituent to the white calcite
at the edges and corners of serpentine may be veining common to the variety, and as such,
patched, provided the structural integrity of should be worked “wet” only. The asbestic
the stone is not affected and the patch matches content has no effect on the stone’s use and/or
the color and finish of the stone so that it does maintenance. (Refer also to the Geological
not detract from the appearance. Classification section within this chapter).

2.1.5 Finishes: Finishes listed in the schedule

2.0 MATERIALS shall conform with definitions by MIA or
ASTM International.
2.1 Serpentine
2.1.6 Polished: A mirrorlike, glossy surface
2.1.1 General: All serpentine shall be of kind which brings out the full color and character of
or kinds shown on the Specifying Authority’s the stone. This finish is not recommended for
drawing or as specified herein, conforming to exterior or commercial floor use.
or within the range of approved samples and in
accordance with the characteristics and 2.1.7 Honed: A velvety smooth surface with
working qualities. Care shall be taken in little or no gloss.
selection to produce as harmonious effects as
possible. Patching and waxing2, where 2.2 Setting Mortar (And
permitted under the Marble Institute of Adhesives)
America Group Classifications, shall be
carefully done to conform to the serpentine's 2.2.1 Portland cement shall conform to the
general character and finish. Texture and finish requirements of the Standard Specification for
shall be within the range of sample(s) approved Portland Cement, ASTM C150. White
by the Specifying Authority. portland cement is recommended for white or
light colored serpentine. Nonstaining cement
2.1.2 ASTM C1526 [C97] [C99] [C170] shall conform to the requirements of the
[C241] [C880] See the chart of applicable Standard Specification for Masonry Cement,
ASTM standards and tests in the Appendix. ASTM C91. Molding Plaster (plaster of paris)
shall conform to the requirements of the
2.1.3 Schedule: Serpentine shall be provided Standard Specification for Gypsum Casting
as follows: Plaster and Gypsum Molding Plaster, ASTM
C59/C59M.
2.1.3.1 For (state location on building) (state
name and color) serpentine with a (type) finish, 2.2.2 Sand. All sand shall be clean, free from
supplied by (name company or list several approved organic and other deleterious matter likely to
suppliers). stain the finished work, and shall be screened
as required for the desired results.
2.1.3.2 Provide information as in (1) for
each different serpentine/finish combination 2.2.3 Portland cement shrinkage-
on the project. reducing accelerator used with portland
cement to give it the quick-setting
2.1.4 Asbestos Content. Most serpentine characteristics of plaster of paris, shall be a
stone contains a minor quantity of asbestos

2 Waxing refers to the practice of filling minor surface compounds. It does not refer to the application of past
imperfections such as voids or sand holds with melted wax to make surfaces shinier.
shellac, cabinetmaker’s wax or certain polyester

 2016 Marble Institute of America Serpentine • Page 9-3

nonstaining admixture that will not corrode 2.5.1.3 Use of copper wire for anchors to be
anchors or dowels. installed over 12' off the ground is not
recommended.
2.2.4 Nonstaining adhesive shall be of a type
that will not stain the serpentine, is not affected
by temperature changes or moisture, and 3.0 FABRICATION
adheres firmly to all clean surfaces.
3.1 Beds and Joints
2.3 Pointing Mortar
3.1.1 Bed and joint width shall be determined
2.3.1 Mortar for pointing shall be Type N, as by analysis of anticipated building movements
defined in ASTM C270 (Standard Specification and designed to accommodate such
for Mortar for Unit Masonry). All mixing, movements without inducing undue stresses in
handling, and pacing procedures shall be in the stone panels or joint filler materials.
accordance with ASTM C270. Expansion joints shall be designed and located
to accommodate larger movements.
2.4 Sealants and Backup
Material (If Applicable) 3.2 Backs of Pieces

2.4.1 Where specified (state type or name of 3.2.1 Backs of pieces shall be sawn or roughly
sealant) shall be used for the pointing of joints. dressed to approximately true planes. Back
The backup material used with the sealant shall surfaces shall be free of any matter that may
be (identify material). create staining.

2.4.2 Sealants used for pointing to exclude 3.3 Moldings, Washes, and Drips
moisture and to provide a joint that will remain
plastic for many years, shall be nonstaining. 3.3.1 Moldings, washes, and drips shall be
constant in profile throughout their entire
2.5 Anchors, Cramps, and length, in strict conformity with details shown
Dowels on approved shop drawings. The finish quality
on these surfaces shall match the finish quality
2.5.1 Anchors, cramps, and dowels shall be of the flat surfaces on the building.
made of corrosion-resistant metals. Special
cramps, dowels, and the like shall be used 3.4 Back-Checking and Fitting
where shown on shop drawings, but to Structure or Frame
elsewhere, #8 copper or stainless steel wire
anchors shall be used. It shall be the 3.4.1 Stone coming in contact with structural
responsibility of the Serpentine Contractor to work shall be back-checked as indicated on the
anchor all serpentine securely. For standing approved shop drawings. Stones resting on
serpentine, the following practices usually structural work shall have beds shaped to fit the
prevail: supports as required.

2.5.1.2 A minimum of four anchors should 3.4.2 Maintain a minimum of 1" between
be provided for pieces up to 12 square feet, stone backs and adjacent structure. (Note:
with two additional anchors for each additional many bolted connections will require more
8 square feet of surface area. Shims used to space than this; 2" space may be more
maintain joints shall be plastic. desirable. Large-scale details should illustrate
and control these conditions.)

Page 9-4 • Serpentine  2016 Marble Institute of America

3.5 Cutting for Anchoring, 4.0 SHIPPING AND HANDLING
Supporting, and Lifting Devices
4.1 Packing and Loading
3.5.1 Holes and sinkages shall be cut in stones
for all anchors, cramps, dowels, and other Finished serpentine shall be carefully packed
tieback and support devices per industry and loaded for shipment using all reasonable
standard practice or approved shop drawings. and customary precautions against damage in
However, additional anchor holes shall be transit. No material which may cause staining
drilled at job site by Serpentine Contractor to or discoloration shall be used for blocking or
facilitate alignment. packing.

3.5.2 No holes or sinkages will be provided 4.2 Site Storage

for Serpentine Contractor's handling devices
unless arrangement for this service is made by It shall be the responsibility of the Serpentine
the Serpentine Contractor with the Serpentine Contractor to receive, store, and protect the
Fabricator. serpentine from damage by others after it is
delivered to the job site and prior to its
(NOTE: It is not recommended that lewis pins erection in the building. All serpentine shall be
be used for stones less than 3½" thick). received and unloaded at the site with care in
handling to avoid damage or soiling. If
3.6 Cutting and Drilling for serpentine is stored outside, it shall be covered
Other Trades with nonstaining waterproof paper, clean
canvas, or polyethylene.
3.6.1 Any miscellaneous cutting and drilling
of stone necessary to accommodate other
trades will be done by the Serpentine 5.0 INSTALLATION
Fabricator only when necessary information is
furnished in time to be shown on the shop
5.1 General Installation
drawings and details, and when work can be
executed before fabrication. Cutting and
5.1.1 Installation shall be accomplished with
fitting, due to job site conditions, will be the
competent, experienced Stone Setters, in
responsibility of the Serpentine Contractor.
accordance with the approved shop drawings.
3.6.2 Incidental cutting such as for window
5.1.2 All serpentine pieces shall be identified
frame clips, etc., which is normally not
with a unique piece number corresponding
considered to be the responsibility of the stone
with the number on the shop drawings.
supplier, will be provided only by arrangement
Interchanging of numbered pieces is not
by the General Contractor and Serpentine
permitted.
Contractor with the Serpentine Fabricator.
5.1.3 Serpentine shall be free of any ice or
3.7 Carving and Models frost at time of installation. Salt shall not be
used for the purpose of melting ice, frost, or
All carving shall be done by skilled Stone snow on the stone pieces.
Carvers in a correct and artistic manner, in
strict accordance with the spirit and intent of 5.1.4 Adequate protection measures shall be
the approved shop drawing, or from models taken to ensure that exposed surfaces of the
furnished or approved by the Specifying stone shall be kept free of mortar at all times.
Authority.

 2016 Marble Institute of America Serpentine • Page 9-5

5.2 Mortar Setting portland cement to not more than 3 to 5 parts
of clean, sharp sand mixed quite dry for
5.2.1 Caution with Serpentine Setting tamping. White Portland cement is
Beds. Water expands the intercrystalline recommended for light-colored serpentines.
space in serpentine dimension stone. When it
is being installed in a mortar bed, techniques 5.3.5 Serpentine Tamped. The serpentine
should be employed that minimize the amount shall be tamped with a suitable mallet until
of water at the back face of the stone, and/or firmly bedded to the proper level of the floor.
employment of fogging on the face (to increase
the intercrystalline space at both surfaces 5.3.6 Serpentine Removed. The
uniformly) should be considered. Absent of serpentine shall then be removed and the back
this, the stone could expand at the back face parged with wet cement or the bed sprinkled
temporarily to a larger dimension than the top with water and cement. In the latter
face, causing warping and/or twisting. The procedure, the back of the serpentine shall be
warped stone is difficult, if not impossible, to wet. The method of fully buttering edges of the
return to its original dimensions. serpentine as it is laid is equally approved.

5.2.2 Other methodologies suggest 5.3.7 Joints between the serpentine

employment of installation material that is not pieces shall show an even width when laid and
water-soluble to avoid this potential problem. finished.

5.2.3 This is an installation condition, and 5.3.8 Traffic after Installation. The
should not be construed as a limitation of the floor shall be roped off for 24 hours after
stone’s range of application. Most serpentine installation and then grouted with water and
varieties perform well in wet work white portland cement grout or nonstaining
applications. dry set portland cement grout.

5.3 Floor Serpentine 5.3.9 Timeline for Additional

Cleaning. Cleaning or additional surfacing, if
5.3.1 Floor Preparation. It is the General required, shall not be undertaken until the new
Contractor’s responsibility to clean all subfloor floor is at least seven days old.
surfaces to remove dirt, dust, debris, and loose
particles immediately prior to setting 5.3.10 Thin-Set Method. The thin set
serpentine floor and to ensure that the area to method of installing serpentine tile employing
receive the stone flooring meets the deflection the use of dry set portland cement mortars is
standards of the industry. recommended for thin serpentine tiles
(nominal 3/8" thick) where optimum setting
5.3.2 Curing compounds of any kind shall space is not available. Subfloor shall be clean,
not be used on the slab on which floor smooth finished, and level.
serpentine is to be directly set. If a curing
compound is present, it is the General 5.3.11 Stone dust must be washed off the
Contractor’s responsibility to remove it by back face of stone pavers prior to installation.
scarifying the slab. Apply mortar with flat side of trowel over an
area that can be covered with tile while mortar
5.3.3 Before being set, all serpentine shall be remains plastic. Within ten minutes, and using
clean and free of foreign matter of any kind. a notched trowel sized to facilitate the proper
coverage, comb mortar to obtain an even-
5.3.4 Cement Bed. The cement bed to setting bed without scraping the backing
receive the serpentine tile shall consist of 1 part material. Key the mortar into the substrate

Page 9-6 • Serpentine  2016 Marble Institute of America

with the flat side of the trowel. Comb with the 5.7 Mortar Joints
notched side of the trowel in one direction.
Firmly press stone tiles into the mortar and 5.7.1 Mortar joints shall be raked out to a
move them perpendicularly across the ridges, depth of ½" to ¾". Apply pointing mortar in
forward and back approximately 1/8" to ¼" to layers not exceeding 3/8" and allow each layer
flatten the ridges and fill the valleys. Ensure a to get hard to the touch before the next layer is
maximum mortar thickness of 3/32" between applied. Tool finished joints with a concave
stone tile and backing after stone tile has been tool having a diameter approximately 1/8"
tamped into place. Stone tile shall not be greater than the joint width.
applied to skinned-over mortar. Or
alternatively, back butter the stone tiles to 5.7.2 Care shall be taken to keep expansion
ensure 100% contact. In either method, ensure joints free of mortar, which would
100% contact on 3/8" tile; not less than 80% compromise their function.
contact on ¾" or thicker material, excepting
that all corners and edges of stone tiles must
5.8 Anchorage
always be fully supported, and contact shall
always be 100% in exterior and/or water-
5.8.1 All serpentine shall be anchored or
susceptible conditions.
doweled in accordance with the approved shop
drawings.
5.4 Interior Veneer Serpentine
5.8.2 To the furthest extent possible, all
5.4.1 The serpentine shall be set by spotting anchor preparations in the serpentine units
with gypsum molding plaster or cement shall be shop-applied.
mortar and the use of concealed anchors
secured in the wall backing. 5.8.3 All anchorage devices and anchor
hole/slot fillers shall be in accordance with
5.5 Serpentine Wall Tile ASTM C1242. Care must be taken to ensure
that any holes capable of retaining water are
5.5.1 Individually set thin tile (nominal 3/8" filled after use to prevent water collection and
thick) on vertical surfaces exceeding 8' is not freezing.
recommended. Where thin serpentine tile is
installed, nonstaining adhesives or dry set 5.9 Sealant Joints
mortars may be used as setting beds.
5.9.1 Where so specified, joints requiring
5.6 Toilet and Shower sealant shall be first filled with a closed-cell
Compartments ethafoam rope backer rod. The backer rod
shall be installed to a depth that provides
5.6.1 Stiles and partitions shall be assembled optimum sealant profile after tooling.
with concealed dowel fastenings or corrosion
resistant angles, three in height of stall. 5.9.2 If recommended by the Sealant
Manufacturer, primers shall be applied to the
5.6.2 For ceiling-hung units, metal supporting substrate surfaces according to the
members in ceiling are to be furnished and manufacturer’s directions prior to application
installed by the General Contractor. of the joint sealant.

 2016 Marble Institute of America Serpentine • Page 9-7

5.10 Expansion Joints cause discoloration is expressly prohibited.
Fabricator should be contacted before cleaners
5.10.1 It is not the intent of this other than neutral detergents are used.
specification to make control and expansion-
joint recommendations for a specific project. 6.2 Protection of Finished Work
The Specifying Authority must specify control
and expansion joints and show locations and 6.2.1 After the serpentine work is installed, it
details on drawings. shall be the responsibility of the General
Contractor to see that it is properly and
5.11 Caulking adequately protected from damage and stains
until all trades are finished. This responsibility
5.11.1 Where so specified, joints shall be includes the stone cleaning costs prior to the
pointed with the sealant(s) specified in Section final inspection. The Serpentine Contractor
2.4 after first installing the specified backup will outline the needs for protection, in
material and applying a primer if required, all writing, to the General Contractor. For the
in strict accordance with the printed protection of projecting members, corners,
instructions of the Sealant Manufacturer. window stools and saddles, wood guards using
lumber that will not stain or deface serpentine
5.11.2 All sealants shall be tooled to ensure shall be supplied, installed, and maintained by
maximum adhesion to the contact surfaces. the General Contractor. All nails used shall be
galvanized or nonrusting. Damage to finished
serpentine by other trades shall be repaired or
5.12 Weep Tubes
replaced at the expense of the General
Contractor. Serpentine flooring shall be
5.12.1 Plastic or other weep tubes shall be
adequately protected by the General
placed in joints where moisture may
Contractor against traffic and other damage
accumulate within the wall, such as at base of
with nonstaining materials, without cost to the
cavity, continuous angles, flashing, etc., or as
Serpentine Contractor.
shown on architectural drawings.
6.2.2 All serpentine work in progress shall be
protected at all times during construction by
6.0 CLEANING AND use of a suitably strong, impervious film or
PROTECTION fabric securely held in place.

6.1 Cleaning
PRODUCT
6.1.1 Serpentine shall be shop-cleaned at
the time of final fabrication. It shall also be
DESCRIPTION –
cleaned after installation and all pointing or Serpentine
caulking is completed. All dirt, excess mortar,
weld splatter, stains, and other defacements 1.0 GEOLOGICAL
shall be removed. CLASSIFICATION
6.1.2 All cleaning methods shall be in 1.1 Serpentine. These beautiful and
accordance with ASTM C1515. elegant green stones traditionally have been
grouped in the commercial marble category.
6.1.3 Stiff bristle fiber brushes may be used, However, they are not true marbles. Marble is
but the use of wire brushes or of acid type by geologic definition metamorphic limestone,
cleaning agents and other solutions that may calcium carbonate (CaCO3), and dolomite

Page 9-8 • Serpentine  2016 Marble Institute of America

CaMg(CO3)2. Geologically, the “green yellowish-green? Why is one provided with
marbles,” as they are informally known, are the reinforcing net epoxied to the back and another
low-level metamorphic stone “serpentinite,” of is not? The complex differences are all in the
which the dominant mineral is serpentine. chemistry of rocks, fluids, and variations in
When the mineral name is altered to end with parameters of the metamorphic process.
the suffix “ite,” it becomes the name of the
stone in which it is the main chemical 1.4 A wide range in apparent quality and
constituent. Serpentinite is sometimes performance of these beautiful stones reflects
confused with “green schist,” an entirely the diversity of mineral content and
different rock generally not suitable as consequent variations in the physical properties
dimension stone and rarely seen in the market and durability between the many “green
in part because large, nonfractured blocks are marbles” or serpentinites on today’s market.
difficult to obtain and loose mineral grains This clearly points up the exceptional value of
often preclude achieving suitably polished and the experience and knowledge attained by
durable surfaces. skilled stone technicians.

1.2 The major parent rock of the serpentine 1.5 The geochemistry involved with these
mineral is dark, iron- and magnesium-rich rocks is complex; however, knowing
igneous rock of the oceanic type, with a lesser something about a few of the important
amount of lighter, continental-type rock chemical components of serpentine and their
admixed. When these are intruded with hot, properties greatly aids understanding this often
chemical-rich fluids, the mineral serpentine is perplexing stone group.
formed in beltlike rinds around larger blocks of
oceanic-type, seafloor rock bodies. This action 1.6 Serpentine (Mg3Si2O5(OH)4) is only
takes place when two large segments of Earth’s formed as a metamorphic mineral. It has the
crust crash together, causing regional scale sheeting habit of mica in that it is composed of
metamorphism with injection of chemical-rich thin sheets loosely bound together like pages in
fluids3. Serpentines are thought to be formed a poorly manufactured book. Unlike the well-
very deep, at temperatures up to around known micas, biotite and muscovite,
500°C at a depth called the “Moho,” 4 the serpentine sheets are not elastic, but they are
border marking the transition between the flexible. Large chunks of the mineral have a
outer crust of the Earth and the underlying “soapy” appearance and luster, and feel slippery
upper mantle, at depths of less than 10 to more or “greasy.” The slippery surfaces act as a
than 60 km. lubricant in faulting of the stone. Serpentinites
often occur in contorted and complex shapes
1.3 Slight variations of parent rock mineral because of the flexibility of the sheets, and that
content, the condition of the parent rock, is part of the attraction of the stone. Serpentine
variations in chemistry of the invading fluids, hardness varies from about H=2.5 to 5 on the
and changes in temperature, pressure, and Mohs Scale5, depending on specific parameters
time plus subsequent geologic history, all of its geologic history and other admixed
influence the formation of serpentine stone. minerals. Serpentine does not react to cold,
Frequently asked questions are: Why the great dilute acid.
differences between different shades of green?
Why does one fade and others do not? Why is 1.7 Asbestos. The normal, sheet-like
one very dark green and others light- or “habit” or occurrence of serpentine has been

3 Skinner, B. J. and S. C. Porter, 1992, The Dynamic by a contrast in the velocity of sound through the two
Earth, 2nd ed., John Wiley & Sons, New York, p. 455. chemically different rock compositions.
4 Moho is the accepted slang term for Mohorovicić 5 See Appendix for the Mohs Scale of mineral hardness.

Discontinuity, or the crust/mantle boundary identified

 2016 Marble Institute of America Serpentine • Page 9-9

described, but another form of serpentine is thickness in the figure of the stone. Both
fibrous, and when found in this form it is the carbonate minerals have several properties in
potentially dangerous mineral asbestos. common: they are both H=3 (soft), break in
Properly known as chrysotile serpentine or perfect little rhombohedrons due to inherent
chrysotile asbestos, it has a slightly different weakness in molecular structure, and both are
chemistry than normal serpentine. Additional generally white or sometimes slightly iron-
meta-morphism, and again slight changes in stained.
chemistry, produce the familiar mineral talc.
Since the three forms of serpentine often occur 1.10 The only characteristic that can be used
together, avoid cutting serpentinites dry and to differentiate the two is their reaction to
maintain absolutely meticulous dust control in cold, dilute acid: calcite will effervesce
the shop. vigorously while magnesite does not. Is this
important in dimension stone? Yes, if used as a
1.8 Chrysotile and Talc. The tabletop, one of the traditional uses of highly
transformation of serpentine to chrysotile figured “green marbles.” It will not be easily
(asbestos) to talc is a continuously variable etched by salad vinegar or wine if the carbonate
chemical series and the members are mineral is magnesite. The simple dilute acid
chemically quite similar, but have differing test can be done by anyone; however, if a
molecular geometry. Since they form in surface-masking sealer is used, the acid may not
response to slight differences in metamorphic reach the calcite and produce the typical
pressures and chemistry, all three minerals may reaction. If the sealing agent is trustworthy
be found together. Talc is the softest of over an extended time, the occurrence of one
minerals and used as the example for H=1 on or the other of these carbonates stones should
the Mohs Scale. Talc does not polish. not matter. Consulting with Sealing
Chrysotile may polish if highly compacted and Professionals is recommended.
cut normal to the fibers. Sometimes chrysotile
may become highly siliceous; that is, the 1.11 Carbonate minerals soluble in dilute
mineral is replaced by silica but retains a acids should be used with extreme care in
“ghost” of its fibrous structure. This altered exterior applications where an acid-polluted
variant is known in the semiprecious gem trade atmosphere exists. Likewise, magnesite-rich
as “tiger’s eye” for its striking optical “green marbles” should not be used in exterior
characteristics. Since both talc and asbestos can applications where atmospheric sulfate
be considered undesirable admixtures to a pollution occurs. Magnesite will react to very
commercial-grade “green marble,” they are not dilute sulfuric acid in the moisture and
generally found in more than small or trace recrystallize to water-soluble magnesium
amounts in the better-known serpentines used sulfate (milk of magnesia).
for decades. Their occurrence tends to weaken
the stone, allows moisture penetration, 1.12 Note: Thin-set, cementitious
weathers faster, and should be considered compounds will probably react with any
detrimental in some exterior applications carbonate mineral in the serpertinite stones
where moisture control is difficult. White yielding a failure in attaching thin sheets of
veins in serpentine indicate the presence of talc some green marble.
or asbestos; consequently, the use of such stone
should be minimized in external applications. 1.13 Siderite (FeCO3) is a semi-hard iron
carbonate (H=3.5 to 4.5 on the Mohs Scale)
1.9 Calcite and magnesite (calcium and not uncommon in serpentinites as pale- to
magnesium carbonates, (CaCO3) and (MgCo3) dark-brown masses or veins. It breaks easily
occur in serpentinites, usually as white to off- into parallelogram-shaped fragments, as do
white discrete masses or veins of varying other carbonates, and does not react with cold,

Page 9-10 • Serpentine  2016 Marble Institute of America

dilute acids. It will effervesce in hot, dilute and these two minerals do occur together.
acids, but trying to perform that test is strongly Rapid weathering or loss of the well-polished
discouraged due to the danger of eye damage surface of some “green marbles” may in fact be
when attempting to heat any acid. due to undetected chlorite that occurs as finely
disseminated or small pockets in the serpentine
1.14 Brucite (magnesium hydroxide or that are obscure except to close inspection by
Mg(OH)2) commonly occurs with serpentine, experienced Stone Technicians.
greenschists, chlorite schists, and with talc and
other low-grade metamorphic stone formed 1.18 Albite (NaAlSi3O8). This plagioclase
from dark, high iron- and magnesium-rich feldspar composed of sodium aluminum
igneous rock. Brucite is very soft, about H=2.5 silicate is found in some serpentinites, an
– the same hardness as a human fingernail – expectation given the dark, oceanic-type
thus it is not desirable to have large parent of serpentine. Albite is hard (H=6) and
accumulations or veins of brucite in “green durable, thus a vein of albite is in no way a
marbles.” Brucite is very soluble in cold, dilute detriment unless incipient fractures accompany
acids, but will not effervesce, becoming instead the vein – probably when the vein happens to
a mud-like slurry. be bordered by a very thin chlorite rind.

1.15 Note that since serpentine is formed in 1.19 Magnetite (Fe3O4) iron oxide is often
part from iron- and magnesium-rich parent present in serpentinites due to mineral
rock, the occurrence of other high-Mg segregation that occurs in metamorphic
minerals such as brucite or magnesite and the processes. Magnetite is very hard (H=5.5 to
carbonates of iron, Fe, Ca, and Mg are to be 6.5), harder than common glass. It is magnetic,
expected as minor constituents in black, and when polished, has a metallic luster.
serpentinites.
1.20 Limitations. As a final note to this
1.16 Chlorite [(Mg,Fe)5(Al,Fe)2Si3O10 section regarding the use of serpentine in
(OH) 8] is another green, very soft, sheet-like, building applications, remember that failures
metamorphic mineral. Chlorite, like with the “green marbles” can occur in some
serpentine, brucite, and magnesite, has flexible projects from the physical limitations of
but not elastic sheets loosely bound together. accessory minerals in the stone’s chemical
It has a greasy-feeling surface that facilitates composition. In addition, serpentine’s sheet-
internal slippage in the serpentinite and like, crystalline habits and slippery texture can
greenstone belts. Its color ranges from sometimes cause weakness in slabs, or allow
medium green to a light, yellowish-green, and accelerated surface oxidation in exterior uses
light to medium yellow. Chlorite hardness is where water, temperature extremes, and
H=2 to 2.5, or very soft. Although chlorite sunlight will rapidly degrade some minerals.
may polish, it does not retain polish and is The degree of compaction should always be
prone to rapid surface dulling. Veins of chlorite examined in any stone selection.
weaken the stone when sliced thin and may be
a likely reason to reinforce some slabs with 2.0 COLOR AND VEINING
backup netting and epoxy. Chlorite’s sheeting
habit acts as a plane of weakness along which 2.1 The color, veining, clouds, mottlings,
faulting, slippage, and fracturing will occur, and shadings in serpentine are caused by minor
further weakening a thinly sawn piece. inclusions during the formation or some prior
degradation or weathering of the stone to
1.17 Chlorite may be almost impossible to release staining color. Iron oxides make the
distinguish from serpentine except by pinks, yellows, browns, and reds. Most grays,
hardness, a very difficult distinction to make, blue grays, and blacks are of bituminous origin.

 2016 Marble Institute of America Serpentine • Page 9-11

Greens are caused by micas, chlorites, and 6.0 SIZES
silicates.
6.1 Serpentine is a product of nature with
hundreds of varieties available, each possessing
3.0 TEXTURE distinct characteristics. Little can be done to
alter the condition in which nature presents
3.1 The term “texture,” as applied to these varieties to us. Therefore, size may
serpentine, means size, degree of uniformity, become a limiting factor to consider in the
and arrangement of constituent minerals. selection of serpentine. Check with the Stone
Grains of calcite and other carbonates, the chief Supplier as to the sizes that are available for the
accessory mineral of most serpentines, are specific serpentine.
crystalline and have definite rhombohedral
cleavage which shows bright, reflecting faces 6.2 Selection and delivery can be greatly
on a broken surface. In most serpentines, facilitated by a jointing scheme which permits
however, the grains are elongated in one the use of smaller sizes. A final jointing scheme
direction by the plication (folding) of the beds. should be agreed upon after the serpentine has
been selected and the Serpentine Contractor
has been consulted.
4.0 FINISHES

4.1 Serpentine’s surface may be finished in a 7.0 PRODUCT SAMPLING

number of ways. In general, smooth finishes
tend to emphasize color and veining, whereas 7.1 Serpentine is formed by nature; thus,
rough finishes tend to subdue the veining or there are variations in the tonal qualities of the
markings. stones. However, it is these natural variations
that make serpentines unique, valuable, and
4.2 Typical Finishes for Serpentine highly desirable. Because of these variations,
Are: selection of serpentine should never be made
on the basis of one sample only. It is
4.2.1 Polished: A glossy surface that brings recommended that selection be based on
out the full color and character of the viewing sufficient samples to show the
serpentine. It is not generally recommended complete range of colors of the desired stone.
for exterior use or commercial floors.

4.2.2 Honed: A satin-smooth surface with 8.0 PROPER USAGE TIPS

little or no gloss, recommended for
commercial floors. Recommendation for commercial floors:
1) Minimum ¾" thickness.
2) A honed finish.
5.0 THICKNESS 3) A minimum hardness value of 10 as
measured by ASTM C241.
5.1 Standard nominal thicknesses for
serpentine veneer are ¾", 7/8", 1¼", 1½", Avoid the use of gypsum or molding plaster
and 2". When a serpentine thinner than ¾" is setting spots for the installation of exterior
specified, the ratio between thickness and stone.
overall size and the use of reinforcing backup
materials must be considered. Serpentine
thicker than 2" is usually regarded as cubic
stock.

Page 9-12 • Serpentine  2016 Marble Institute of America

9.0 VENEER CUTTING behavior that may apply to manufactured
building materials. It may not be proper for
9.1 Quarry blocks are reduced to slabs by certain applications.
a gang saw. The gang saw consists of a series of
steel blades set parallel in a frame that moves 1.3 Physical property values of serpentine
forward and backward. The most productive may, however, be measured using the standard
and precision gang saws have diamond-tipped test methods approved by the Dimension Stone
blades with individual hydraulic blade Committee C 18 of ASTM International. The
tensioners. values found when stone is tested for
absorption, density, compressive strength,
9.2 Serpentine blocks can be sawn either abrasion resistance, and flexural strength
perpendicular or parallel to the bedding plane. should be useful for the Designer and Engineer
The perpendicular cut is referred to as an when preliminary construction calculations are
across-the-bed or vein cut. The parallel cut is being made. However, these tests should be
with-the-bed or fleuri cut. Some serpentines made before the project specifications are
produce a pleasing surface when sawed in written, not after. Member companies of the
either direction, and are available as either vein Marble Institute of America are represented on
or fleuri. Other serpentines produce a pleasing this committee and are active in its technical
surface only when sawed in one direction, and work of establishing proper test methods and
are generally available only in that variety. specifications consistent with the latest
technology.

1.4 Physical Properties of Serpentine

TECHNICAL DATA - (This historical data and information is
Serpentine provided only as a guideline. Recommended
minimums or maximums are established and
1.0 PROPERTIES OF provided by ASTM International.)*
SERPENTINE DIMENSION STONE Property Range of Values
1.1 In centuries past, relatively little Compressive Strength (C170)
importance was attached to the ultimate lbs/in²………………………9,000 27,000
physical capabilities of most building materials. Recommended (min): 10,000
Rule of thumb was a common structural design Flexural Strength (C880)
criterion. As a result, the widely used materials lbs/in² .................................. 900-5,000
of the day, for the most part natural rather than Recommended (min): 1,000
manmade materials, were seldom stressed to
their ultimate limits. Modulus of Elasticity** (in millions)
In present-day construction, however, this is lbs/in² ..................................... 2.0-15.0
far from being true. Performance Density, lb/ft3 (C97) .................. 155-180
requirements are daily becoming more Recommended (min): 168
demanding. In striving for taller structures,
greater spans, firmer foundations, thinner Modulus of Rupture (C99) lbs/in².500-2,500
walls and floors, stronger frames, and generally Recommended (min): 1,000
more efficient buildings with more usable Absorption, by weight % (C97). ..... 0.09-1.2
space, today’s Architects and Engineers must Recommended (max): 0.20 exterior, 0.60
get the most out of the materials with which interior
they work.
Abrasion Resistance (Ha) (C241) ..... 25-110
1.2 Serpentine is a product of nature and not Recommended (min): 10
always subject to the rules of consistent

 2016 Marble Institute of America Serpentine • Page 9-13

* Test methods described in current ASTM 4.0 ABRASION RESISTANCE
standards.
** Also known as Young’s Modulus.
(ASTM C241)

4.1 Abrasion resistance is a property of

2.0 STRENGTH (ASTM C170, stone that should be tested per ASTM C241 to
ASTM C880) provide an indication of the stone’s wearing
qualities when exposed to foot traffic.
2.1 The strength of a serpentine is a measure
of its ability to resist stresses. This strength 4.2 The hardness and uniform wearing
depends on several factors: the rift and cleavage qualities of most serpentine varieties make
of the crystals, the degree of cohesion, the them extremely desirable and economically
interlocking of the crystals, and the nature of practical for floors and stairs. Varieties with an
any cementing materials present. ASTM C241 abrasive hardness rating (Ha) of 10
or more are recommended for use as flooring.
A minimum abrasive hardness of 12.0 is
3.0 FIRE RESISTANCE recommended for commercial floors, stair
treads, and platforms subject to heavy foot
3.1 Serpentine is not combustible according traffic. Surfaces of floors constructed with two
to underwriters’ ratings, and so is considered a or more varieties, with Ha differences more
fire-resistant material. Because of its thermal than 5, will not wear evenly and uniformly.
conductivity, however, the heat transfer
through serpentine is fairly rapid. Serpentine is
not considered a highly rated thermal insulator. 5.0 FACTORS AFFECTING
PHYSICAL PROPERTIES
3.2 Underwriters’ fire-resistance ratings
evaluate whether or not a material will burn, 5.1 The ultimate test of a building material
as well as how long it will keep surrounding is its ability to have and maintain the necessary
combustible materials from reaching structural strength, as well as beauty of
temperatures which will cause them to ignite. appearance and low cost of maintenance, over
Pilot plant tests at The Ohio State University the useful life of the structure. Experience has
Pyrotechnics Laboratory indicate that a 10 proven that serpentine meets this test as few
minute rating could be expected from 7/8"- other building materials can.
thick serpentine.
5.2 Illinois Institute of Technology Research
3.3 The use of an insulating material with Institute’s studies have shown that the
serpentine substantially improves the fire durability of serpentine is little affected by
rating, as shown in the following: cycles of weather. This is because of
serpentine’s low rate of absorption. The rates
7/8" serpentine with 1" core of: of moisture absorption of all the serpentines
Paper Honeycomb…………….…..½ hour studied were less than 1 percent by weight.
Cement-Bonded Wood Excelsior…...1 hour Other masonry materials range upward from 4
Autoclaved Cellular Concrete……..1½ hour to 12 percent.
3.4 Methods of estimating fire-resistance
periods of masonry walls and partitions
6.0 SAFETY FACTORS
utilizing component laminae are given in “Fire 6.1 Good engineering practice requires that
Resistance Classifications of Building allowable design stress must provide a margin
Construction,” BMS92, National Bureau of of safety in any structural element. As a
Standards. necessary precaution against such conditions as

Page 9-14 • Serpentine  2016 Marble Institute of America

wind, ice, snow, impact, temperature changes, 6.6 This span for each thickness is the
and imperfect workmanship, these allowable maximum for panels that are supported on two
stresses must be smaller than those which sides only.
produce failure.
6.7 If the panel is supported on all four sides
6.2 Within the accepted limits of safe design and the long side of the panel exceeds twice the
practice, the closer the allowable load is to the short side, use the short span from the table.
ultimate failure load in a structure, the more
efficient is the use of the material and the less 7.0 SEISMIC CONSIDERATIONS
the cost of the construction.
7.1 Seismic considerations generally require
6.3 Contemporary design of buildings, that low buildings be stiff, and that tall
exclusive of the monumental type, does not buildings be relatively flexible. Design of
usually employ serpentine as part of the connections must account for seismically
structural frame, but rather as an independent induced horizontal loading. Local building
unit, a curtain wall, or veneer. Therefore, the codes vary and must always be checked to
primary concern in such cases is with wind determine specific requirements for each area.
load, and a safety factor of 5.0 is
recommended. Where the serpentine is to be 7.2 Additional Readings:
subjected to concentrated loading, such as stair
treads or lintels supported only at the ends, a 7.2.1 The National Bureau of Standards has
factor of 10.0 should be used. published two documents on the topic:
“Earthquake Resistant Masonry Construction,”
6.4 As buildings become taller and NBS Science Series 106; and “Abnormal
individual stone slab veneer becomes larger in Loading on Buildings and Progressive Collapse:
area, the lateral forces due to wind loads must An Annotated Bibliography,” NBS Science
be considered. Wind tunnel tests are often Series 67.
used on major structures to determine wind
dynamics and force magnitude. Reinforcement 7.2.2 The U.S. Army Corps of Engineers has
is sometimes necessary for large-dimension also published TM 5-809-10, “Seismic Design
slab veneer in critical areas. for Buildings.”
6.5 To determine the thickness and size of
panel required:
8.0 EFFLORESCENCE AND
6.5.1 Determine the design and wind load. STAINING

6.5.2 Obtain the flexural strength of the 8.1 Efflorescence is a salt deposit, usually
serpentine under consideration using the white in color that appears on exterior surfaces
ASTM C880 test method. This information of masonry walls. The efflorescence producing
may be available from the Serpentine Supplier. salts found in masonry are usually sulfates of
sodium, potassium, magnesium, calcium, and
6.5.3 Select the unsupported span for each iron. Salts which are chlorides of sodium,
thickness for which the stress is below the calcium, and potassium will sometimes appear,
flexural strength of the serpentine from the but are so highly soluble in water that they will
appropriate table. be washed off by rain.

8.2 The water-soluble salts causing

efflorescence come from other materials in the
wall. The salts exist in small amounts and are

 2016 Marble Institute of America Serpentine • Page 9-15

leached to the surface by water percolating the vertical joints so they can be sloped upward
through the walls. The most feasible means of from the front to the back.
prevention is to stop the entrance of large
amounts of water. Absorption from the face 8.7 Stains sometimes appear on the base
will not cause efflorescence unless there are course when serpentine is in contact with soil,
open joints. or on interior and exterior horizontal surfaces,
due to the carrying of soluble salts and some
8.3 Serpentine is not injured by colored soil constituents up through and to the
efflorescence. However, some of the salt surface of the stone by capillary action. Almost
crystals may form in the pores near the surface. all soils and most of the veining in serpentine
Crystal growth (recrystallization) in the pores contain soluble salts. Therefore, this staining
can cause stress on the walls of the pores and phenomenon is similar to the discoloration
cause the stone to flake off. If the conditions described previously, and will disappear when
bringing about this action persist, scaling may the source of moisture is eliminated. However,
continue and flake off one layer after another. materials from the veining may remain on the
For this to happen, large amounts of water stone’s surface. In walls, provide venting so
must enter the wall and must contain large that moisture can escape through the vents
amounts of salts. rather than through the stone. On horizontal
surfaces, the use of a vapor barrier between the
8.4 Research indicates that staining or setting bed and the concrete slab, or between
discoloration occurring on new buildings is the setting bed and the ground, is
caused by the action of water percolating recommended.
through cement from which soluble alkali salts
are leached. The salts are then carried by the Additional Resources: Refer to Veneer
water through the serpentine, where partially Cutting and Veneer Patterns drawings at the
oxidized organic matter is picked up. This is close of Chapter 7 (Marble and Onyx).
then transported to the surface of the stone,
where it is deposited as a stain as the water
evaporates.

8.5 This staining phenomenon is similar to

efflorescence, except that it involves organic
material. It does not harm the stone other than
leaving an objectionable appearance during or
soon after erection. However, if left alone, the
stain is removed naturally by the action of the
elements, usually in the course of a few
months.

8.6 A considerable amount of water passing

through the stone is necessary to bring out
conspicuous discolorations. Proper
precautions taken during construction of the
walls will usually prevent such troubles. A
simple and helpful expedient is to provide
frequent weep holes in the base course and
above shelf angles. These should be placed in

Page 9-16 • Serpentine  2016 Marble Institute of America

SLATE 1.2.3.1 Membership, Products, and Services
Directory

1.0 GENERAL 1.2.3.2 Dimension Stone Design Manual

1.1 Related Documents 1.2.3.3 Additional publications may be

available from the MIA Bookstore. Go online
1.1.1 Drawings and general provisions, at www.marble-institute.com.
including General and Supplementary
Conditions of the Contract and Division I 1.3 Scope of Included Work
Specification sections, apply to this section.
1.3.1 The work to be completed under this
1.2 Applicable Publications contract includes all labor and materials
required for the furnishing and installation of
1.2.1 The following publications listed here all slate work shown or called for on the
and referred to thereafter by alphanumeric contract drawings, specifications, and
code designation only, form a part of this addenda.
specification to the extent indicated by the
references thereto: 1.4 Definition of Terms
1.2.2 ASTM International (ASTM): 1.4.1 The definitions of trade terms used in
this specification shall be those published by the
1.2.2.1 C629, Standard Specification for MIA or ASTM International.
Slate Dimension Stone
1.5 Source of Supply
1.2.2.2 C120, Standard Test Methods of
Flexure Testing of Slate (Modulus of Rupture, 1.5.1 All slate shall be obtained from quarries
Modulus of Elasticity) having adequate capacity and facilities to meet
the specified requirements, and by a firm
1.2.2.3 C121, Standard Test Method for equipped to process the material promptly on
Water Absorption of Slate order and in strict accord with specifications.
The Specifying Authority (architect, designer,
1.2.2.4 C217, Standard Test Method for engineer, contracting officer, end user, etc.)
Weather Resistance of Slate reserves the right to approve the Material
Supplier for slate prior to the award of this
1.2.2.5 C241, Standard Test Method for contract. Stone and workmanship quality shall
Abrasion Resistance of Stone Subjected to Foot be in accordance with Industry Standards and
Traffic Practices as set forth by the MIA.

1.2.2.6 C880, Standard Test Method for 1.6 Samples

Flexural Strength of Dimension Stone
1.6.1 The Slate Contractor shall submit
1.2.2.7 C1353, Standard Test Method Using through the General Contractor, for approval
the Taber Abraser for Abrasion Resistance of by the Specifying Authority, at least two sets of
Dimension Stone Subjected to Foot Traffic samples of the various kinds of slate specified.
The sample size shall be 1'-0" x 1'-0" and shall
1.2.3 Marble Institute of America represent approximately the finish, texture,
(MIA): and anticipated range of color to be supplied.

© 2016 Marble Institute of America Slate • Page 10-1

One set of samples shall be retained by the 1.8 Defective Work
Specifying Authority, and one set shall be
returned to the Slate Supplier for his/her 1.8.1 Any piece of slate showing flaws or
record and guidance. It is noted herein that imperfections upon receipt at the storage yard
slate is a natural material and will have intrinsic or building site shall be referred to the
variations in color, markings, and other Specifying Authority for determination as to
characteristics. Color variation range is to be responsibility and decision as to whether it shall
only from natural markings in the slate or from be rejected, patched, or redressed for use. Any
the reflective sheen and shadow value of the material in question should not be installed
graining of the natural-cleft textures and prior to inspection and approval.
cleavage planes. Depending on slate selected
and quantity required, a range mockup may be 1.9 Repairing Damaged Stone
used to further define the characteristics of the
material. Cost of mockup, if required, shall not 1.9.1 Chips at the edges or corners may be
be included in this section. patched, provided the structural integrity of
the stone is not affected and the patch matches
1.6.2 Prior to fabrication, an inspection and the color and finish of the natural stone so that
approval by the Specifying Authority and/or it does not detract from the stone’s
General Contractor and/or End User of the appearance.
finished slabs is recommended to understand
the finish and full range of the material.
2.0 MATERIALS
1.7 Shop Drawings
2.1 Slate
1.7.1 The Slate Contractor shall submit
through the General Contractor, for approval
2.1.1 General: All slate shall be of standard
by the Specifying Authority, sufficient sets of
architectural grade, free of cracks, seams,
shop drawings showing general layout,
starts, or other traits which may impair its
jointing, anchoring, stock thickness, and other
structural integrity or function. Inherent color
pertinent information. These drawings shall
variations characteristic of the quarry from
show all bedding, bonding, jointing, and
which it is obtained will be acceptable. Texture
anchoring details along with the net piece
and finish shall be as shown in the sample(s)
dimensions of each slate unit. One copy of the
approved by the Specifying Authority.
approved shop drawings shall be retained by
the Specifying Authority, one copy shall be
2.1.2 ASTM C629 [C120] [C121] [C217]
retained by the General Contractor, and one
[C241] See the chart of applicable ASTM
copy returned to the Slate Contractor for
standards and tests in the Appendix.
fabrication. NO FABRICATION OF SLATE
SHALL BE STARTED UNTIL SUCH
2.1.3 Schedule: Slate shall be provided as
DRAWINGS HAVE BEEN FULLY
follows:
APPROVED AND MARKED AS SUCH. The
Slate Contractor shall not be responsible for
2.1.3.1 For (state location on building) (state
determining, making, or verifying (1) design,
name and color) slate with a (type) finish,
structural, wind, seismic, or other design
supplied by (name company or list several approved
loads; (2) engineering estimates; (3) plans or
suppliers).
specifications; (4) the types, sizes, or locations
2.1.3.2 Provide information as in (1) for
of anchors; or (5) verification of field
each different slate/finish combination in the
dimensions, unless specifically added to the
project.
scope of work.

Page 10-2 • Slate  2016 Marble Institute of America

2.1.4 Finishes: Face finish of all exterior 3.0 FABRICATION
panels should be natural cleft. Sand-rubbed,
honed and other finishes are available, 3.1 Dimensional Limitations
depending on the Slate Supplier. All exposed
edges should be honed to remove saw marks 3.1.1 Slate spandrels, panels, and wall facings
and darken the edge color. are recommended in thicknesses of 1", 1¼",
and sometimes 1½". Standard economical
2.1.4.1 Finishes listed in the schedule shall lengths are up to 6'-6" and widths up to 4'-0".
conform with definitions by the MIA or ASTM Special larger sizes are available to meet design
International. and job conditions on special request. No single
piece is recommended to be over 9'-6" in
2.2 Setting Mortar length or 5'-0" in width. Larger sizes may be
available only under special conditions and
2.2.1 Mortar for setting and pointing shall be limited production.
one part portland cement and one part plastic
lime hydrate to three to five parts of clean, 3.2 Beds and Joints
nonstaining sand. It shall be mixed in small
batches, using potable, non-alkaline water with 3.2.1 Bed and joint width shall be determined
a pH of 7, until it is thoroughly homogeneous, by analysis of anticipated building movements
stiff, and plastic. After mixing, the mortar shall and designed to accommodate such
set for not less than one hour or more than two movements without inducing undue stresses in
hours before being used. the stone panels or joint filler materials.
Expansion joints shall be designed and located
2.3 Pointing Mortar to accommodate larger movements.

2.3.1 Mortar for pointing shall be Type N, as 3.2.2 Some slight lippage and variation is
defined in ASTM C270 (Standard Specification natural and unavoidable where the natural-cleft
for Mortar for Unit Masonry). All mixing, face comes together at the sawed joints.
handling, and placing procedures shall be in
accordance with ASTM C270. 3.2.3 Joints 3/8" or ½" are recommended
between standard size panels, and ¼" and 3/8"
2.4 Sealants and Backup joints at abutting masonry. All joints are to be
water- and moisture-tight and caulked with a
Material (If Applicable)
proper sealant.
2.4.1 Where specified, (state type or name of
sealant) shall be used for the pointing of joints. 3.3 Backs of Pieces
The backup material used with the sealant shall
be (identify material) 3.3.1 Backs of pieces shall be sawn or roughly
dressed to approximately true planes. Back
surfaces shall be free of any matter that may
2.5 Anchors, Cramps, and create staining.
Dowels
3.4 Moldings, Washes, and Drips
2.5.1 All wire anchors, cramps, dowels, and
other anchoring devices shall be nonferrous 3.4.1 Moldings, washes, and drips shall be
metal of the types and sizes shown on approved constant in profile throughout their entire
shop drawings. Doweling natural-cleft slate to length, in strict conformity with details shown
slate is not acceptable. on approved shop drawings. The finish quality

© 2016 Marble Institute of America Slate • Page 10-3

on these surfaces shall match the finish quality conditions, will be the responsibility of the
of the flat surfaces on the building. Slate Contractor.

3.5 Back-checking and Fitting to 3.7.2 Incidental cutting such as for window
Structure or Frame frame clips, etc., which is normally not
considered to be the responsibility of the Stone
3.5.1 Stone coming in contact with structural Supplier, will be provided only by arrangement
work shall be back-checked as indicated on the by the General Contractor and Slate
approved shop drawings. Stones resting on Contractor with the Slate Fabricator.
structural work shall have beds shaped to fit the
supports as required.
4.0 SHIPPING AND HANDLING
3.5.2 Maintain a minimum of 1" between
stone backs and adjacent structure. (Note: 4.1 Packing and Loading
many bolted connections will require more
space than this; 2" space may be more 4.1.1 Finished slate shall be carefully packed
desirable. Large-scale details should illustrate and loaded for shipment using all reasonable
and control these conditions.) and customary precautions against damage in
transit. No material which may cause staining
3.6 Cutting for Anchoring, or discoloration shall be used for blocking or
Supporting, and Lifting Devices packing.

3.6.1 Holes and sinkages shall be cut in stones 4.2 Site Storage
for all anchors, cramps, dowels, and other
tieback and support devices per industry 4.2.1 Upon receipt at the building site, the
standard practice or approved shop drawings. slate shall remain in the factory-prepared
However, additional anchor holes shall be bundles until beginning of the installation.
drilled at job site by Slate Contractor to Bundles shall be staged in an area which is least
facilitate alignment. susceptible to damage from ongoing
construction activity. Once unbundled, the
3.6.2 No holes or sinkages will be provided slate shall be stacked on timber or platforms at
for Slate Contractor’s handling devices unless least 2" above the ground, and the utmost care
arrangement for this service is made by the shall be taken to prevent staining or impact
Slate Contractor with the Slate Fabricator. damage of the slate. If storage is to be
prolonged, polyethylene or other suitable,
(NOTE: It is not recommended that lewis pins nonstaining film shall be placed between any
be used for stones less than 3½" thick.) wood and finished surfaces of the slate.
Polyethylene or other suitable, nonstaining
3.7 Cutting and Drilling for film may also be required as protective
covering.
Other Trades

3.7.1 Any miscellaneous cutting and drilling

of stone necessary to accommodate other 5.0 INSTALLATION
trades will be done by the Slate Fabricator only
when necessary information is furnished in 5.1 General Installation
time to be shown on the shop drawings and
details, and when work can be executed before 5.1.1 Installation shall be accomplished with
fabrication. Cutting and fitting, due to job site competent, experienced Stone Setters, in
accordance with the approved shop drawings.

Page 10-4 • Slate  2016 Marble Institute of America

5.1.2 All slate stone pieces shall be identified receive nonferrous wire anchors are the least
with a unique piece number corresponding expensive and the strongest system. Slots for
with the number on the shop drawings. strap anchors are sometimes acceptable.
Interchanging of numbered pieces is not
permitted. 5.2.4 Rear face of slabs should be at least 1"
from the face of the backup wall. Gauged backs
5.1.3 Slate stone shall be free of any ice or are frequently required where fitting is tight.
frost at time of installation. Salt shall not be Space between back of slate and wall should
used for the purpose of melting ice, frost, or not be filled in completely, but instead spotted
snow on the stone pieces. with approved nonstick mastic compound or
portland cement in spots approximately 6" x
5.1.4 Adequate protection measures shall be 6" located every 18" apart. All shims and
taken to ensure that exposed surfaces of the blocks must be removed.
stone shall be kept free of mortar at all times. Interior panels are set and anchored similarly
to exterior work.
5.2 Mortar Setting and
Anchorage 5.2.5 Panels set in metal frames shall have
rabbeted edges and a sealant for all joints to
5.2.1 All setting shall be done by competent prevent moisture seepage. Hairpin-spring
Stone Setters, in accordance with approved anchors in the back of the panels make slate
shop drawings. easily adaptable to slate-faced precast units and
systems.
5.2.2 Exterior panels shall be anchored to the
masonry wall or framing by at least four bronze 5.2.6 In some selected interior work, small 1'-
wire or other nonferrous metal anchors for 0" x 1'-0" or less ¼" thick gauged panels can
each piece. Standard size anchor is 1/8" to ¼" be applied with a proper adhesive without
wire (depending on the thickness of the stone) anchors. Some interior work may be set with
turned down 1" into a 3/8" round, 1½" deep narrow joints without grout.
hole in the edge of the slate. Each piece must 5.2.7 Individually set thin slate tile (¼" or
be anchored individually for proper 3/8") on vertical surfaces exceeding 15'-0" is
adjustment. Slabs over 12 square feet in surface not recommended.
area shall have at least two additional anchors
every 6 square feet. Relief angles and liners 5.3 Mortar Joints
may be required at normal floor-line distances.
5.3.1 Mortar joints shall be raked out to a
5.2.3 The larger the panel, the more depth of ½" to ¾". Apply pointing mortar in
pronounced and rustic will be the textured layers not exceeding 3/8" and allow each layer
face. Generous tolerance allowances of this to get hard to the touch before the next layer is
natural-textured material will give more speed applied. Tool finished joints with a concave
and ease in installation and a better general tool having a diameter approximately 1/8"
appearance. Anchoring and setting methods greater than the joint width.
should allow for slight adjustments of each
individual panel. Careful piece-to-piece 5.3.2 Care shall be taken to keep expansion
selection should be exercised by the Slate joints free of mortar, which would
Contractor at the job. Individual anchoring compromise their function.
allows proper adjustment and alignment of
each piece in relation to surrounding pieces.
Round anchor holes in the edge of the slate to

© 2016 Marble Institute of America Slate • Page 10-5

5.4 Anchorage 5.7.2 All sealants shall be tooled to ensure
maximum adhesion to the contact surfaces.
5.4.1 All slate shall be anchored or doweled in
accordance with the approved shop drawings. 5.8 Weep Tubes

5.4.2 To the furthest extent possible, all 5.8.1 Plastic or other weep tubes shall be
anchor preparations in the slate units shall be placed in joints where moisture may
shop-applied. accumulate within the wall, such as at base of
cavity, continuous angles, flashing, etc., or as
5.4.3 All anchorage devices and anchor shown on architectural drawings.
hole/slot fillers shall be in accordance with
ASTM C1242. Care must be taken to ensure
that any holes capable of retaining water are
6.0 CLEANING AND
filled after use to prevent water collection and
freezing. PROTECTION

5.5 Sealant Joints 6.1 Cleaning

5.5.1 Where so specified, joints requiring 6.1.1 The Slate Contractor shall keep the slate
sealant shall be first filled with a closed-cell clean with a sponge and clean water. No
ethafoam rope backer rod. The backer rod mortar drippings shall be allowed to dry on the
shall be installed to a depth that provides face of the slate. Upon completion of various
optimum sealant profile after tooling. portions of work, all mortar stains, grease
marks, and dirt should be removed by washing
5.5.2 If recommended by the Sealant with a good grade of cleaner. Flush and clean
Manufacturer, primers shall be applied to the with clear water.
substrate surfaces according to the
manufacturer’s directions prior to application 6.2 Protection of Finished Work
of the joint sealant.
6.2.1 After the slate work has been installed,
5.6 Expansion Joints it shall be the responsibility of the General
Contractor to see that it is properly and
5.6.1 It is not the intent of this specification to adequately protected from damage or stains
make control or expansion joint until all trades are finished. This responsibility
recommendations for a specific project. The includes the stone cleaning costs prior to final
Specifying Authority must specify control or inspection. The Slate Contractor will outline
expansion joints and show location and details the needs for protection, in writing, to the
on drawings. General Contractor.

5.7 Caulking
PRODUCT
5.7.1 Where so specified, joints shall be DESCRIPTION - Slate
pointed with the sealant(s) specified in Section
2.4, after first installing the specified backup
material and applying a primer if required, all
1.0 GEOLOGICAL
in strict accordance with the printed CLASSIFICATION
instructions of the Sealant Manufacturer.
1.1 Slate is a fine-grained, metamorphic
rock exhibiting “slaty” cleavage, which allows

Page 10-6 • Slate  2016 Marble Institute of America

it to be split into thin sheets.1 It is a low-grade 1.4 This realignment and added
metamorphic rock formed from shale, which is compression develops the “slaty” cleavage or
a thin-bedded, fine-grained, clastic cleavability, one of the defining and most useful
sedimentary rock compacted from mud of properties of slate. Because of the realignment
clay-sized silicate clay minerals.2 of the microscopic sheets of clay minerals, the
new cleavage is independent of the former
1.2 How Slate Is Formed. Clay minerals bedding, which can no longer function as a
are often suspended in the turbid waters of parting plane even though it may still be
rivers, lakes, and ponds following heavy rains perfectly visible as a color demarcation. A fresh
and their consequent flooding. When turbidity cleavage surface on slate has a silvery sheen
ceases, clay particles settle to the bottom of the from the microscopic sheets of muscovite and
still water, descending with a rocking, back- chlorite mica that typically develop on cleavage
and-forth motion, like falling leaves. Over surfaces in low-grade metamorphism. Time,
time, the clay accumulates in thin, flat layers oxidation, freezing and thawing, rain, and hail
on the bottom. Additional layers are deposited ultimately fade colors and degrade the stone’s
with each heavy rain or flood event until sheen. This is not a fault–just the normal
gradually many thin layers build up multiple consequence of weathering and not
beds of clay sequences with a water saturation detrimental in most cases unless water
of about 60%. If undisturbed through continual penetrates to allow frost heaving.
sedimentation, compaction occurs, squeezing
out ±95% of the water. With increased burial 1.5 Slate colors are caused by small
to thousands of feet, additional compaction and amounts of iron (red-brown), organic carbon
cementation occurs, and shale is formed. Shale (black), and other additives, minerals, or
readily splits apart at bedding planes, mixtures that yield violet, green, gray, and
sometimes into very thin sheets or thick units. other colors.

1.3 If the resulting shale sequence, a clastic 1.6 Slate quality has been commonly
sedimentary stone, is subjected to regional related to how long it lasts on a roof. Some
compression at a high enough pressure- slates from northern New England are known
temperature-time cycle, then metamorphism to endure at least 250 years. Slate roofs from
occurs. Regional pressure at this level usually Vermont dwellings constructed circa 1740
folds the entire sedimentary sequence, thus the have been recycled to new homes and remain
bedding surfaces will generally, but not always, in good condition, exhibiting only some fading
be at some angle to the pressure. Pressure from surface oxidation of carbonaceous matter
causes the small, flat sheets of clay minerals in that once gave the slate its dark gray hue. Slate
the shale to always realign normal from areas of less intense metamorphism or
(perpendicular to the direction of pressure). slightly less optimal parent rock composition
The metamorphic pressure can be from any several states to the south of Vermont are
direction and may have no relation to former reported to be good for 75 to 100 years.
bedding, only coinciding with bedding as an
accident of fold geometry. 1.7 Phyllite. If the metamorphic pressures
are more intense, the time under pressure is
1 Ref: American Geological Institute. The Glossary of same structure as mica. Clay mineral sheets are carried
Geology, 2nd ed., 1980, Bates and Jackson, eds. in suspension by water, and deposition from suspension
2 Clay, the word, has two distinct meanings: Clay when turbidity ends. Clay is also a size term defined as
minerals are complex silicates, the products of chemical particles less than 1/256 mm or 0.00016" in size.
weathering of feldspar and other silicate minerals. Clay Particles can also be ground-up mineral crystals, rock
minerals have a sheet-like molecular structure, the fragments, and colloidal lithic material, as well as clay
minerals.

© 2016 Marble Institute of America Slate • Page 10-7

longer, or the parent shale composition is silty, both extremes being unsuitable for building
sandy, or contains other foreign matter and purposes. A stone that cannot be used isn’t
entrained chemicals, the resulting meta- “bad,” but there is simply a lot of stone
morphic stone may develop into phyllite, the unsatisfactory for commercial applications.
next higher metamorphic grade. Phyllite tends
to have nonuniform, undulating cleavage 2.0 COLOR AND VEINING
surfaces and often large cubes or crystals of
pyrite (FeS2) that quickly oxidize and bleed 2.1 The color of a slate is determined by its
ugly iron stain, or superhard garnet “knots” that chemical and mineralogical composition. The
occur as lumps and bumps on the wavy gray and bluish-gray colors are due chiefly to
cleavage. Phyllite develops more muscovite the presence of carbonaceous material; many
mica (a hydrous potassium aluminum silicate) other colors are due to iron compounds. Slates
and sericite (iron carbonate or FeCO3) on the containing large proportions of finely divided
cleavages than slate, thus phyllite has an even carbonaceous matter are black. Other colors
more silky silver sheen than ordinary slate. that are found are blue-black, red, green,
purple, mottled, yellow, brown, and buff.
1.8 Schist. If the variables in
metamorphism already mentioned are carried 2.2 Permanence of color has considerable
to the next step, then schist is developed. In importance, for although some slates maintain
schist, secondarily developed minerals from their original color for many years, others
intense metamorphism such as muscovite or change to new shades within a comparatively
biotite mica occur in compact masses and short time.
usually do not have the well-defined, flat
cleavage characteristic of slate, thus schist is 2.3 Some slates tend to fade under the
unsuitable for most traditional uses of slate. influences of the elements. Such changes may
The mica flakes do not lie in flat planes and are be due to the presence of small quantities of
loose enough to easily flake off. Schist is named iron-lime-magnesia carbonates which
for the major, flat mineral in its composition; decompose readily and form a yellow hydrous
for example, muscovite schist, biotite schist, iron oxide, limonite. Therefore, slates are of
hornblende schist, etc. two types: unfading and fading. Unfading color
is not a quality verifiable by any current ASTM
1.9 Unfortunately, some schists and or other test method.
phyllites are sold as slate and when used in
exterior applications result in sheets sloughing 3.0 TEXTURE
off, iron stains bleeding out of the stone, or
actual disintegration of tiles and slabs. Some of 3.1 Differences in conditions of deposition
these “marginal slates” are highly colored and often result in variations in texture of
have interesting textures, but are best reserved successive strata, and such variations make it
for interior, decorative applications and not in possible to trace folds and contortions within
places where there is potential moisture or the quarry. “Ribbons” are dark bands, a fraction
where falling stone is a safety hazard. of an inch to several inches in width,
intersecting blocks of slate at various angles.
1.10 Because the metamorphic process and Cleavage and grain are other characteristics of
resulting stone is so dependent on the right slate that can affect its texture. Cleavage is the
combination of parent stone composition, tendency for stone split with ease in one
location, and the pressure-temperature-time direction. However, many slates have a second
cycle, the products are a continuum from one direction of splitting that is less pronounced
extreme to another–from insufficiently called the grain.
metamorphosed to highly metamorphosed–

Page 10-8 • Slate  2016 Marble Institute of America

4.0 FINISHES Use Thickness
Residential Commercial
4.1 Slate’s surface may be finished in a Foot Traffic Foot Traffic
number of ways. Typical finishes for slate are: Flagging (exterior) ¾" 1"
Thresholds ¾" –7/8" 1" – 1 ¼"
4.1.1 Natural Cleft: A cleavage face formed Tile ¼" – 5/8" ¾" – 1"
when the slate is split into any thickness. Treads 1" – 1 ¼" 1 ½" – 2"

4.1.2 Honed: A satin smooth surface with no

gloss. 6.0 SIZES
4.1.3 Sand Rubbed: A flat, nonreflective 6.1 Slate is a product of nature with many
surface. varieties available, each possessing varying
characteristics. Little can be done to alter the
4.1.4 Tumbled: A weathered, aging finish. condition in which nature presents these
varieties to us. Therefore, size may become a
4.1.5 Machine Gauged (Diamond limiting factor to consider in the selection of a
Gauged): Surface is a level plane with swirl particular slate. The following table represents
marks noticeable. approximate recommended sizes for selected
slate applications.
4.2 The type of finish desired bears some
relationship to final cost, as the smoother Use Length (max) Width (max)
surfaces require more finishing, and Flagging (exterior) 1"-6" 2'-0"
consequently, more time. The most Thresholds 4'-0" 8"
economical finish is the natural cleft. Tile 2'-0" 1'-6"
Treads 5'-6" 1'-6"
4.3 Other finishes, such as bush-
hammered, sandblasted, and planed, 6.2 A jointing scheme which permits the use
may also be available. Some stone finishes can of smaller sizes of slate will greatly facilitate
affect strength and durability. For example, selection and delivery. The MIA
bush-hammered and thermal finishes reduce a Member/Supplier can assist with approval of
stone’s thickness, making it more vulnerable to the final scheme.
weakening from exposure to freeze and thaw
cycles.
7.0 PRODUCT SAMPLING
5.0 THICKNESS 7.1 Slate is formed by nature; thus, there are
variations in the tonal qualities of the stones.
5.1 Standard thicknesses for slate veneers However, it is these natural variations that
are ¾", 1", 1¼", 1½", and 2". Slate tiles are make slate unique, valuable, and highly
available in a variety of thicknesses ranging desirable. Because of these variations, selection
from ¼" to 1". The following table represents of a particular slate should never be made on
approximate recommended thicknesses for the basis of one sample only. It is
selected slate applications: recommended that selection be based on
viewing sufficient samples to show the
complete range of colors of the desired stone.
MIA Members can provide these range
samples.

© 2016 Marble Institute of America Slate • Page 10-9

8.0 PROPER USAGE TIPS 1.2 In present-day construction, however,
this is far from being true. Performance
8.1 Recommendation for commercial requirements are daily becoming more
floors: demanding. In striving for taller structures,
greater spans, firmer foundations, thinner
8.1.1 Minimum ¾" thickness. walls and floors, stronger frames, and generally
more efficient buildings with more usable
8.1.2 A honed or cleft finish. space, today’s Architects and Engineers must
get the most out of the materials with which
8.1.3 A minimum hardness value of 8 as they work.
measured by ASTM C241.
1.3 Slate is a product of nature and not
8.2 Avoid the use of gypsum or molding always subject to the rules of consistent
plaster setting spots for the installation of behavior that may apply to manufactured
stone. building materials.

1.4 Physical property values of slate may,

9.0 TOLERANCES however, be measured using the standard test
methods approved by the Dimension Stone
9.1 Because of the variances in natural cleft Committee C-18 of ASTM International. The
or cleavage, it is recommended that the Slate MIA and Member companies are represented
Quarrier or Fabricator be contacted regarding on the ASTM committee and are active in its
size and thickness tolerances. technical work of establishing proper test
methods and specifications consistent with the
latest technology.
10.0 SOUNDNESS
1.5 Final design should always be based on
specific values for the slate variety ultimately to
10.1 Slate, consisting as it does chiefly of very
be installed. These values may be obtained
small overlapping flakes consolidated under
from the Slate Supplier. All materials are not
pressure, is a strong rock. Most mica slates of
suitable for all uses. In order to avoid mistaken
good commercial quality are highly impervious
selections, tests for material values should be
to moisture.
made prior to final material selection.

1.6 Physical Properties of Slate.

TECHNICAL DATA - Slate (This historical data and information is
provided only as a guideline. Recommended
1.0 PROPERTIES OF SLATE minimums or maximums are established and
DIMENSION STONE provided by ASTM International.)*

1.1 In centuries past, relatively little Property Range of Values

importance was attached to the ultimate Compressive Strength (C170)
physical capabilities of most building materials. lbs/in² ............................ 10,000-15,000
Rule of thumb was a common structural design
criterion. As a result, the widely used materials Flexural Strength (C880)
of the day, for the most part natural rather than lbs/in² ................................ 6,000-5,000
manmade materials, were seldom stressed to
Density, lb/ft3 (C97) .................. 170-190
their ultimate limits.

Page 10-10 • Slate  2016 Marble Institute of America

Property Range of Values combustible materials from reaching
Modulus of Rupture (C120) temperatures which will cause them to ignite.
lbs/in² ............................... 5,500-9,000 Methods of estimating fire-resistance periods
Recommended (min): of masonry walls and partitions utilizing
7,200 along grain, component laminae are given in “Fire
9,000 across grain Resistance Classifications of Building
Construction,” BMS92, National Bureau of
Absorption, by Weight % (C121)….0.1-0.45 Standards.
Recommended (max):
0.25 interior,
0.45 exterior
4.0 ABRASION RESISTANCE
Abrasion Resistance (C241) (Ha)……6.0-10.0 (ASTM C241, C1353)
Recommended (min): 8
4.1 Abrasion resistance is a property of slate
that should be tested per ASTM C241/ C1353
* Test methods described in current ASTM to provide an indication of the slate’s wearing
standards. qualities when exposed to foot traffic.

4.2 The hardness and uniform wearing

2.0 STRENGTH (ASTM C120, qualities of most slate makes it extremely
desirable and economically practical for floors
C880) and stairs. Varieties with an abrasive hardness
(Ha) of 8 or more as measured by ASTM
2.1 Values for modulus of rupture and C241/C1353 tests are recommended for use
flexural strength are determined by testing as flooring exposed to normal foot traffic. A
specimens of slate under laboratory conditions minimum abrasive hardness of 10 is
until they fail. recommended for commercial floors, stair
treads, and platforms subject to heavy foot
2.2 The strength of slate is a measure of its traffic. The abrasion resistance hardness values
ability to resist stresses. This strength depends pertain to foot traffic only. If floors are
on several factors: the amount of mica flakes constructed with two or more stone varieties,
and quartz grains present, the degree of the Ha values of the stones must not differ by
cohesion, and the nature of any cementing more than 5 or the floor surface will not wear
materials present. evenly and uniformly.

3.0 FIRE RESISTANCE 5.0 FACTORS AFFECTING

PROPERTIES (ASTM C121, C217)
3.1 Slate is not combustible according to
underwriters’ ratings, and therefore is 5.1 The ultimate test of a building material
considered a fire-resistant material. Because of is its ability to have and maintain the necessary
its thermal conductivity, heat transfer is fairly structural strength, as well as beauty of
rapid. Most slate is not considered a highly appearance and low cost of maintenance, over
rated thermal insulator. the useful life of the structure. Experience has
proven that slate meets this test as few other
3.2 Underwriters’ fire-resistance ratings building materials can. Studies have shown that
evaluate whether or not a material will burn, the durability of most slates is little affected by
as well as how long it will keep surrounding

© 2016 Marble Institute of America Slate • Page 10-11

cycles of weather. This is because of slate’s low area, the lateral forces due to wind loads must
rate of water absorption. be considered. Wind tunnel tests are often
used on major structures to determine wind
5.2 Currently, two ASTM test methods are dynamics and force magnitude. Reinforcement
unique to slate. ASTM C217 “Standard Test is sometimes necessary for large-dimension
Method for Weather Resistance of Slate,” is a slab veneer in critical areas.
method that is useful in indicating the
differences in weather resistance between
various slates, and should be used to correlate 7.0 SEISMIC CONSIDERATIONS
their durability. ASTM C121 “Standard Test
Method for Water Absorption of Slate,” 7.1 Seismic considerations generally require
provides another element in the comparison of that low buildings be stiff, and that tall
slates. Water absorption testing can be helpful buildings be relatively flexible. Design of
in determining the porosity of a particular connections must account for seismically
slate. induced horizontal loading. Local building
codes vary and must always be checked to
determine specific requirements for each area.
6.0 SAFETY FACTORS The National Bureau of Standards has published
two documents on the topic: “Earthquake
6.1 Good engineering practice requires that Resistant Masonry Construction,” NBS Science
allowable design stress must provide a margin Series 106; and “Abnormal Loading on
of safety in any structural element. As a Buildings and Progressive Collapse: An
necessary precaution against such conditions as Annotated Bibliography,” NBS Science Series
wind, ice, snow, impact, temperature changes, 67. The U.S. Army Corps of Engineers has also
and imperfect workmanship, these allowable published TM 5-809-10, “Seismic Design for
stresses must be smaller than those which Buildings.”
produce failure.

6.2 Within the accepted limits of safe design 8.0 EFFLORESCENCE AND
practice, the closer the allowable load is to the STAINING
ultimate failure load, the more efficient is the
use of the material and the less the cost of the 8.1 Efflorescence is a salt deposit, usually
construction. white in color that appears on exterior surfaces
of masonry walls. The efflorescence-producing
6.3 Contemporary building design does not salts found in masonry are usually sulfates of
usually employ slate as part of the structural sodium, potassium, magnesium, calcium, and
frame, but rather as an independent unit, a iron. Salts which are chlorides of sodium,
curtain wall, or veneer. Therefore, the calcium, and potassium will sometimes appear,
primary concern in such cases is with wind or but they are so highly soluble in water that they
seismic loads, and a safety factor of 5.0 is will be washed off by rain.
recommended. Where the slate is to be
subjected to concentrated loading, such as stair 8.2 The water-soluble salts causing
treads or lintels supported only at the ends, a efflorescence come from other materials in the
factor of 10.0 should be used. These safety wall. The salts exist in small amounts and are
factors may be adjusted using sound leached to the surface by water percolating
engineering principles and judgment. through the walls. The most feasible means of
prevention is to stop the entrance of large
6.4 As buildings become taller and amounts of water. Absorption from the face
individual slate slab veneer becomes larger in

Page 10-12 • Slate  2016 Marble Institute of America

will not cause efflorescence unless there are
open joints.

8.3 Slate is seldom injured by efflorescence.

However, some of the salt crystals may form in
the pores near the surface. Crystal growth
(recrystallization) in the pores can cause stress
on the walls of the pores and cause the stone to
flake off. If the conditions bringing about this
action persist, scaling may continue and flake
off one layer after another. For this to happen,
large amounts of water must enter the wall and
must contain large amounts of salts.

8.4 Calcium carbonate is the least resistant

constituent of slates to long weather exposure,
especially to sulfur fumes, for sulfur trioxide
acting on calcium carbonate forms calcium
sulfate, or gypsum, a mineral which expands
greatly with disruptive effects during
crystallization. Iron carbonate is sometimes
present, and its decomposition not only affects
the slate, but the resulting iron oxides may
cause stains. Iron sulfides may oxidize and form
spots and stains. The oxidation of iron-bearing
minerals, especially ferrous carbonate, often
causes color changes.

© 2016 Marble Institute of America Slate • Page 10-13

NOTES:

Page 10-14 • Slate  2016 Marble Institute of America

SOAPSTONE 1.2.3 Marble Institute of America
(MIA):

1.0 GENERAL 1.2.3.1 Membership, Products, and Services

Directory
1.1 Related Documents 1.2.3.2 Dimension Stone Design Manual
1.1.1 Drawings and general provisions, 1.2.3.3 Additional publications may be
including General and Supplementary available from the MIA Bookstore. Go online
Conditions of the Contract and Division I at www.marble-institute.com.
Specification sections, apply to this section.
1.3 Scope of Included Work
1.2 Applicable Publications
1.3.1 The work to be completed under this
1.2.1 The following publications listed here
contract includes all labor and materials
and referred to thereafter by alphanumeric required for the furnishing and installation of
code designation only, form a part of this all slate work shown or called for on the
specification to the extent indicated by the contract drawings, specifications, and
references thereto: addenda.
1.2.2 ASTM International (ASTM):
1.4 Definition of Terms
1.2.2.1 There currently is no ASTM
Standard Specification for Soapstone 1.4.1 The definitions of trade terms used in
Dimension Stone. this specification shall be those published by the
MIA or ASTM International.
1.2.2.2 C97, Standard Test Methods for
Absorption and Bulk Specific Gravity of 1.5 Source of Supply
Dimension Stone
1.5.1 All soapstone shall be obtained from
1.2.2.3 C99, Standard Test Method for quarries having adequate capacity and facilities
Modulus of Rupture of Dimension Stone to meet the specified requirements, and by a
firm equipped to process the material promptly
1.2.2.4 C170, Standard Test Method for on order and in strict accord with
Compressive Strength of Dimension Stone specifications. The Specifying Authority
(architect, designer, engineer, contracting
1.2.2.5 C241, Standard Test Method for officer, end user, etc.) reserves the right to
Abrasion Resistance of Stone Subjected to Foot approve the Material Supplier for slate prior to
Traffic the award of this contract. Stone and
workmanship quality shall be in accordance
1.2.2.6 C880, Standard Test Method for with Industry Standards and Practices as set
Flexural Strength of Dimension Stone forth by the MIA.

1.2.2.7 C1353, Standard Test Method Using 1.6 Samples

the Taber Abraser for Abrasion Resistance of
Dimension Stone Subjected to Foot Traffic 1.6.1 The Soapstone Contractor shall submit
through the General Contractor, for approval
by the Specifying Authority, at least two sets of
samples of the various kinds of Soapstone
specified. The sample size shall be 1'-0" x 1'-0"
© 2016 Marble Institute of America Soapstone • Page 11-1
and shall represent approximately the finish, dimensions, unless specifically added to the
texture, and anticipated range of color to be scope of work.
supplied. One set of samples shall be retained
by the Specifying Authority, and one set shall 1.8 Defective Work
be returned to the Soapstone Supplier for
his/her record and guidance. It is noted herein 1.8.1 Any piece of Soapstone showing flaws or
that Soapstone is a natural material and will imperfections upon receipt at the storage yard
have intrinsic variations in color, markings, and or building site shall be referred to the
other characteristics. Color variation range is Specifying Authority for determination as to
to be only from natural markings in the responsibility and decision as to whether it shall
Soapstone or from the reflective sheen and be rejected, patched, or redressed for use. Any
shadow value of the graining of the natural- material in question should not be installed
cleft textures and cleavage planes. Depending prior to inspection and approval.
on Soapstone selected and quantity required, a
range mockup may be used to further define
1.9 Repairing Damaged Stone
the characteristics of the material. Cost of
mockup, if required, shall not be included in
1.9.1 Chips at the edges or corners may be
this section.
patched, provided the structural integrity of
the stone is not affected and the patch matches
1.6.2 Prior to fabrication, an inspection and
the color and finish of the natural stone so that
approval by the Specifying Authority and/or
it does not detract from the stone’s
General Contractor and/or End User of the
appearance. Scratches may be hand-sanded
finished slabs is recommended to understand
after which mineral oil shall be re-applied to
the finish and full range of the material.
achieve uniform color.

1.7 Shop Drawings

2.0 MATERIALS
1.7.1 The Soapstone Contractor shall submit
through the General Contractor, for approval
2.1 Soapstone
by the Specifying Authority, sufficient sets of
shop drawings showing general layout,
2.1.1 General: All Soapstone shall be of
jointing, anchoring, stock thickness, and other
standard architectural grade, free of cracks,
pertinent information. These drawings shall
seams, starts, or other traits which may impair
show all bedding, bonding, jointing, and
its structural integrity or function. Inherent
anchoring details along with the net piece
color variations characteristic of the quarry
dimensions of each Soapstone unit. One copy
from which it is obtained will be acceptable.
of the approved shop drawings shall be retained
Texture and finish shall be as shown in the
by the Specifying Authority, one copy shall be
sample(s) approved by the Specifying
retained by the General Contractor, and one
Authority.
copy returned to the Soapstone Contractor for
fabrication. NO FABRICATION OF
2.1.2 See the chart of applicable ASTM
SOAPSTONE SHALL BE STARTED UNTIL
standards and tests in the Appendix.
SUCH DRAWINGS HAVE BEEN FULLY
APPROVED AND MARKED AS SUCH. The
2.1.3 Schedule: Soapstone shall be provided
Soapstone Contractor shall not be responsible
as follows:
for determining, making, or verifying (1)
design, structural, wind, seismic, or other
2.1.4 For (state location on building) (state name
design loads; (2) engineering estimates; (3)
and color) Soapstone with a (type) finish,
plans or specifications; (4) the types, sizes, or
locations of anchors; or (5) verification of field
Page 11-2 • Soapstone  2016 Marble Institute of America
supplied by (name company or list several approved 4.0 SHIPPING AND HANDLING
suppliers).
4.1 Packing and Loading
2.1.5 Provide information as in (1) for each
different Soapstone/finish combination in the 4.1.1 Finished Soapstone shall be carefully
project. packed and loaded for shipment using all
reasonable and customary precautions against
2.1.6 Finishes: Face finish of exterior panels damage in transit. No material which may
should be a fine honed finish. All exposed edges cause staining or discoloration shall be used for
should be honed to remove saw marks and blocking or packing.
darken the edge color. Finished surfaces
should be treated with mineral oil to achieve a
uniform, dark, rich color. 5.0 INSTALLATION

2.1.7 Finishes listed in the schedule shall 5.1 General Installation

conform with definitions by the MIA or ASTM
International. 5.1.1 Installation shall be accomplished with
competent, experienced Stone Setters, in
accordance with the approved shop drawings.
3.0 FABRICATION
5.1.2 All Soapstone stone pieces shall be
3.1 Moldings, Washes, and Drips identified with a unique piece number
corresponding with the number on the shop
3.1.1 Moldings, washes, and drips shall be drawings. Interchanging of numbered pieces is
constant in profile throughout their entire not permitted.
length, in strict conformity with details shown
on approved shop drawings. The finish quality 5.1.3 Soapstone stone shall be free of any ice
on these surfaces shall match the finish quality or frost at time of installation. Salt shall not be
of the flat surfaces on the project. used for the purpose of melting ice, frost, or
snow on the stone pieces.
3.2 Cutting and Drilling For
Other Trades 5.1.4 Adequate protection measures shall be
taken to ensure that exposed surfaces of the
3.2.1 Any miscellaneous cutting and drilling stone shall be kept free of mortar at all times.
of stone necessary to accommodate other
trades will be done by the Soapstone Fabricator 5.2 Expansion Joints
only when necessary information is furnished
in time to be shown on the shop drawings and 5.2.1 It is not the intent of this specification to
details, and when work can be executed before make control or expansion joint
fabrication. Cutting and fitting, due to job site
recommendations for a specific project. The
conditions, will be the responsibility of the
Soapstone Contractor. Specifying Authority must specify control or
expansion joints and show location and details
3.2.2 Incidental cutting, such as for window on drawings.
frame clips, etc., which is normally not
considered to be the responsibility of the Stone 5.3 Caulking
Supplier, will be provided only by arrangement
by the General Contractor and Soapstone 5.3.1 Where so specified, joints shall be
Contractor with the Soapstone Fabricator. pointed with the sealant(s) after first installing
the specified backup material and applying a

© 2016 Marble Institute of America Soapstone • Page 11-3

primer if required, all in strict accordance with PRODUCT
the printed instructions of the Sealant
Manufacturer. DESCRIPTION –
Soapstone
5.3.2 All sealants shall be tooled to ensure
maximum adhesion to the contact surfaces. 1.0 GEOLOGICAL
CLASSIFICATION
1.1 Soapstone currently enjoys a resurgence
6.0 CLEANING AND of popularity for surfaces, kitchenware,
PROTECTION traditional decorative uses, industrial
applications and artistic carvings. The long-
6.1 Cleaning known, unique physical properties and wide
range of colors are once again driving forces in
this recent interest.
6.1.1 The Soapstone Contractor shall keep the
Soapstone clean with a sponge and clean water, 1.2 Soapstone is a metamorphic1 stone or rock
utilizing a neutral detergent if necessary. composed of one or more minerals; however,
in most industrial applications it is almost
6.2 Protection of Finished Work always a mixture of minerals because the
mixture is somewhat harder than single-
6.2.1 After the Soapstone work has been mineral soapstone and mineral mixtures in
installed, it shall be the responsibility of the nature are common, while single mineral
purity is much less common.
General Contractor to see that it is properly
and adequately protected from damage or
1.3 Soapstone texture can vary from
stains until all trades are finished. This massive2 to fibrous or flaky. The best
responsibility includes the stone cleaning costs commercial grades are highly compacted and
prior to final inspection. The Soapstone are not absorbent. It commonly has a “soapy”
Contractor will outline the needs for to slippery and soft feel when the surface is
protection, in writing, to the General unaltered by long use or treated with chemicals
Contractor. or oils.

1.4 Soapstone of commercial value is

quarried in many places around the world: in
far Arctic areas of Canada, Scandinavia, Siberia
and Russia, as well as in Brazil and northeastern
United States.

1.5 Soapstone has been used for thousands

of years by the Inuit people (“Eskimo”) and
others as a medium for carving highly valued
sculpture.

1
Soapstone is always of metamorphic origin, formed by 2
Massive in metamorphic stone means a stone whose
very high pressures and generally from light-colored, constituents are neither oriented in parallel position
low specific gravity, highly silicic (> 60% SiO2; or nor arranged in layers; that is, a stone that does not
quartz) igneous rock. have layering, schistosity, foliation or similar structure.
Page 11-4 • Soapstone  2016 Marble Institute of America
2.0 MINERALOGY amphibole (hornblende etc.) derived from the
alteration of ferromagnesian silicates in igneous
2.1 Minerals commonly found in soapstone rock that, because of the Fe and Mg, may yield
- in general order of abundance: “disfiguring” coloration or blemishes.

2.1.1 Talc: Hydrous magnesium silicate 2.2 Steatite (a.k.a. “steatite talc”): A nearly
Mg3Si4O10(OH)2 is the most abundant mineral obsolete term for soapstone or very pure talc-
component and thus dictates some of the rich rock used for talcum powder and formerly
stone’s characteristic properties like hardness for electrical insulators. Since the term is used
and feel. Since talc defines the Mohs hardness in some older definitions of soapstone, it has
of 1, the softest level of the Mohs scale, found its way into the literature of some
soapstone dominantly composed of talc may be quarries and distributors of soapstone. It is
a bit soft for use as a surface material since it recommended the use of this term be
could easily be scratched by even a fingernail. discontinued as it demands a definition that at
Soapstone is somewhat harder if its best is often vague and confusing. Almost
composition includes one or more of the everyone is familiar with talcum powder (talc),
minerals below. its softness and feel.

2.1.2 Magnesite: Magnesium carbonate

(MgCO3) moderately hard Mohs 3.5 – 4.5, not 3.0 PHYSICAL PROPERTIES OF
soluble in cold, dilute hydrochloric acid, SOAPSTONE:
generally the second most abundant soapstone
mineral. Exhibits excellent rhombohedral 3.1 Hardness: Soapstone used for surfaces
cleavage that is microscopic and not is a soft dimension stone. Mohs hardness 1-4,
detrimental in massive soapstone. Is generally depending on mineral content. The softness is
the white mineral filling “veins” in soapstone a plus: It can be worked with ordinary tooling,
scratches and dings can be eliminated or
and may be responsible for much of the
minimized with ordinary sandpaper, and it is
mottled appearance. forgiving of china–much more so than granite.
It does not have a bothersome preferential
2.1.3 Dolomite: A calcium and magnesium breakage or fracture direction.
carbonate (CaMg(CO3), Mohs hardness of
~3.5, does not react with dilute hydrochloric 3.2 Chemical reactivity: Soapstone is
acid. very inert. It does not react with strong acids
or alkali (basic) solutions. It is non-poisonous
2.1.4 Micas: Muscovite is inert, colorless, and safe to cook in or use around food.
elastic and flaky mica. Less common in
3.3 Heat retention is very high. Soapstone is
soapstone is the dark mica biotite which
unaffected by temperatures from well below
contains iron and magnesium, H=2.5 - 4. zero to above ±2,000° F. Thus it is very useful
as refractory material and is frequently used for
2.1.5 Chlorite is a metamorphic greenish wood burning stoves that use both of these
mica that is soft, non-flexible; and non- properties. It is dimensionally very stable
reactive. It is responsible for the greenish color through a wide range of temperature. The
of some soapstone. ancient Nordic Vikings used flat soapstone
pebbles for pocket hand warmers.
2.1.6 Rare Accessory Minerals: minor to
trace amounts of pyroxene (augite, etc.) and
© 2016 Marble Institute of America Soapstone • Page 11-5
3.4 Absorbency: Since soapstone is a
metamorphic stone formed under high
pressure, it is highly compacted and dense; thus
absorbency is zero or so close to zero that it is
inconsequential, making this stone exceedingly
sanitary as a food preparation surface, as well-
maintained surfaces resist harboring bacterial
growth.

3.5 Color: Usually in the gray to gray-

bluish ranges to mottled white or lighter gray
and greenish hues and/or streaked with
irregular veins of white that may be talc,
magnesite, chlorite, dolomite or again, a
mixture.

3.6 Electrical: Soapstone is non-

conductive and thus is ultra safe for kitchen
counter surfaces. Formerly used for high
voltage electrical insulation.

4.0 FIRE RESISTANCE

4.1 Soapstone is not combustible according
to underwriters’ ratings, and therefore is
considered a fire-resistant material. Because of
its thermal conductivity, heat transfer is fairly
rapid. Most soapstone is not considered a
highly rated thermal insulator.

4.2 Underwriters’ fire-resistance ratings

evaluate whether or not a material will burn,
as well as how long it will keep surrounding
combustible materials from reaching
temperatures which will cause them to ignite.
Methods of estimating fire-resistance periods
of masonry walls and partitions utilizing
component laminae are given in “Fire
Resistance Classifications of Building
Construction,” BMS92, National Bureau of
Standards.

Page 11-6 • Soapstone  2016 Marble Institute of America

TRAVERTINE Additional publications may be available from
the MIA Bookstore. Go online at
www.marble-institute.com.
1.0 GENERAL
1.3 Scope of Included Work
1.1 Related Documents
The work to be completed under this contract
1.1.1 Drawings and general provisions, includes all labor and materials required for the
including General and Supplementary furnishing and installation of all travertine
Conditions of the Contract and Division I work shown or called for on the contract
Specification sections, apply to this section. drawings, specifications, and addenda.
1.2 Applicable Publications 1.4 Definition of Terms
1.2.1 The following publications listed here 1.4.1 The definitions of trade terms used in
and referred to thereafter by alphanumeric this specification shall be those published by the
code designation only, form a part of this MIA or ASTM International.
specification to the extent indicated by the
references thereto:
1.5 Source of Supply
1.2.2 ASTM International (ASTM):
1.5.1 All travertine shall be obtained from
1.2.2.1 C1527, Standard Specification for quarries having adequate capacity and facilities
Travertine Dimension Stone to meet the specified requirements, and from a
firm equipped to process the material promptly
1.2.2.2 C97, Standard Test Methods for on order and in strict accord with
Absorption and Bulk Specific Gravity of specifications.
Dimension Stone
1.5.2 The Specifying Authority (architect,
1.2.3.3 C99, Standard Test Method for designer, engineer, contracting officer, end
Modulus of Rupture of Dimension Stone user, etc.) reserves the right to approve the
Material Supplier for travertine prior to the
1.2.2.4 C170, Standard Test Method for award of this contract.
Compressive Strength of Dimension Stone
1.6 Samples
1.2.2.5 C241, Standard Test Method for
Abrasion Resistance of Stone Subjected to 1.6.1 The Travertine Contractor shall submit
Foot Traffic through the General Contractor, for approval
by the Specifying Authority, at least two sets of
1.2.2.6 C880, Standard Test Method for samples of the various kinds of travertine
Flexural Strength of Dimension Stone specified. The sample size shall be 1'-0" x 1'-0"
and shall represent approximately the vein
1.2.3 Marble Institute of America trend, finish, texture, direction of cut (vein or
(MIA): fleuri), incidence of holes, color of fill (if
applicable), and anticipated range of color to be
1.2.3.1 Membership, Products, and Services supplied. One set of samples shall be retained
Directory by the Specifying Authority, and one set shall
be returned to the Travertine Supplier for
1.2.3.2 Dimension Stone Design Manual his/her record and guidance. It is noted herein
that travertine is a natural material and will

 2016 Marble Institute of America Travertine • Page 12-1

have intrinsic variations in color, markings, and setting drawings shall bear the corresponding
other characteristics. Depending on travertine number marked on an unexposed surface.
selected and quantity required, a range Provisions for the anchoring, doweling, and
mockup may be used to further define the handling of the material, and for the support of
characteristics of the material. (The MIA stone by shelf angles and mechanical anchors,
recommends the use of mockups.) Wherever when required, shall be clearly indicated on the
possible, mockups should remain as a shop drawings. NO FABRICATION OF
completed portion of the project. Where that TRAVERTINE SHALL BE STARTED UNTIL
is not possible, cost of mockup shall not be SUCH DRAWINGS HAVE BEEN FULLY
included in this section. APPROVED AND MARKED AS SUCH. The
Travertine Contractor, unless specifically
1.6.2 Prior to fabrication, an inspection and directed to do so, shall not be responsible for
approval by the Specifying Authority and/or determining, making, or verifying (1) design,
General Contractor and/or End User of the structural, wind, seismic, or other design
finished slabs is recommended to understand loads; (2) engineering estimates; (3) plans or
the finish and full range of the material specifications; or (4) the types, sizes, or
locations of anchors, unless specifically added
1.7 Shop Drawings to the scope of work.

1.7.1 The Travertine Contractor shall submit 1.8 Defective Work

through the General Contractor, for approval
by the Specifying Authority, sufficient sets of 1.8.1 Any piece of travertine showing flaws or
shop drawings showing general layout, imperfections upon receipt at the storage yard
jointing, anchoring, stock thickness, and other or building site shall be referred to the
pertinent information. These drawings shall Specifying Authority for determination as to
show all bedding, bonding, jointing, and responsibility and decision as to whether it shall
anchoring details along with the net piece be rejected, patched, or redressed for use.
dimensions of each travertine unit. One copy
of the approved shop drawings shall be retained 1.9 Repairing Damaged
by the Specifying Authority, one copy shall be Travertine
retained by the General Contractor, and one
copy returned to the Travertine Contractor for 1.9.1 Repair of travertine is an accepted
fabrication. All jointing as shown by the practice and will be permitted. Some chipping
Specifying Authority on the contract drawings is expected; repair of small chips is not
shall be followed, unless modifications are required if it does not detract from the overall
agreed upon in writing, or indicated upon the appearance of the work, or impair the
approved shop drawings. If the contract effectiveness of the mortar or sealant. The
drawings do not show the intent of the jointing, criteria for acceptance of chips and repairs will
it will be the Travertine Contractor’s be per the Marble Institute of America
responsibility to establish the jointing to meet Dimension Stone Design Manual standards
the Specifying Authority’s design intent within unless other criteria are mutually agreed upon
the limitations of the material selected. in writing by the Travertine Contractor and the
Specifying Authority.
1.7.2 The cutting and setting drawings shall be
based upon and follow the drawings and full
size details prepared by the Specifying
Authority, except where it is agreed in writing
or shown on the approved shop drawings that
changes be made. Each stone indicated on the

Page 12-2 • Travertine  2016 Marble Institute of America

2.0 MATERIALS 2.2.2 Travertine should be installed with
white cement. Hydrated lime should conform
2.1 Travertine to ASTM C207 Type S.

2.1.1 General: All travertine shall be of 2.2.3 Sand should comply with ASTM C144.
standard architectural grade, free from cracks,
seams, starts, or other traits which may impair 2.2.4 Mixing water must be potable quality.
its structural integrity or function. Inherent
color variations characteristic of the quarry 2.2.5 Mortar mixes vary in proportions from
from which it is obtained will be acceptable, a hard mixture (1:1:4) to a flexible mixture
providing such is demonstrated in the approved (1:1:9). Hard mixes can be expected to set up
samples. Texture and finish shall be approved stress conditions between the stone and mortar
by the Specifying Authority as shown in the in joints because the thermal coefficient of
samples. mortar expansion is greater than that of stone.
In paving installations, stress is often sufficient
2.1.1.1 If travertine is supplied unfilled, to break the bond between the stone and the
careful attention must be made to the size of substrate. Flexible mortars are not suitable for
any holes present. Holes larger than 2 cm in exterior work.
diameter and/or holes that go through the
stone should be filled with a travertine chip 2.3 Pointing Mortar
cemented below the surface of the stone.
2.3.1 Pointing mortar shall be composed of
2.1.1.2 ASTM C1527 [C97] [C99] [C170] one part white portland cement, one part
[C241] [C880] See the chart of applicable hydrated lime, and six parts white sand passing
ASTM standards and tests in the Appendix. a #16 sieve.

2.1.2 Schedule: Travertine shall be 2.4 Sealants and Backup

provided as follows: Material (If Applicable)
2.1.2.1 For (state location on building) (state 2.4.1 Where specified (state type or name of
name and color) travertine with a (type) finish, sealant) shall be used for the pointing of joints.
supplied by (name company or list several approved The backup material used with the sealant shall
suppliers). be (identify material).

2.1.2.2 Provide information as in (1) for 2.5 Anchors, Dowels, Fastenings

each different travertine/finish combination in
the project. 2.5.1 The Travertine Contractor shall furnish
and set all anchors shown on approved shop
2.1.3 Finishes: Finishes listed in the drawings unless otherwise specified. All
schedule shall conform with definitions by MIA anchors shall be fabricated from Type 304 or
or ASTM International. 316 stainless steel or other suitable nonferrous
metal. Multipart anchors may contain metal
2.2 Setting Mortar other than stainless steel, provided such metal
is not embedded in linkages in the travertine.
2.2.1 Cement used with travertine shall be
white portland cement, ASTM C150, or white 2.6 Stain Prevention
masonry cement, ASTM C91.
2.6.1 Where necessary, specify one or
both of the following systems:

 2016 Marble Institute of America Travertine • Page 12-3

2.6.1.1 Damp-proof unexposed stone 3.4.1 Stone coming in contact with structural
surfaces. Joint surfaces should be damp- work shall be back-checked as indicated on the
proofed only to 1" of finished surface when approved shop drawings. Stones resting on
using nonstaining emulsion. structural work shall have beds shaped to fit the
supports as required.
2.6.1.2 Damp-proof all concrete surfaces on
which travertine will rest. Damp-proof 3.4.2 Maintain a minimum of 1" between
adjacent concrete structure, haunches, etc. stone backs and adjacent structure; however,
many bolted connections will require more
2.7 Adjacent To Water space – 2" may be preferable. Large-scale
details should illustrate and determine these
2.7.1 Travertine used in areas adjacent to conditions.
water that is chemically purified should be
tested to ensure that there is no reaction 3.5 Cutting for Anchoring,
between the stone and the purification Supporting, and Lifting Devices
chemicals (see Exterior Horizontal Surfaces
chapter for more information). 3.5.1 Holes and sinkages shall be cut in stones
for all anchors, cramps, dowels, and other
3.0 FABRICATION tieback and support devices per industry
standard practice or approved shop drawings.
3.1 Beds and Joints However, additional anchor holes shall be
drilled at job site by Travertine Contractor to
3.1.1 Bed and joint width shall be determined facilitate alignment.
by analysis of anticipated building movements
and designed to accommodate such 3.5.2 No holes or sinkages will be provided
movements without inducing undue stresses in for Travertine Contractor’s handling devices
the stone panels or joint filler materials. unless arrangement for this service is made by
Expansion joints shall be designed and located the Travertine Contractor with the Travertine
to accommodate larger movements. Fabricator.

3.2 Backs of Pieces (NOTE: It is not recommended that lewis pins

be used for stones less than 3½" thick).
3.2.1 Backs of pieces shall be sawn or roughly
dressed to approximately true planes. Back 3.6 Cutting and Drilling for
surfaces shall be free of any matter that may Other Trades
create staining
3.6.1 Any miscellaneous cutting and drilling
3.3 Moldings, Washes, and Drips of stone necessary to accommodate other
trades will be done by the Travertine
3.3.1 Moldings, washes, and drips shall be Fabricator only when necessary information is
constant in profile throughout their entire furnished in time to be shown on the shop
length, in strict conformity with details shown drawings and details, and when work can be
on approved shop drawings. The finish quality executed before fabrication. Cutting and
on these surfaces shall match the finish quality fitting, due to job site conditions, will be the
of the flat surfaces on the building. responsibility of the Travertine Contractor.

3.4 Back-Checking and Fitting 3.6.2 Incidental cutting such as for window
frame clips, etc., which is normally not
to Structure or Frame
considered to be the responsibility of the Stone

Page 12-4 • Travertine  2016 Marble Institute of America

Supplier, will be provided only by arrangement 5.0 INSTALLATION
by the General Contractor and Travertine
Contractor with the Travertine Fabricator. 5.1 General Installation
3.7 Carving and Models 5.1.1 Installation shall be accomplished with
competent, experienced Stone Setters, in
3.7.1 All carving shall be done by skilled Stone accordance with the approved shop drawings.
Carvers in a correct and artistic manner, in
strict accordance with the spirit and intent of 5.1.2 All travertine pieces shall be identified
the approved shop drawing, or from models with a unique piece number corresponding
furnished or approved by the Specifying with the number on the shop drawings.
Authority. Interchanging of numbered pieces is not
permitted.
4.0 SHIPPING AND HANDLING
5.1.3 Travertine shall be free of any ice or
4.1 Packing and Loading frost at time of installation. Salt shall not be
used for the purpose of melting ice, frost, or
4.1.1 The cut travertine shall be carefully snow on the stone pieces.
packed for transportation with exercise of all
customary and reasonable precautions against 5.1.4 Adequate protection measures shall be
damage in transit. All travertine under this taken to ensure that exposed surfaces of the
contract shall be loaded and shipped in the stone shall be kept free of mortar at all times.
sequence and quantities mutually agreed upon
by the General Contractor, Travertine 5.2 Setting Mortar
Contractor, and the Travertine Fabricator.
5.2.1 All travertine shall be set accurately in
4.2 Site Storage strict accordance with the contract, approved
shop drawings, and specifications. White
4.2.1 Receipt, storage, and protection of portland cement with a low-alkali content is
travertine prior to and during installation shall recommended.
be the responsibility of the Travertine
Contractor. 5.2.2 When necessary, before setting in the
wall, all stones shall be thoroughly cleaned on
4.2.2 All travertine shall be received and all exposed surfaces by washing with a fiber
unloaded at the site with all necessary care in brush and soap powder, followed by a
handling to avoid damaging and soiling. thorough rinsing with clear water.

4.2.3 Stones shall be stored above the ground 5.2.3 All stone joint surfaces not thoroughly
on nonstaining skids made of cypress, white wet shall be saturated with clear water just
pine, poplar, or yellow pine without an prior to setting.
excessive amount of resin. Chemically treated
wood should not be used. DO NOT USE 5.2.4 Except as otherwise specially noted,
CHESTNUT, WALNUT, OAK, FIR, AND paving stone shall be set in full beds of mortar
OTHER WOODS CONTAINING TANNIN. with all vertical joints flushed full. For vertical
Completely dry travertine shall be covered panels, completely fill all anchor, dowel, and
with nonstaining waterproof paper, clean similar holes, as well as first-course panels in
canvas, or polyethylene. traffic areas up to 36" of finished floor. All bed
and vertical joints shall be 3/8" unless
otherwise noted.

 2016 Marble Institute of America Travertine • Page 12-5

5.2.5 Plastic setting pads shall be placed under applied. Tool finished joints with a concave
heavy stones, column drums, etc., in the same tool having a diameter approximately 1/8"
thickness as the joint, and in sufficient quantity greater than the joint width.
to avoid squeezing mortar out. If anchor
system requires lower stones to carry the Care shall be taken to keep expansion joints
weight of upper stone, then any heavy stones free of mortar, which would compromise their
or projecting courses shall not be set until function.
mortar in courses below has hardened
sufficiently to avoid squeezing. 5.4 Anchorage
5.2.6 Joints can be tooled when initial set has 5.4.1 All travertine shall be anchored or
occurred, or raked out 1" and pointed later. If doweled in accordance with the approved shop
pointed with sealant, the raked depth and drawings.
sealant applications shall conform to
manufacturer’s instructions. 5.4.2 To the furthest extent possible, all
anchor preparations in the travertine units shall
5.2.7 Projecting stones shall be securely be shop-applied.
propped or anchored until the wall above is set.
5.4.3 All anchorage devices and anchor
5.2.8 Only the ends of lugged sills and steps hole/slot fillers shall be in accordance with
shall be embedded in mortar. Balance of joint ASTM C1242. Care must be taken to ensure
shall be left open until finally pointed. that any holes capable of retaining water are
filled after use to prevent water collection and
5.2.9 All cornice, copings, projecting belt freezing.
courses, other projecting courses, steps, and
platforms (in general, all stone areas either
5.5 Sealant Joints
partially or totally horizontal) should be set
with unfilled vertical joints. After setting,
5.5.1 Where so specified, joints requiring
insert properly sized backup material or backer
sealant shall be first filled with a closed-cell
rod to proper depth, and gun in sealant.
ethafoam rope backer rod. The backer rod
shall be installed to a depth that provides
5.2.10 In cold weather, International
optimum sealant profile after tooling.
Masonry Industry All Weather Council
recommendations for setting from 40ºF to
5.5.2 If recommended by the Sealant
20ºF (4ºC to -6ºC) shall be followed, except
Manufacturer, primers shall be applied to the
that no additives shall be used in the setting
substrate surfaces according to the
mortar, and below 20ºF (-6ºC), all work shall
manufacturer’s directions prior to application
be done in heated enclosures.
of the joint sealant.
5.2.11 Individually set thin tile (nominal
3/8") on vertical surfaces exceeding 8' is not 5.6 Expansion Joints
recommended.
5.6.1 Joints shall be adequate to allow for
thermal and structural differential movement.
5.3 Mortar Joints
Filler material for these joints shall be
nonstaining.
5.3.1 Mortar joints shall be raked out to a
depth of ½" to ¾". Apply pointing mortar in
5.6.2 It is not the intent of this specification to
layers not exceeding 3/8" and allow each layer
make control or expansion-joint
to get hard to the touch before the next layer is
recommendations for a specific project. The

Page 12-6 • Travertine  2016 Marble Institute of America

Specifying Authority must specify expansion 6.2 Protection of Finished Work
and control joints and show locations and
details on the drawings. 6.2.1 During construction, tops of walls shall
be carefully covered at night and especially
5.7 Caulking during any precipitation or other inclement
weather.
5.7.1 Where so specified, joints shall be
pointed with the sealant(s) specified in Section 6.2.2 At all times, walls shall be adequately
2.4, after first installing the specified backup protected from droppings.
material and applying a primer if required, all
in strict accordance with the printed 6.2.3 Whenever necessary, substantial
instructions of the Sealant Manufacturer. wooden covering shall be placed to protect the
stonework. Nonstaining building paper or
5.7.2 All sealants shall be tooled to ensure membrane shall be used under the wood.
maximum adhesion to the contact surfaces. Maintain all covering until removed to permit
the final cleaning of the stonework.
5.8 Weep Tubes
6.2.4 The Travertine Contractor will outline
5.8.1 Plastic or other types of weep tubes shall the needs for protection in writing to the
be placed in joints where moisture may General Contractor. The General Contractor
accumulate within the wall, such as at the base shall be responsible for protection of the
of a cavity, continuous angles, flashing, etc., or finished work until all trades are finished. This
as shown on architectural drawings. responsibility includes the stone cleaning costs
prior to the final inspection.
6.0 CLEANING AND 6.2.5 Finishes commonly available are
PROTECTION defined as follows:

6.1 Cleaning 6.2.5.1 Polished: Glossy.

6.1.1 The stone shall be washed with fiber 6.2.5.2 Honed: Dull sheen.
brushes, mild soap powder or detergent, and
clean water, or approved mechanical cleaning 6.2.5.3 Smooth: Smooth with minimum of
process. surface interruption.

6.1.2 Special consideration and protection 6.2.5.4 Plucked: Rough texture.

shall be provided when brickwork or other
masonry is cleaned above the travertine. 6.2.5.5 Machine Tooled: Parallel grooves
Strong acid compounds used for cleaning brick cut in the stone. Available with 4, 6, or 8
will burn and discolor the travertine. grooves to the inch.

6.1.3 Use of sandblasting, wire brushes, or 6.2.5.6 Tumbled: A weathered, aging

acids will only be permitted under special finish.
circumstances approved by Specifying
Authority (architect, engineer, contracting 6.2.5.7 Diamond Gang Sawn:
officer, etc.). Comparatively smooth surface with some
parallel markings and scratches.

 2016 Marble Institute of America Travertine • Page 12-7

PRODUCT materials, especially if used on floors to avoid
snagging high heel shoes.
DESCRIPTION –
Travertine 1.3 The etymology of its name is from the
Italian word “travertino,” derived from the
1.0 GEOLOGICAL ancient Roman name Tibur (now Tivoli), a
town near Rome where travertine forms an
CLASSIFICATION extensive deposit that has been worked for
many centuries. At Tivoli, travertine formed
1.1 Travertine is a varietal name for a kind around hot springs heated by volcanic activity
limestone formed under special conditions of associated with Mt. Vesuvius.
deposition. It is classed as chemical
sedimentary rock and is deposited as 1.4 In a strict sense, travertine is most often1
precipitates in terrestrial (land) environments, considered a precipitate of calcium carbonate2
as opposed to limestone, which is the cemented from saturated, generally warm or hot, fresh,
or recrystallized accumulation of calcareous mineral-laden waters in and around the mouth
organic debris deposited on the sea bottom, of conducting fractures or conduits. One of
then compacted and later cemented. Some several alternative modes of formation can be
marine limestone textures are altered to have wind-agitated pools or ponds saturated with
travertine-like voids before or after deposition calcium carbonate, thus causing precipitates to
and cementation. Marine limestone may or form in concretionary deposits found with
may not have fossils visible to the unaided eye. true, Tivoli-type travertine. Although
If not, then fossil marine microorganisms are travertine often contains plant fragments or
probably present in great abundance together fossils of land animals such as rodents or deer,
with some spores and pollen from terrestrial it will not have marine fossils as do other
plants, algae, and fungi. Because marine travertine-like limestones or marine
limestone fossils are chitinous (the material of limestone.
fingernails), they are preserved even if the
limestone is recrystallized, which obliterates 1.5 Limestone is developed by compaction
calcareous fossils. and cementation of debris from sea shells,
algae, and other marine organisms that extract
1.2 Travertine is valuable in the dimension calcium carbonate from seawater. Subsequent
stone industry because of its striking textural geologic forces can act upon these formations
character—very porous, often cavernous on a to produce travertine-like limestone with
scale of inches, with a diverse palette of light abundant voids and high porosity that mimics
hues and soft earth tones. In part because it is travertine texture. These are marketed as
soft and easily worked, travertine has been a travertine, although they are not the chemical
favorite building and decorative stone from precipitate, Tivoli-type travertine formed
preclassical times to the present. While void around springs. Postdepositional and post-
spaces are distinctive features of travertine, so cementation dissolution, mineral replacement,
too is the character of the stone itself. Void and other chemical changes3 are called
spaces are sometimes filled with waterproof “diagenesis,” and include weathering effects or

1 The American Geological Institute definition of with a slightly different physical geometry of atoms in
travertine allows inclusion of onyx and other its molecules than the more stable molecular geometry
travertine-like limestone. of calcite.
2 The mineral calcite (CaCO ) has several metastable 3 Diagenetic chemical changes can include introduction
3
relatives, minerals that exist for only a short time and of other minerals by invading solutions. Some of these
then revert to the most stable form of CaCO3, which is minerals are chert (hydrous silica), the sulfide minerals
calcite. One such example is aragonite, still CaCO3, but of iron, lead, zinc, and strontium; pyrite (FeS2), galena
(PbS), sphalerite (ZnS), and celestite (SrSO4).

Page 12-8 • Travertine  2016 Marble Institute of America

metamorphic changes caused by pressure, easily dissolved or converted to calcite over
heat, or time at depth together with regional time. Other voids can also be traced to
crustal movement. dissolution of aragonite shell debris in central
Texas travertine.
1.6 Diagenetically altered limestone may
have high porosity, often up to 40% or more. 1.9 Clay Balls. Not uncommon, and
The stone itself may have been formed in very usually undesirable, clay balls are occasionally
shallow waters like tidal flats or near-shore found in travertine. These are lumps of clay
reefs where deposits are exposed at low tide to tumbled by currents until more or less round,
dry in hot sunlight. That drying tends to and deposited in the sedimentation of the
preserve and enhance high porosity, or at least limestone. Clay balls are generally not
provide a well-cemented framework that cemented, will not polish, are soft, and wash
persists even though the void space may be out.
filled with carbonate muds (from tidal flats) or
land-derived mud. Fillings may be washed out 1.10 Tufa. A stone often mistaken for
later or dissolved, leaving voids. This kind of travertine is calcareous tufa. Tufa is a very
limestone is sometimes included in the porous, punky stone that precipitates around
travertine category because its texture having the vents of freshwater springs saturated with
voids resembles that of travertine. However, calcium carbonate that occur on the bottoms of
the mode and environment of formation is salty, landlocked lakes such as Mono Lake in
entirely different than the terrestrial, Tivoli- California and the Dead Sea in Israel.
type travertine.
1.10.1 Calcareous precipitation from fresh-
1.7 Other limestone that ends up with an water occurs when CO3-laden springwater
open travertine texture may be formed by mixes with the saturated salt water of the lake.
secondary solution of the calcium carbonate at Often precipitation is aided by the presence of
great depth—even in formerly dense algal and fungal activity in or around the lake
limestone of low porosity. In this case, void bottom springs. Tufa deposits can take the
space is again developed by dissolution due to form of mounds or spires, giving them, if the
the influx of slightly acidic water that lake level is low enough that they can be seen,
differentially dissolves some of the calcium a crenellated, castle-like appearance with
carbonate. multiple hollow spires that springwater flowed
up through. Spires can be 10 feet high. Tufa is
1.8 A good example is Upper Cretaceous- usually so soft, spongy, irregular, and badly
age (≈70-100 million years old) travertine colored that it generally does not make a usable
limestone from central Texas. This limestone dimension stone. When occasional, rare
was a shallow-water deposit containing deposits are usable, they are marketed as
abundant large marine clams and coiled snails. travertine.
The shells filled with carbonate mud from
marine grasses, and the surrounding matrix and 1.11 Tuff. Another stone, tuff, is frequently
filling was then cemented; later and at depth, confused with tufa. Tuff is a pyroclastic deposit
the calcium carbonate shell was dissolved, (volcanic ash) is not the same as, nor related to,
leaving a “steinkern” (derived from the German, Tufa.
literally meaning “stone nut”) or casting of the
internal shape of the shell cavity plus void space 1.11.1 The primary composition of travertine-
formerly occupied by shells. Differential type stones, except the volcanic tuff, is calcite
solution occurs because these large, heavy or calcium carbonate (CaCO3), with a few
mollusk shells are composed of the mineral having the mineralogical variation of aragonite.
aragonite, a reactive, unstable form of calcite When water precipitates one soluble mineral,

 2016 Marble Institute of America Travertine • Page 12-9

it may also precipitate other minerals or even 4.1.4 Sawn: A comparatively rough surface;
replace calcium carbonate if the chemical can be chat, shot, sand, or diamond sawn.
building blocks are available. Thus most
travertine may contain some hydrous silica 4.1.5 Filled or Unfilled. Travertine for
(chert or flint) or any other soluble salt, other horizontal applications is usually filled with a
minerals, and occasional terrigenous grains of cementitious fill or an epoxy fill similar in color
clastic sediments—clays, quartz silt, or even a to the background color of the travertine.
few grains of quartz sand.
5.0 THICKNESS
2.0 COLOR AND VEINING
5.1 Standard thicknesses for travertine are
2.1 As with most sedimentary rocks, generally ¾", 1¼", 2", and 2 3/8". The
travertine colors range from light buff through recommended thicknesses vary depending on
tan to brown and into shades of red, due to the type of travertine used.
varying amounts of iron oxides in the stone.
Many rocks are colored by iron staining that 5.2 Cutting can be made to exact metric
leached out of rock units above or measurements through conversion of U.S.
superimposed on top of the travertine or Conventional System values to SI International
limestone deposit. System equivalents. Note that as travertine,
like all other natural stone, is cut thinner, its
2.2 Other colors are due to inclusion of tensile strength diminishes.
minerals other than iron and variations in
colors of banding that reflect changes in the 6.0 SIZES
volume or chemistry of invading fluids,
changes in conduits, and alternating wet and 6.1 Travertine is a product of nature with
dry climatic cycles. many varieties available, each possessing
varying characteristics. Little can be done to
3.0 TEXTURE alter the condition in which nature presents
these varieties to us. Therefore, size may
3.1 The term “texture,” as applied to become a limiting factor to consider in the
travertine, means size, degree of uniformity, selection of a particular travertine.
and arrangement of constituent materials.
6.2 MIA Members should be consulted for
4.0 FINISHES specific size information for a particular stone
and its desired use. A jointing scheme that
4.1 Travertine surfaces may be finished in a permits the use of smaller sizes of travertine
number of ways. Typical finishes are: may greatly facilitate selection and delivery.
The MIA Member/Supplier should assist in the
4.1.1 Polished: A glossy surface which final scheme approval.
brings out the full color and character of the
travertine. 7.0 PRODUCT SAMPLING

4.1.2 Honed: A satin smooth surface with 7.1 Travertine is formed by nature; thus,
little or no gloss. there are variations in the tonal qualities of the
stones. However, it is these natural variations
4.1.3 Smooth: An even, flat, level finish, that make travertine unique, valuable, and
with no surface bumps or roughness. highly desirable. Because of these variations,
selection of a travertine should never be made
on the basis of one sample only. It is

Page 12-10 • Travertine  2016 Marble Institute of America

recommended that selection be based on problematic. Holes may appear after
viewing sufficient samples to show the general installation due to thin wall cavities at or near
range of color of the desired stone. MIA the exposed surface of the stone. These cavity
Members can provide these range samples. holes may open because of heavy foot traffic. It
is acceptable practice to fill holes that appear
8.0 PROPER USAGE TIPS after installation.

8.1 Recommendation for commercial

floors: 11.0 FILLING OF TRAVERTINE
8.1.1 Minimum ¾" thickness. 11.1 Travertine may be obtained with its
normal voids unfilled or filled. Although some
8.1.2 A honed finish. finish travertine floors by grinding in place
after installation, this practice is less desirable
8.1.3 A minimum hardness value of 10 as than filling by a Stone Finisher in his shop under
measured by ASTM C241. controlled conditions.

8.2 Avoid the use of gypsum or molding 11.2 Filler. Common materials used for
plaster setting spots for the installation of filling are natural (gray colored) or tinted
exterior stone. portland cement, and clear or colored epoxy
or polyester resins. Unless otherwise specified,
matching colored portland cement is used as
9.0 TOLERANCES filler.

9.1 Because of the many variations in types

of travertine, it is recommended that the TECHNICAL DATA –
Travertine Quarrier or Fabricator be contacted Travertine
regarding size and thickness availability.
Tolerances for fabrication and installation are
the same as for marble dimension stones.
1.0 PROPERTIES OF
TRAVERTINE DIMENSION
STONE
10.0 CUT TYPES
1.1 In centuries past, relatively little
10.1 Due to the bedding planes inherent in importance was attached to the ultimate
most travertine, there are two ways to cut the physical capabilities of most building materials.
material that will give dramatically different Rule of thumb was a common structural design
patterns and color ranges: criterion. As a result, the widely used materials
of the day, for the most part natural rather than
10.1.1 Vein Cut: Vein-cut travertine is cut manmade materials, were seldom stressed to
against the bedding planes, exposing the edge their ultimate limits.
of the formation and giving a very linear
pattern. 1.2 In present-day construction, this is far
from being true. Performance requirements
10.1.2 Fleuri Cut: Sometimes called “cross are daily becoming more demanding. In
cut,” the fleuri cut is parallel to the bedding striving for taller structures, greater spans,
plane, exposing a “flowery,” random pattern. firmer foundations, thinner walls and floors,
Although the stone is strong when cut in this stronger frames, and generally more efficient
method, use in high-traffic paving areas may be buildings with more usable space, today’s

 2016 Marble Institute of America Travertine • Page 12-11

Architects and Engineers must get the most out Property Range of Values
of the materials with which they work.
Modulus of Rupture (C99)
1.3 Travertine is a product of nature and not lbs/in² .............................. 500-1,500
always subject to the rules of consistent Recommended (min):
behavior that may apply to manufactured 700 (interior),
building materials. 700 (exterior)
Absorption, by weight % (C97) .... 0.10-2.5
1.4 Physical property values of travertine Recommended (max): 2.5
may, however, be measured using the standard
test methods approved by the Dimension Stone Abrasion Resistance (C241) (Ha) .........7-25
Committee C18 of the ASTM International. Recommended (min): 10
The MIA and Member companies are
represented on the ASTM committee and are * Test methods described in current ASTM
active in its technical work of establishing standards.
proper test methods and specifications
consistent with the latest technology.
2.0 STRENGTH (ASTM C99,
1.5 Final design should always be based on C170, C880)
specific values for the stone variety ultimately
to be installed. These values may be obtained 2.1 Values for modulus of rupture,
from the Stone Supplier. All materials are not compressive strength, and flexural strength are
suitable for all uses. In order to avoid mistaken ascertained by testing specimens of travertine
selections, tests for material values should be under laboratory conditions until they fail.
made prior to final material selection.
2.2 Size and finish of test samples required
1.6 Physical Properties of Travertine by the standard ASTM test methods may not
(This historical data and information is reflect the actual performance of stone when
provided only as a guideline. Recommended used in lesser thicknesses or with other finishes
minimums or maximums are established and that affect strength. For this reason, the
provided by ASTM International.)* Modulus of Rupture (C99) test is
recommended when the stone to be used will
Property Range of Values be two or more inches thick. The Flexural
Strength (C880) test is recommended when
Compressive Strength (C170)
the stone thickness will be less than two inches.
lbs/in² .......................... 5,000 -10,500
Recommended (min):
2.3 The strength of a travertine is a measure
5,000 (interior),
of its ability to resist stresses. The two “cuts” of
7,500 (exterior)
travertine will exhibit different strength
Flexural Strength (C880) characteristics and must be tested for the type
lbs/in² ............................. 600-1,500 of cut being used on the project. Travertine’s
Recommended (min): strength depends on several factors, such as the
500 (interior), rift and cleavage of the calcite crystals, the
500 (exterior) degree of cementation, the interlocking of the
calcite crystals, and the nature of any
Modulus of Elasticity (in millions) cementing materials present.
lbs/in² ............................... 2.0-15.0
Density, lb/ft3 (C97) ................ 140-165
Recommended (min): 144

Page 12-12 • Travertine  2016 Marble Institute of America

3.0 FIRE RESISTANCE 5.0 FACTORS AFFECTING
PROPERTIES
3.1 Stone is not combustible according to
underwriters’ ratings, and therefore is 5.1 The ultimate test of a building material
considered a fire-resistant material. Because of is its ability to have and maintain the necessary
its thermal conductivity, heat transfer is fairly structural strength, as well as beauty of
rapid. Most stone is not considered a highly appearance and low cost of maintenance, over
rated thermal insulator. the useful life of the structure. Experience has
proven that stone meets this test as few other
3.2 Underwriters’ fire-resistance ratings building materials can. Studies have shown that
evaluate whether or not a material will burn, the durability of most stones is little affected by
as well as how long it will keep surrounding cycles of weather. This is because most have a
combustible materials from reaching low rate of moisture absorption.
temperatures which will cause them to ignite.
Methods of estimating fire-resistance periods 5.2 Exterior travertine paving is not re-
of masonry walls and partitions utilizing commended for environments where deicing
component laminae are given in “Fire chemicals may be used to melt ice and snow,
Resistance Classifications of Building because these chemicals will damage most
Construction,” BMS92, National Bureau of travertine.
Standards.
6.0 SAFETY FACTORS
4.0 ABRASION RESISTANCE 6.1 Good engineering practice requires that
(ASTM C241) allowable design stress must provide a margin
of safety in any structural element. As a
4.1 Abrasion resistance is a property of necessary precaution against such conditions as
stone that should be tested per ASTM C241 to wind, ice, snow, impact, temperature changes,
provide an indication of the stone’s wearing and imperfect workmanship, these allowable
qualities when exposed to foot traffic. stresses must be smaller than those which
produce failure.
4.2 The hardness and uniform wearing
qualities of most varieties of travertine make 6.2 Within the accepted limits of safe design
them extremely desirable and economically practice, the closer the allowable load is to the
practical for floors and stairs. Varieties with an ultimate failure load, the more efficient is the
abrasive hardness (Ha) of 10 or more as use of the material and the less the cost of the
measured by ASTM C241 tests are construction.
recommended for use as flooring exposed to
normal foot traffic. A minimum abrasive 6.3 Contemporary building design does not
hardness of 12 is recommended for usually employ stone as part of the structural
commercial floors, stair treads, and platforms frame, but rather as an independent unit, a
subject to heavy foot traffic. If floors are curtain wall, or veneer. Therefore, the
constructed with two or more stone varieties, primary concern in such cases is with wind or
the Ha values of the stones must not differ by seismic loads, and a safety factor of 8.0 is
more than 5 or the floor surface will not wear recommended. Where the stone is to be
evenly and uniformly. subjected to concentrated loading, such as stair
treads or lintels supported only at the ends, a
factor of 10.0 should be used. These safety
factors may be adjusted using sound
engineering principles and judgment.

 2016 Marble Institute of America Travertine • Page 12-13

6.4 As buildings become taller and 8.3 The most feasible means of prevention is
individual stone slab veneers becomes larger in to stop the entrance of large amounts of water.
area, the lateral forces due to wind loads must Absorption from the face will not cause
be considered. Wind tunnel tests are often efflorescence unless there are open joints.
used on major structures to determine wind
dynamics and force magnitude. Reinforcement 8.4 However, some of the salt crystals may
is sometimes necessary for large-dimension form in the pores near the surface. Crystal
slab veneer in critical areas. growth (recrystallization) in the pores can put
stress on the walls of the pores and cause the
stone to flake off. If the conditions bringing
7.0 SEISMIC CONSIDERATIONS about this action persist, scaling may continue
and flake off one layer after another. For this to
7.1 Seismic considerations generally require happen, large amounts of water must enter the
that low buildings be stiff, and that tall wall and must contain large amounts of salts.
buildings be relatively flexible. Design of
connections must account for seismically 8.5 Avoid contact between soil and stone.
induced horizontal loading. Local building Damp-proofing treatments of either a
codes vary and must always be checked to bituminous or cementitious nature may be
determine specific requirements for each area. used as a barrier to the ground water or
The National Bureau of Standards has published construction moisture causing these stains.
two documents on the topic: “Earthquake
Resistant Masonry Construction,” NBS Science
Series 106; and “Abnormal Loading on
Buildings and Progressive Collapse: An
Annotated Bibliography,” NBS Science Series
67. The U.S. Army Corps of Engineers has also
published TM 5-809-10, “Seismic Design for
Buildings.”

8.0 EFFLORESCENCE AND

STAINING

8.1 Efflorescence is a salt deposit, usually

white in color that occasionally appears on
exterior surfaces of masonry walls. The
efflorescence-producing salts found in masonry
are usually sulfates of sodium, potassium,
magnesium, calcium, and iron. Salts which are
chlorides of sodium, calcium, and potassium
will sometimes appear, but they are so highly
soluble in water that they will be washed off by
rain.

8.2 The water-soluble salts causing

efflorescence come from other materials in the
wall. The salts exist in small amounts and are
leached to the surface by water percolating
through the walls.

Page 12-14 • Travertine  2016 Marble Institute of America

INSTALLATION – methods of fabrication. Refer to the specific
stone description chapter for fabrication
GENERAL tolerances.
INFORMATION
2.4 Labor Assignment. In most regions
1.0 INSTALLATION OF of the United States, the labor body responsible
DIMENSION STONE for installing a stone product will change
pending if the stone product is a tile or a cut-
1.1 This chapter of the Marble Institute of to-size product. Labor jurisdiction practices
America’s Dimension Stone Design Manual vary regionally and locally, so research is
includes general notes and references that encouraged to ascertain which labor group is
apply to the installation of natural stone in both assigned the field installation of a given
horizontal (walking surfaces, interior and product.
exterior) and vertical (cladding, interior and
exterior) applications. Chapter 14 references
issues specific to the installation of horizontal 3.0 RELATED MATERIALS
surfaces, and chapter 15 references issues 3.1 Setting Bed Mortars
specific to the installation of vertical surfaces.
This chapter should be used in conjunction 3.1.1 Portland Cement Mortar (Thick
with either chapter 14 or 15 to provide a Bed)
complete discussion of the process if installing
natural stone in a particular application. 3.1.1.1 Portland cement mortar is a mixture
of portland cement and sand, roughly in
proportions of 1:3 for floors, and of portland
2.0 STONE PRODUCT cement, sand, and lime in proportions of
DEFINITIONS 1:5:½ to 1:7:1 for walls.
2.1 Tile. A stone tile is a thin, flat piece of
3.1.1.2 Installation Methods. Portland
natural stone used as finishing material, with a cement mortar is suitable for most surfaces and
thickness ranging from ¼" to 5/8" (6 to 16 mm) ordinary types of installation. The thick bed,
inclusive, and having no dimension greater 3/8" to 1½" on walls and nominally 1¼" on
than 2’-0” (610 mm). Tiles are normally floors, facilitates accurate slopes or planes in
supplied in typical sizes, with all atypical pieces the finished work. There are two equivalent
being field cut to fit. methods recognized for installing stone tile
with a portland cement mortar bed on walls,
2.2 Cut-to Size. Cut-to-size stone ceilings, and floors:
products, also referred to as “slab stock” stone
products, are custom fabricated pieces of 3.1.1.2.1 The method (ANSI A108.1A) that
natural stone with any dimension exceeding requires that the stone be set on a mortar bed
the limits defined in the tile definition above. that is still plastic.
Fabrication of these products normally occurs
in a shop setting, where each piece is custom 3.1.1.2.2 The method (ANSI A108.1B) that
fabricated to fit, but partial fabrication can also requires the stone to be thin set on a cured
occur in the field at the time of installation. mortar bed with dry set or latex portland
cement mortar or a two-part, 100% solids
2.3 Tolerances. Natural stone tiles and epoxy.
cut-to-size products may have different
fabrication tolerances due to their different

 2016 Marble Institute of America Installation/General Information • Page 13-1

3.1.1.3 Suitable Backings. Portland 3.1.2.4 Suitable backings. When
cement mortars can be reinforced with metal properly prepared and in sound structural
lath or mesh, backed with membranes, and condition, suitable backings include plumb and
applied on metal lath over open studding on true masonry, concrete, gypsum board,
walls or on rough floors. They are structurally cementitious backer units, terrazzo, cured
strong, not affected by prolonged contact with portland cement mortar beds, brick, ceramic
water, and can be used to plumb and square tile, and dimension stone. Existing control
surfaces installed by others. Suitable backings, joints including divider strips shall be
when properly prepared, are brick or concrete maintained. Polished, glossy, honed, or
masonry unit, concrete, wood or steel stud smooth backup surfaces shall be roughened by
frame, rough wood floors, plywood floors, sanding or scarifying. See ANSI A108.01
foam insulation board, gypsum board, and General Requirements: Subsurfaces and
gypsum plaster. The one coat method may be Preparations by Other Trades.
used over masonry, plaster, or other solid
backing that provides firm anchorage for metal 3.1.2.5 Installation and Material
lath. Specifications. Complete installation and
material specifications are contained in ANSI
3.1.1.4 Installation and Material A108.5 and A118.1.
Specifications. Complete installation and
material specifications are contained in ANSI 3.1.3 Latex-Portland Cement Mortar
A108.1 for installation when bed is still plastic, [Thin Bed (ANSI A118.4)]
and for cured float bed and thin set
applications. 3.1.3.1 Latex-Portland cement mortar
is a mixture of portland cement, sand, and
3.1.2 Thin-Set Mortar [Thin Bed (ANSI special latex additives which is used as a bond
A118.1)] coat for setting stone tile.

3.1.2.1 Thin-set mortar is a mixture of 3.1.3.2 Installation Methods. The uses

portland cement with sand and additives of latex-portland cement mortar are similar to
providing water retention, and is used as a those of thin-set mortar. It is less rigid than
bond coat for setting stone. portland cement mortar.

3.1.2.2 Installation Methods. Thin-set 3.1.3.3 When latex-portland cement

mortar is suitable for use over a variety of mortar is used to install stone in a wet area
surfaces. The stone should be properly tamped that may not thoroughly dry out in use (e.g.,
in place into the mortar, which will be one swimming pools and gang showers, etc.), it is
layer as thin as 3/32" after tamping. Thin set recommended that the complete installation be
mortar has excellent water and impact allowed to dry out thoroughly (cure) before
resistance, can be cleaned with water, is exposure to water. Consult the thin-set
nonflammable and good for exterior work. manufacturer for curing instructions. Latexes
vary considerably, and the directions of the
3.1.2.3 Thin-set mortar is available as a latex Manufacturer must be followed
factory-sanded mortar to which only water explicitly.
need be added. Cured thin set mortar is not
affected by prolonged contact with water, but 3.1.3.4 Suitable backings (See 3.1.2.4
does not form a water barrier. It is not above).
intended to be used in trueing or leveling the
substrate surfaces as tile is being installed. 3.1.3.5 Installation and Material
Specifications. Complete installation

Page 13-2 • Installation/General Information  2016 Marble Institute of America

specifications and material specifications are time, there are few masonry cement mortars
contained in ANSI A108.5 and ANSI A118.4. produced labeled “nonstaining.”

3.1.4 Epoxy Mortar (ANSI A118.3) 3.1.6 Setting Bed. White portland cement
with low alkali content is required for all light
3.1.4.1 This is a thin bed mortar system colored stone varieties.
employing epoxy resin and epoxy hardener
portions. A two- part, 100% solid epoxy is to 3.2 Grouts Between Stones
be used as the setting bed for green colored
marbles, serpentine stones susceptible to 3.2.1 Commercial Portland Cement
warping and for any fiberglass mesh-backed Grout (“Unsanded Grout”)
tiles.
3.2.1.1 Commercial portland cement
3.1.4.2 Suitable Backings. Acceptable grout is a mixture of portland cement and
substrates, when properly prepared and other ingredients, producing a water-resistant,
structurally sound, include concrete, APA dense, uniformly colored material. There are
rated Exposure 1 underlayment grade two types: white and gray. Damp curing is
plywood*, steel plate, and ceramic tile. advantageous for both wall and floor types.
Application is made in one thin layer. Pot life,
adhesion, water cleanability before cure, and 3.2.2 Sand-Portland Cement Grout
chemical resistance vary with manufacturer. (“Sanded Grout”)

3.1.4.3 Installation and Material 3.2.2.1 Sand-portland cement grout is

Specifications. Complete installation and an on the job mixture of one of the following
material specifications are contained in ANSI proportions: one part portland cement to one
A108.6 and ANSI A118.3. part clean, fine-graded sand (ASTM C144)
used for joints up to 1/8" wide; 1:2 for joints
3.1.5 Limestone Setting Mortar. Cement up to ½" wide; and 1:3 for joints over ½"
used with limestone shall be white portland wide. Up to 1/5 part lime may be added.
cement, ASTM C150, or white masonry Damp curing is necessary. Sand-portland
cement, ASTM C91. Nonstaining cement shall cement grout should be applied with caution
contain not more than 0.03% of water-soluble over softer varieties of stone with honed or
alkali when determined in accordance with polished finishes because it may scratch the
procedure 15, calculation 16 of ASTM C91 or stone surface.
Federal Specification SS-C181C. However, if
a large amount of normal cement has been used 3.2.3 Polymer Modified Portland
in the backup material, and if an effective water Cement Grout (ANSI A118.7)
barrier has not been provided between the
stone and the backup, the use of nonstaining 3.2.3.1 Polymer modified portland
cement may not prevent all discoloration. cement grout is a mixture of any of the
Discoloration will disappear as the stone dries. preceding grouts with polymer admixtures.
The Indiana Limestone Institute recommends a The common polymer types are latex and
1:1:6 (portland: lime: sand) or Type N mortar acrylic. This grout is suitable for all
be used with Indiana Limestone. At the present installations subject to ordinary use and for
most commercial installations. The use of

*APA- The Engineered Wood Association,

Voluntary Production Standard PS 1-07 Structural
Plywood.

 2016 Marble Institute of America Installation/General Information • Page 13-3

polymer additives in portland cement grout 3.5.4 Oil based organic sealants should
increases the flexibility of the grout and not be used in conjunction with natural stone
reduces the permeability. Consult the grout products because they may stain the stone.
and polymer manufacturers for specific
instructions. It is less absorptive than regular 3.5.5 Sealing the Face of the Stone.
cement grout. Nothing in this section is intended to imply that
actual sealing of the faces of the stones is a
3.2.4 Colored Grouts recommended practice. If any sealer coating is
specified for any natural stone material, advice
3.2.4.1 Many manufacturers offer grouting should be sought in detail from qualified Stone
materials in colors. Architects and Designers Suppliers or Installers (See Ch 3, pg. 3-5,
find them pleasing for aesthetic reasons. Since section 5.10).
some stones are more porous than others, test
to determine the stability of the relationship 3.5.6 Joint Filler. An important feature in
between the colored joint filler and the stone the determination of the joint sealant is the
before proceeding. Make certain pigments selection of the joint filler. The joint filler, or
contained in the colored grout do not stain the backing rod, performs three functions:
stone.
3.5.6.1 Controls both the depth and shape of
3.3 Sand. Sand should comply with ASTM the sealant.
C144.
3.5.6.2 Provides support for the caulking
3.4 Water. Mixing water must be potable sealant when it is being compressed during
quality. tooling.

3.5 Stone Sealants, Backing Rods, and 3.5.6.3 Acts as a bond breaker for the sealant
Caulking to prevent three sided adhesion. (Three-sided
adhesion can result in failure of the sealant.)
3.5.1 Building sealants are normally
covered as a separate section in project 3.5.7 Waterproof sealant is applied in joints
specifications, and in most trade areas the that have backing rods inserted. The backing
installation of sealants is not in the trade rods can be porous (open cell), or nonporous
jurisdiction of Marble Mechanics and (closed cell), and are typically made of
Stonemasons. Grouting is almost always in the polyethylene or polystyrene rope.
stone specification.
3.5.8 Consult the Sealant,
3.5.2 Silicone Sealants. Some grades of Waterproofing, and Restoration
silicone sealants are not recommended by their Institute guidelines for further information
manufacturers for application on high calcite on proper joint sealant design, selection, and
content materials. Consult the Sealant installation.
Manufacturer’s technical recommendation
before applying a given sealant to calcite 3.6 Expansion Joints
materials.
3.6.1 Design and Location. Expansion
3.5.3 Severe service areas (patios, decks, and/or movement joints are essential for the
traffic surfaces) should be caulked with success of stone installations. Various methods
materials having sufficient abrasion resistance. require proper design and location of
Consult Sealant Manufacturer’s technical expansion joints as shown in “Method EJ171,”
recommendations for sealants in these areas. from the Tile Council of North America

Page 13-4 • Installation/General Information  2016 Marble Institute of America

Installation Handbook. Because of the limitless certain substrate materials used in wet areas
conditions and structural systems in which may be subject to deterioration from moisture
stone can be installed, the Specifying Authority penetration.
shall show locations and details of expansion
joints on project drawings. 3.7.1.1 Wet Areas. “Wet areas” are stone
surfaces that are either soaked, saturated, or
3.6.2 Final Design. It is not the intent of this subjected to moisture or liquids (usually
manual to make control and expansion joint water), e.g., gang showers, tub enclosures,
recommendations for a specific project. The showers, laundries, saunas, steam rooms,
Architect must specify control and expansion swimming pools, hot tubs, and exterior areas.
joints and show location and details on
drawings. 3.7.2 Self Leveling Underlayments.
Gypsum-based and self-leveling underlayments
3.6.3 Sealants. Where so specified, joints are not recommended for use with stone
shall be pointed with the sealant(s) referred to paving, except in conjunction with an
in this section, after first installing the specified approved water-proofing/crack isolation
backup material and applying a primer if membrane (See ANSI A118.10-118.12). If
required, all in strict accordance with the using this method, extreme caution in
printed instructions of the Sealant following the Manufacturer’s recommended
Manufacturer. procedure is required.

3.6.4 All sealants shall be tooled to ensure 3.7.2.1 Installation of stone paving directly
maximum adhesion to the contact surfaces. over gypsum based underlayment is not
recommended.
3.6.5 Expansion joint sealants include
silicone, urethane, and polysulfide. Generally, 3.8 Deflection of Surfaces
urethane sealants are recommended for
horizontal stone surfaces because of their 3.8.1 General Contractor
resistance to abrasion and penetration. Responsibility. It is the responsibility of
the General Contractor to provide a rigid,
3.6.6 Silicone sealants may be used in code-compliant structure that is adequate to
expansion joints on both exterior and interior accommodate the stone and its anchorage
vertical stone surfaces. Some one part, including all associated loads and forces.
mildew-resistant silicone sealants are
formulated with fungicide for sealing interior 3.8.2 Cast-in-Place Concrete Floors.
joints in showers and around tubs, sinks, and Design substrate for total load deflection not
plumbing fixtures. exceeding L/360, as measured between
control or expansion joints.
3.6.7 Sealants should comply with ASTM
C920. 3.8.3 Frame Construction. The subfloor
areas over which stone tile is to be applied must
3.7 Substrate Limitations be designed to have a deflection not exceeding
L/720 of the span. In calculating load, the
3.7.1 Moisture Penetration. The weight of the stone and setting bed must be
performance of a properly installed stone considered.
installation is dependent upon the durability
and dimensional stability of the substrate to 3.8.3.1 Strongbacks, cross-bridging or
which it is bonded. The user is cautioned that other reinforcement shall be used to limit

 2016 Marble Institute of America Installation/General Information • Page 13-5

differential deflection between adjacent Architectural drawings will show approximate
framing members. depth and relief of carving. Carving shall be
left as it comes from the tool, unless otherwise
3.8.4 Maximum variation of a concrete specified.
slab or subfloor shall not exceed 1/8" in 10'
from the required plane when thin set systems
are applied. 6.0 FIELD REPAIR
6.1 During the progress of construction,
3.8.5 Allowance should be made for live
changes are often necessary to accommodate
load and impact, as well as all dead load,
other trade and design revisions. These changes
including weight of stone and setting bed.
may require job site cutting and some finishing
of stone, and this can be executed satisfactorily
3.8.5.1 Mortar Bed Weight. For
by qualified mechanics.
estimating purposes, mortar bed weight can be
approximated as 0.75 lb per square foot per
6.2 Repair or patching is sometimes
each 1/16” of thickness.
necessary due to damage of material either on-
site or in transit. By allowing these repairs to
3.8.5.2 Stone Weight. For estimating
be made on-site, progress of the job can be
purposes, stone weight can be approximated as
maintained, thus aiding the successful
1 lb per square foot per each 1/16” of
completion of the work. Repairs should not
thickness.
detract from the desired appearance or
strength of the completed installation.
4.0 SAMPLES
7.0 STONE TILE INSTALLATION
4.1 The Dimension Stone Contractor shall
furnish samples of the various dimension stones REFERENCES. The Marble Institute of
to be used. Samples shall indicate the extremes America has participated in the Tile Council
of color, veining, and marking the stone of North America’s (TCNA) development of
supplied to the project will have. Samples the Handbook for Ceramic, Glass, and Stone
must be approved or rejected in their entirety, Installation. This document is reprinted every
without stipulation. year, although the handbook committee meets
only biennially, so substantial revisions are
4.2 Pending the scope of the installation and likely to appear only biennially. This
the variability of the stone product, a full-sized handbook includes a section dedicated to the
mockup may be required to adequately installation of stone tile products. The details
demonstrate the range of the material’s color are not duplicated in the Marble Institute of
and character. America publications. Contact the TCNA
(www.tcnatile.com) or the Marble Institute of
4.3 Inspection of supplied material to America’s Book Store to obtain a copy of the
evaluate compliance with approved samples handbook.
shall be done at a viewing distance of not less
than 6’-0” with natural lighting. 8.0 TRIPS AND TRAPS
OCCURRING IN THE
5.0 CARVING INSTALLATION OF NATURAL
STONE
5.1 All carving called for shall be performed
by skilled workmen in strict accordance with 8.1 Stone Tiles with Fiberglass Mesh
approved full-size details or models. Backing. Producers frequently apply a fiber

Page 13-6 • Installation/General Information  2016 Marble Institute of America

mesh reinforcement to the back surfaces of sealants to ensure compatibility with stone. It
stone tiles and slabs to reduce breakage and also is recommended that either an exemplar
increase safety when handling large slabs. project be identified using the same stone and
Caution should be used when using a stone that sealant components with satisfactory results,
has a fiberglass mesh backing applied on the or a testing regimen be employed to verify
back face. The fiberglass, having been bonded compatibility.
to the stone with a resinous (commonly epoxy)
adhesive, will not bond adequately with 8.5 Efflorescence. Efflorescence is a salt
cementitious products. Only epoxy products, deposit, usually white in color that appears on
or products specifically made for fiberglass by exterior surfaces of stone walls and floors. The
the manufacture, should be used when efflorescence is produced by salts leached to
installing stone with fiberglass mesh backing. the surface of the stone by water percolating
through the stone backup and joints. The most
8.2 Green Colored Stone. Avoid the use feasible means of prevention is to stop the
of water-based adhesive when installing certain entrance of large amounts of water. If the
green marbles and/or serpentines. Some of conditions bringing about the efflorescence
these stones may warp through absorption of continue, scaling may occur and flake off
water from the setting bed. (Water drawn into successive layers. For this to happen, large
the stone is held to the crystals by surface amounts of water must continue to enter
energy. This force tends to widen the behind the stone and must contain large
intercrystalline space and thereby expand the amounts of salts.
wet side.) TCA Methods F116 and F142 should
be used with an adhesive that is not water- 8.6 Down Washed Lighting. The use of
based. down washed lighting, in which the path of
light is nearly parallel to the face of the wall
8.3 Travertine Voids. Travertine surface, is a popular choice in both interior and
flooring, particularly fleuri cut (also called exterior designs. This lighting style will
“cross-cut) will have voids occurring just below exaggerate lippage, textural surface variation,
the finished surface of the material. Since these and even warpage due to the extremely
voids are concealed by a thin shell of stone elongated shadow lines caused by the slight
material, they do not get filled in the factory angle of incidence. Material and installation
filling process. Once in service, concentrated which are within industry tolerances may
loads (particularly from wheels or spike heels) appear to be outside of tolerances due to the
will fracture the thin shell of stone, exposing accentuation of the lighting technique.
the void below. Several iterations of re-filling Inspection of areas receiving down washed
travertine floors in place can be expected until lighting shall be done with the down washed
these voids are all discovered. This is lighting turned off.
essentially a “break-in” process for this
particular material. 8.7 Reflection. It is almost impossible to
uniformly read light reflection on a polished or
8.4 Sealant Staining. Some elastomeric high-honed-finish installation due to the
sealants contain oil-based plasticizers to reduce natural characteristics of dimension stone.
their modulus and increase their Due to the heterogeneous composition of
extension/compression capability. The natural stones, variable mineral hardness exists
plasticizers can wick into stone perimeters, within the stone, producing variable
causing darkening of the edge (picture framing) reflectivity of light energy. Most stones, and
and accelerated dirt collection on the stone especially travertine marbles and honed-finish
face. Caution should be used in specifying surfaces, will appear to reflect light unevenly.

 2016 Marble Institute of America Installation/General Information • Page 13-7

 9.2 Guidelines. While every effort has
8.8 Polishing Wheel Marks. Polishing been made to produce accurate guidelines,
wheel marks or other scratches caused during they should be used only with the independent
fabrication are unacceptable on honed or approval of technically qualified persons.
polished stone.

9.0 NOTES REGARDING

INSTALLATION CHAPTERS
9.1 Stone Detail Symbol. The details in
this manual have been drawn to represent
generic stone rather than a particular type of
stone, and a symbol was used that makes the
stone easily identifiable.

NOTES:

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NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

HORIZONTAL 2.1.4 It must be noted that these classifications
are for the stone’s abrasion resistance only. The
SURFACES stone’s finish (polished, honed, thermal, etc.)
will wear with traffic. Polished finish on stones
1.0 INTRODUCTION with abrasion indices ≤ 20.0 are not suitable for
most moderate and any heavy-traffic areas.
1.1 Installation Methods. Stone paving Thermal finish is recommended for exterior
can be installed by several methods. paving.
Consideration should be given to the various
features of each method in making a selection 2.1.5 Stone with high abrasion resistance
for a specific installation. See illustrations of (≥20.0) will generally maintain a polished
installation examples at the close of this surface in foot traffic areas. Stones with lesser
section. abrasive indices are likely to abrade in service,
and generally perform better if supplied in
1.2 For additional information, refer honed finish.
to Chapter 13, INSTALLATION - GENERAL
INFORMATION. 2.1.6 Limitations. If several varieties of
stone are used together, care should be taken
to ensure that the abrasive hardness (Ha) of the
2.0 DESIGN CRITERIA stones is similar. Proper testing (ASTM C241
or ASTM C1353) should be performed on each
2.1 Class of usage establishes the abrasion stone variety. If the abrasion resistance of
resistance a stone requires to withstand the foot either stone is < 20.0, then the difference in
traffic requirements of the project. This is abrasion resistance between the stone shall be
determined according to the ASTM C241/ ≤ 5.0. This can be ignored when using stones
C 1353 test for abrasion resistance as measured with abrasion resistances ≥20.0, since the
by abrasive hardness (Ha). There are three resultant wear will be very slight.
classes of usage for stone flooring:
2.2 Physical Property Values. Final
2.1.1 Light Traffic class is reserved for design should always be based on specific
residential use where there is relatively little property values of the stone to be used. These
traffic and/or shoes are not always worn. Stone values may be obtained from the Stone
must have a minimum Ha of 6.0. Supplier. When reliable physical property data
is not available from the supplier, re-testing of
2.1.2 Moderate Traffic class is reserved for the stone should be considered.
residential entranceways and small commercial
installations. Foot traffic is less than 50 2.3 Hollow Sound. Because of the weight
persons/minute. Stones must have a minimum and consequent difficulties in handling large-
Ha of 7.0 sized pavers, it is impossible to avoid an
occasional “hollow” sound found in some stone
2.1.3 Heavy Traffic class is reserved for units after installation.
commercial installations (banks, shopping
malls, train or bus stations, etc). Foot traffic is 2.3.1 Reasons for hollow sounds
over 50 persons/minute. Minimum Ha is 10.0 include:
for general areas, increasing to 12.0 for
stairways, elevator halls, and other 2.3.1.1 A hollow sound may indicate that
concentration areas. Exterior paving should insufficient bonding of the paver exists,
always have a minimum Ha of 12.0. although it is not necessarily a reliable test.

 2016 Marble Institute of America Horizontal Surfaces/General Notes • Page 14-1

Other influences can cause a hollow sound 2.4.2 IN NO CASE SHOULD NATURAL
from a properly bonded paver. STONE BE INSTALLED WITH TIGHT
JOINTS
2.3.1.2 Hollow sounds may be acoustical
effects rather than bonding problems. 2.4.3 Where vertical surfaces meet horizontal
paving, the joint should be filled with an
2.3.1.3 Air may be entrapped in either the elastomeric sealant in lieu of grout. These
setting bed or slab, causing one part of the floor joints should be at least 3/8" in width, and
to sound differently than another. continue through the stone assembly, all the
way down to the substrate or backing
2.3.1.4 Separation or crack-isolation (membranes may remain continuous). For
membranes installed between a slab and the joint depths greater than 3/8”, backer rod is
setting bed may alter the sound report. required. It is recommended that the
horizontal surface go under the vertical
2.3.1.5 The elevation or composition of the surface.
subsurface may be irregular, causing one part
of the floor to sound differently than another. 2.4.4 Movement Joints are also required in
fields of paving. Reference ANSI A108.01
2.4 Width of Joints between Stones. section 3.7 and ANSI A108.02 section 4.4 for
Joints between stones should be of sufficient guidance on movement joint location.
width to ensure that the grout being used can
be placed at the bottom face of the stone and 2.4.5 Movement Joints: In addition to field
properly compacted within the joint. and abutment to vertical surface requirements
for movement joints in stone work, any
2.4.1 Typical joint widths are: expansion or construction joints in the
substrate will need to carry completely
2.4.1.1 Exterior Stone Pavement through the stone installation assembly.
Installation: Minimum ¼", preferably 3/8".
Joints of ½” or larger are frequently required 2.4.6 Wash and dry backs and edges of all
for large unit size installation. pavers prior to installation.

2.4.1.2 Interior Stone Flooring Installation: 3.0 MINIMUM THICKNESS

Minimum 1/16”, preferably 1/8”. Joints of
¼” or larger are frequently required for large 3.1 Suggested minimum thicknesses for
unit size installation. stone walking surfaces:

2.4.1.3 Joints of ½” to 1” are frequently 3.2 Exterior Stone Pavers, Pedestrian

required for installing stones with split, or Traffic: 1¼".
“snapped” edges.
3.3 Exterior Stone Pavers, Vehicular
2.4.1.4 Stone units with “cleft” or other non- Traffic: Is best determined by engineering
planar surface finishes generally require larger analysis, but is generally 3” or thicker.
joints to minimize perceived lippage. Joint
widths of ¾” or 1” are not uncommon in these 3.4 Interior Residential Stone Flooring:
cases. 3/8”.

2.4.1.5 Joints of stone with an arris or 3.5 Interior Commercial Flooring, light
chamfer will appear wider than its actual duty: 3/8”.
dimension when filled.

Page 14-2 • Horizontal Surfaces/General Notes  2016 Marble Institute of America

3.6 Interior Commercial Flooring, Heavy sudden reduction in a floor’s static coefficient
Duty/High Traffic: ¾”, or 1¼” pending stone of friction. Aftermarket products are available
variety selection. for application on natural stones to increase
available friction if required. Such products
3.7 Note: Large stone unit sizes, specific must be applied and maintained according to
loading/traffic requirements may dictate the manufacturer’s recommendations.
use of greater thicknesses than those listed
above.
6.0 MEMBRANES
The use of membranes to improve system
4.0 LIPPAGE performance is common in the design of stone
Tolerances for allowable lippage can be found walking surface installations.
in Chapter 22 on Tolerances.
6.1 Always comply with the membrane
4.1 Allowable lippage is an installation manufacturer’s written instructions regarding
tolerance, and is additive to the inherent the applicability and installation of the
warpage of the stone unit. membrane product.

4.2 This lippage will not be attainable in 6.2 Common types of membranes and their
flamed, cleft, or otherwise textured finishes. intended contribution to the system
In those installations, joint width should be performance are discussed below:
increased to limit perceived lippage, and in
some cases joints as wide as ¾” may be 6.2.1 Cleavage Membranes. Cleavage
required. membranes are used in thick-bed installations
below a reinforced mortar bed to intentionally
4.3 This degree of accuracy may not be prevent the bond between the stone setting
achievable with extremely large format stone system and the substrate slab, allowing
pavers, in which case larger than typical joint independent movement (free floating) of the
widths are recommended to minimize stone and setting system. Cleavage membranes
perceived lippage. can be either sheet applied or liquid applied.

6.2.2 Crack Isolation Membranes. Crack

5.0 Slips and falls may be caused by Isolation membranes are used to isolate the
inadequate available friction or due to a sudden stone from minor in-pane cracking of the
change in available friction. For example, a substrate surface in thin-set applications.
spilled beverage or other contaminant may Crack Isolation membranes can be sheet
reduce available friction in a given area. applied, trowel applied, or liquid applied and
Because of this, the maintenance of a floor is an must meet ANSI A118.12.
important factor in its ability to provide a safe
walking surface. Local building codes normally 6.2.3 Uncoupling Membranes.
take precedence over other regulatory Uncoupling membranes are sheet applied, and
agencies. Natural stone used for paving geometrically configured to provide a small
provides an adequate available static coefficient airspace which accommodates lateral flexibility
of friction for human ambulation when between the tile and the substrate, reducing the
supplied with an appropriate finish and transfer of stresses to the thin-set stone
properly maintained. Proper maintenance installation system.
includes prompt cleanup of spills and
correcting other conditions that can cause a

 2016 Marble Institute of America Horizontal Surfaces/General Notes • Page 14-3

6.2.4 Waterproof Membranes. 8.0 GEOGRAPHIC METHODS
Waterproof membranes are used to prevent Some installation methods and materials are
the migration of liquid water. These not recognized and may not be suitable in some
membranes can be sheet applied, sheet metal, geographic areas because of local trade
or liquid applied. In many cases these practices, building codes, climatic conditions,
membranes are installed by other trades and or construction methods. Therefore, while
must meet ANSI A118.10. every effort has been made to produce accurate
guidelines, they should be used only with the
independent approval of technically qualified
7.0 TECHNICAL DATA persons.
During construction, the General Contractor
7.1 Each stone variety used for exterior
shall protect all stone from staining and
stone paving should conform to the applicable
damage.
ASTM standard specification and the physical
requirements contained therein. The
specification for each stone type follows:

7.1.1 Granite: ASTM C615, Standard

Specification for Granite Dimension Stone

7.1.2 Limestone: ASTM C568, Standard

Specification for Limestone Dimension Stone

7.1.3 Marble: ASTM C503, Standard

Specification for Marble Dimension Stone

7.1.3.1 Soundness Classification of “A” or

“B” is recommended; although some marbles
with lesser soundness can be considered if
waxing, sticking, filling, cementing, and
reinforcing are properly done.

7.1.4 Quartz-Based Stone: ASTM C616,

Standard Specification for Quartz-Based
Dimension Stone

7.1.5 Serpentine: ASTM C1526, Standard

Specification for Serpentine Dimension Stone

7.1.6 Slate: ASTM C629, Standard

Specification for Slate Dimension Stone

7.1.7 Soapstone: No ASTM Standard exists

at this time

7.1.8 Travertine: ASTM C1527, Standard

Specification for Travertine Dimension Stone

Page 14-4 • Horizontal Surfaces/General Notes  2016 Marble Institute of America

EXTERIOR PAVING 2.0 INSTALLATION
SYSTEMS 2.1 Mortar Bed Bonded to Concrete
Subsurface
1.0 PRODUCT DESCRIPTION
2.1.1 Preparatory Work. Concrete slabs
1.1 Basic Use. Exterior paving for plazas, to receive bonded mortar beds, shall fulfill the
promenades, and similar applications. following requirements:

1.2 Fabrication. Stone paving units are 2.1.2 Slope as required shall occur in the
precut and prefinished to dimensions specified slab so as to maintain an even depth or
on shop drawings, and are delivered to the job thickness of the mortar bed.
site ready to install.
2.1.3 Concrete Slab shall have a textured
1.3 Abrasion Resistance. See Section in surface similar to a fine broom finish and shall
Introduction. be free of curing compounds or any other
foreign materials that would inhibit an
1.4 Finishes. Abrasive, natural cleft, adequate bond of the mortar bed to the slab.
thermal, and rough sawn finishes are
recommended for exterior paving. 2.1.4 Concrete Slabs that require
additional work to achieve these requirements
1.5 Colors. Any of the commercially such as grinding, feathering, patching or
available varieties are suitable. scarifying are considered as non-compliant
with Industry Standards for stonework until
1.6 Sizes. Size and thickness should be remedial work has been completed by others.
based on:
2.1.5 Method. Stone paving should be
1.6.1 Flexural Strength (Ref: ASTM C880) of installed in a full mortar bed consisting of one
the stone part portland cement and from four to five
parts sand. Minimum thickness of a mortar bed
1.6.2 The unsupported span or anticipated
is 1¼". The recommended thickness is 2". A
deformation of the bedding system.
bond coat of portland cement paste or other
1.6.3 The anticipated load. approved material (slurry) is recommended.

1.6.4 Standard thicknesses of 1¼", 15/8”, and 2.1.6 Joints. The joints may be pointed
2" or greater may be required. with suitable mortar or grout, or left entirely
open to receive a resilient filler strip and
1.7 Movement Joints. All stone paving approved sealant.
systems shall include adequate movement
joints. Refer to ANSI 108.1 and TCNA EJ 171 2.1.7 Reinforcing. Reinforcing of the
for movement joint location and design. mortar bed is recommended for beds of 2”
depth or greater and shall be specified by the
1.8 Traffic after Installation. After the design professional. See TCNA F121 and
stone paving has been installed, the General NOTE for exterior uses.
Contractor must keep all traffic off the floors
for at least 48 hours. No rolling or heavy 2.2 Mortar bed separated from
(greater than pedestrian) traffic should be concrete slab. This method is used where
permitted on newly installed stone surfaces for the concrete slab may be problematic such as
at least two weeks after the floor has been anticipated differential movement between the
grouted or caulked. slab and the stone assembly. Other factors

 2016 Marble Institute of America Horizontal Surfaces/Exterior Stone Paving • Page 14-5
which favor selection of this installation thickness, span, flexural strength, and
method include: appropriate safety factors must be considered
in the design.
2.2.1 Cracks in the slab that may transfer
through a bonded system. 2.3.4 Open Joints. The joints in this system
are left open, allowing water to flow below the
2.2.2 Contamination of the slab that may be stone units to be collected by the drainage
impractical to remove. system.
2.2.3 Capillary moisture issues exist. 2.3.5 Advantages of this system include the
elimination of the requirement to slope the
2.2.4 Where cold or control joints in slab stone surface to a drain, since the drainage is
do not align with stone grid modules. accomplished below the pedestrian deck, and
the ease of removal and replacement of the
2.2.5 Where an unbondable membrane
pavers to facilitate servicing of the drainage
exists.
system below.
2.2.6 In these situations, the slab will require
2.4 Sand Bed Method
remedial treatment commensurate with the
severity of the problem. These options usually 2.4.1 Preparatory Work. Excavate
involve a membrane of some type and as such unsuitable, unstable, or unconsolidated
the mortar bed cannot be bonded to the subgrade material and compact the area that
substrate. As with the bonded mortar bed has been cleared. Fill and level with densely
systems, slope and tolerance of the slab shall be graded crushed stone aggregate suitable for
such as to maintain an even thickness of the subbase material, or as otherwise directed by
bed. Movement joint requirements will also Specifying Authority.
remain the same; however, the membrane may
remain continuous. 2.4.2 Method. Place bedding course of
sharp, normal weight limestone screening or
2.2.7 The mortar bed must be concrete sand to a depth of approximately 1½"
reinforced in any unbonded installation leveled to grade. Compact bedding course
system as specified by the design professional. parallel to finish grade and tamp.
2.3 Pedestal Supported Systems 2.4.3 Stone pavers shall be laid upon the
bedding course in successive courses. Every
2.3.1 Preparatory Work. Adequate slope
course of pavers shall be laid true and even and
for surface drainage must be provided in rough
brought to grade by the use of wood mallets or
concrete slab. Before being installed, all stone
similar tools, and shall be laid parallel to the
must be clean and free of foreign matter of any
base line. After the pavers are laid, the surface
kind.
shall be swept and inspected. Cover surface
2.3.2 Method. Stone slabs (pavers) shall be with a wood board approximately 3" thick, 12"
set on bricks, plastic pods, or mortar spots of wide, and 6' long, and tamp with an approved
one part portland cement and from three to tamper. Do all tamping immediately after
five parts sand, at or near the corners with the laying pavers and do not allow tamper to come
joints left open for drainage (see illustration at in contact with pavers. Broom sand into joints,
the close of this section). tamping sand in joints to ensure full bedding
around perimeter of stone.
2.3.3 Flexural Strength. In a pedestal
supported pavement system, the stone unit is a
structural member that carries the live and
dead loads back to the pedestals. Paver
Page 14-6 • Horizontal Surfaces/Exterior Stone Paving  2016 Marble Institute of America
INTERIOR STONE 2.5 Setting Bed. White Portland cement
with low alkali content is recommended for
FLOORING SYSTEMS light colored stone.

1.0 INTRODUCTION 2.6 Bond Mortar. White bond mortar is

recommended for light colored stone.
1.1 Installation Methods. Interior stone
flooring can be installed by several methods. 2.7 Hollow Sound. Refer to the section in
Consideration should be given to the various introduction portion of this chapter.
features of each method in making a selection
for a specific installation. (See Data Sheet 2.8 Traffic after Installation. After the
Installation section and illustrations of stone flooring has been installed, the General
installation examples at the close of this Contractor must keep all traffic off the floors
section). for at least 48 hours. No rolling or heavy
(greater than pedestrian) traffic should be
1.2 Abrasion Resistance. See permitted on newly installed stone flooring
Introduction Section. (Note: abrasion surfaces for at least two weeks after the floor
resistance does not measure values for has been grouted.
coefficient of friction or slip resistance.)
2.9 Sealing. Reference Maintenance and
Restoration Section of the DSDM for MIA
2.0 RELATED COMPONENTS position on sealers.

2.1 TCNA Details. Because natural stone 2.10 For additional information, refer
tiles can be installed in certain thin-bed setting to Chapter 13, INSTALLATION - GENERAL
systems in the same manner as ceramic tiles, INFORMATION.
the current “Handbook for Ceramic Tile
Installation” by the Tile Council of North 2.11 Geographic Methods. Some
America may be referred to for details. A list installation methods and materials are not
of details from this manual endorsed by the recognized and may not be suitable in some
MIA is included in Chapter 13 of this manual. geographical areas because of local trade
practices, building codes, climatic conditions,
2.2 Stone Abuts Softer Floor Material. or construction methods. Therefore, while
Where stone abuts softer flooring materials, a every effort has been made to produce accurate
stone threshold or metal edge protection strip guidelines, they should be used only with the
may be used. This will help prevent edge independent approval of technically qualified
chipping caused by impact. persons.

2.3 Grout. Sanded or unsanded grout, or

nonstaining sealant, can be used as joint filler. 3.0 PRODUCT DESCRIPTION
If sanded grout is used, mask the face of the
stone tile before filling the joints to avoid 3.1 Basic Use. As interior flooring for
scratching of the stone surface. commercial, institutional, and residential use.

2.4 Stones Sensitive to Moisture and 3.2 Abrasive Hardness. Reference

Alkalinity. Stone suppliers shall identify Introduction Section
stones that are adversely affected by moisture
and alkalinity. 3.3 Fabrication. Stone flooring units are
precut and prefinished to dimensions specified
on shop drawings, and delivered to the job site

 2016 Marble Institute of America Horizontal Surfaces/Interior Stone Flooring • Page 14-7
ready to install. Alternatively, stone flooring Testing and certification of compliance is the
units may be field cut or field modified at the responsibility of the specifying authority.
installation site. 4.1.3 Wash and dry backs and edges of
pavers or tiles prior to installation.
3.4 Finishes. Polished, honed, abrasive,
thermal, sanded, and natural cleft. 4.1.4 A mortar bed consisting of one part
portland cement to five parts sand is laid over
3.5 Colors. Most of the commercially the concrete subfloor to a nominal thickness of
available varieties are suitable. 1¼". Stone buttered uniformly with a cement
paste bond coat are laid over the mortar bed
and tamped into a true and level plane. Joints
4.0 INSTALLATION METHODS are grouted with a portland cement based
Interior stone flooring is installed by one of the grout or other approved material. (See Detail
following methods. at the close of this section).

4.1 Mortar Bed Bonded to Concrete 4.2 Mortar Bed Separated From
Subfloor This method is used where the Concrete Subfloor. This method is used
concrete sub-floor is not subject to excessive where the concrete slab may be problematic
movement or deflection (Recommended for such as anticipated differential movement
installation of larger pieces [slabs]). between the slab and the stone assembly.
Other factors that would favor the selection of
4.1.1 Concrete to receive bonded mortar this installation system include:
beds or direct bond of stone shall fulfill the
4.2.1 Cracks in the slab that may transfer
following requirements:
through a bonded system.
4.1.1.1 Slope if required, shall occur in the 4.2.2 Contamination of the slab that may be
concrete substrate so as to maintain an even impractical to remove.
depth or thickness of the mortar bed and/or
bond mortar. 4.2.3 Capillary moisture issues exist.

4.1.1.2 Concrete shall have a textured surface 4.2.4 Where cold or control joints in slab do
similar to a fine broom finish and shall be free not align with stone grid modules.
of curing of curing compounds or any other
foreign materials that would inhibit an 4.2.5 Where an unbondable membrane
adequate bond of the mortar bed or bond exists.
mortar to the concrete.
4.2.6 In these situations, the slab will require
4.1.1.3 Undersides and edges of concrete slabs remedial treatment commensurate with the
on grade shall have a suitable vapor barrier so severity of the problem. These options usually
as to prevent moisture intrusion into concrete. involve a membrane of some type and as such
the mortar bed cannot be bonded to the
4.1.1.4 Concrete that requires additional substrate. The requirement for unbonded
work to achieve these requirements such as mortar beds is that they be reinforced as
grinding, feathering, patching or scarifying are specified by the design professional; usually
considered as non- compliant with Industry with wire at the approximate center of the bed.
Standards for stonework until remedial work is As with the bonded mortar bed systems, slope
completed. and tolerance of the slab shall be such as to
maintain an even thickness of the bed.
4.1.2 Limits of moisture vapor transmission Movement joint requirements will also remain
shall be established by the stone supplier.
Page 14-8 • Horizontal Surfaces/Interior Stone Flooring  2016 Marble Institute of America
the same; however, the membrane may remain Joints are later grouted with a portland cement
continuous. based grout or other approved material.

4.3 Mortar Bed Separated From 4.5 Thin-Bed Portland Cement

Wood Subfloor. This method is used where Mortar Over Concrete Substrate
subfloor is subject to movement and
deflection. 4.5.1 This method is used when space for full
mortar bed is not possible. Concrete subfloor
4.3.1 Mortar bed floats over subfloor and should not be subject to excessive movement
minimizes possibility of stone cracking from or excessive deflection. Subfloor must be level
structural movement. An isolation membrane with maximum variation of ¼" in 10'-0".
is laid over the sub-floor. A mortar bed Mortar bed is laid using a notched trowel over
consisting of one part portland cement to four subfloor to a thickness of not greater than
to five parts sand with reinforcement specified 3/32". Apply mortar with flat side of trowel
by the design professional. Stone tiles are laid over an area that can be covered with tile while
over the mortar bed and tamped into proper mortar remains plastic. Within ten minutes
plane. Joints are later grouted with a portland and using a notched trowel sized to facilitate
cement based grout or other approved the proper coverage, comb mortar to obtain an
material. (See Detail D-3 at the close of this even setting bed without scraping the backing
section). material Key the mortar into the substrate with
the flat side of the trowel. Back butter the stone
4.4 Thin Bed Over Plywood Subfloor to ensure 95% contact with no voids exceeding
2 in² and no voids within 2” of tile corners on
4.4.1 This method should be used only in 3/8" tile. Back butter the stone tiles to ensure
residential construction. The subfloor must be 80% contact with no voids exceeding 4 in² and
adequately designed to carry loads without no voids within 2” of tile corners on ¾" or
excessive deflection. Subfloor must be level thicker material. All corners and edges of stone
with a maximum variation of 1/8" in 10'-0", tiles must always be fully supported and
and a deflection not exceeding L/720. Cross- contact shall always be 95% in water-
bridging or other reinforcement shall be used susceptible conditions. Joints are later grouted
to limit differential deflection between with a portland cement based grout or other
adjacent framing members. Comply with all approved material. (See Detail at the close of
Manufacturers’ written installation this section).
instructions. Apply mortar with flat side of
trowel over an area that can be covered with 4.6 Thin-Bed Mortar Over
tile while mortar remains plastic. Within ten Cementitious Backer Units
minutes and using a notched trowel sized to
facilitate the proper coverage, comb mortar to 4.6.1 This method should be used only in
obtain an even setting bed without scraping the residential construction and per
backing material. Key the mortar into the manufacturers’ instructions. The subfloor
substrate with the flat side of the trowel. Back must be adequately designed to carry loads
butter the stone tiles to ensure 95% contact without excessive deflection. The
with no voids exceeding 2 in² and no voids cementitious backer unit is considered to be a
within 2” of tile corners on 3/8" tile. Back bonding layer only, and provides negligible
butter the stone tiles to ensure 80% contact structural contribution to the flooring system.
with no voids exceeding 4 in² and no voids Subfloor must be level with a maximum
within 2” of tile corners on ¾" or thicker variation of 1/16" in 3'-0", and a deflection not
material. All corners and edges of stone tiles exceeding L/720. Cross-bridging or other
must be fully supported and contact shall reinforcement shall be used to limit differential
always be 95% in water-susceptible conditions. deflection between adjacent framing members.
Apply mortar with flat side of trowel over an
 2016 Marble Institute of America Horizontal Surfaces/Interior Stone Flooring • Page 14-9
area that can be covered with tile while mortar 6.0 PLYWOOD SUBFLOORS
remains plastic. Within ten minutes and using
a notched trowel sized to facilitate the proper 5.3 Refer to APA form No. E30 for
coverage, comb mortar to obtain an even plywood installation methods.
setting bed without scraping the backing
material. Key the mortar into the substrate 5.3.1 Plywood subfloors, including tongue-
with the flat side of the trowel. Back butter the and-groove plywood, must be installed with a
stone tiles to ensure 95% contact with no voids gap between the sheets to allow for expansion.
exceeding 2 in² and no voids within 2” of tile Stagger all seams. All subfloor seams should
corners on 3/8" tile. Back butter the stone tiles occur over framing, with underlayment seams
to ensure 80% contact with no voids exceeding occurring approximately 25% into the span
4 in² and no voids within 2” of tile corners on between framing members. Plywood should
¾" or thicker material. All corners and edges have the strength axis running perpendicular to
of stone tiles must be fully supported and the joist.
contact shall always be 95% in water-
susceptible conditions. Joints are later grouted 5.3.2 Plywood shall be APA underlayment,
with a portland cement based grout or other C-C plugged or plugged crossband grade.
approved material.
5.3.3 Inner surfaces must be clean. Remove
all sawdust and dirt before applying adhesive.
5.0 HEATED FLOOR SYSTEMS 5.3.4 Use a construction adhesive, applying a
1/8" bead at 2" intervals. Apply adhesive in
5.1 In frame construction, the plywood accordance with manufacturer’s written
portion of the substrate must be a minimum of directions.
1½" exterior glue plywood. Leave a gap
between the plywood sheets for expansion. 5.3.5 Allow adhesive to cure per
Install a cleavage membrane over the plywood. manufacturer’s recommendations before
beginning stone installation.
5.2 Frame and Mortar Bed. Heated
floor systems are generally proprietary in 5.3.6 Place screws 6" on center in both
nature, and the manufacturer’s installation directions.
guidelines shall be closely followed. Consider
using a heat deflector on top of the membrane. 5.3.7 Align strength axis of both subfloor and
The Heating Contractor should install the underlayment layers.
heating system per Manufacturer’s
recommendation. Fill cavity with a wire or 5.3.8 Always apply a double layer
portland mix so that the mortar bed covers subfloor/underlayment, regardless of joist
pipes and is at least ¾" over the top of heating spacing.
pipes, with a minimum bed thickness of 2½".
Allow to cure for at least 30 days. This mortar 5.3.9 Always use a crack suppression
bed thickness is necessary to dissipate heat to membrane in frame construction.
avoid damaging the stone by uneven heating.
Follow applicable Data Sheet Installation
methods listed previously, but first install a
crack-suppression or uncloupling membrane
according to Manufacturer’s recommendation.

Page 14-10 • Horizontal Surfaces/Interior Stone Flooring  2016 Marble Institute of America
HORIZONTAL with a low alkali content is recommended for
limestone.
SURFACES –
STONE THRESHOLDS 2.6 Exposed edges may be eased,
rounded, arrised or beveled. If instructions are
1.0 INTRODUCTION not given as to type of edge required, Supplier
will furnish according to industry standards.
1.1 Installation Methods. Stone
2.7 For additional information, refer
thresholds can be installed by several methods.
to Chapter 13, INSTALLATION - GENERAL
Consideration should be given to the various
INFORMATION.
features of each method in making a selection
for a specific installation. (See Data Sheet
2.8 Geographic Methods. Some
Installation section and illustrations of
installation methods and materials are not
installation examples at the close of this
recognized and may not be suitable in some
section).
geographic areas because of local trade
practices, building codes, climatic conditions,
or construction methods. Therefore, while
2.0 DESIGN CRITERIA every effort has been made to produce accurate
guidelines, they should be used only with the
2.1 Thresholds. By acting as a transitional independent approval of technically qualified
piece between two different finished floor persons.
levels, thresholds permit the use of the
conventional, thick-bed mortar method in
rooms where it would not otherwise be
possible. They also can be used with thin-set 3.0 PRODUCT DESCRIPTION
methods.
3.1 Basic Use. Floor structural element
2.2 Abrasive Hardness. Care should be that lies below a door or other entranceway.
taken to ensure the abrasive hardness (Ha) of
the varieties selected is a minimum of 12.0 as 3.2 Limitations. Only varieties having a
measured by ASTM C241. These values may minimum abrasive hardness (Ha) of 12.0, as
be obtained from the Stone Supplier. measured by ASTM C241, are recommended.

2.3 Stone Abuts Softer Floor Material. 3.3 Fabrication. Stone thresholds are
Where stone abuts softer flooring materials, precut and prefinished to dimensions specified
stone thresholds or metal edge protection on shop drawings, and delivered to the job site
profiles may be used. This will help prevent ready to install.
chipping caused by impact.
3.4 Finishes. Polished and honed.
2.4 Traffic after Installation. After the
stone thresholds have been installed, the 3.5 Colors. Most of the commercially
General Contractor must keep all traffic off the available varieties are suitable.
thresholds for at least 48 hours. No heavy
traffic should be permitted on newly installed 3.6 Sizes. Thicknesses of ½", ¾", and 1¼",
stone flooring surfaces for at least two weeks. or as specified.

2.5 White portland cement is

recommended as a setting bed for light-colored
granite and marble. White portland cement

 2016 Marble Institute of America Horizontal Surfaces/Stone Thresholds • Page 14-11

4.0 TECHNICAL DATA 5.3 General Precaution. During
construction, the General Contractor shall
4.1 Each stone variety used for thresholds protect all stone from staining or damage.
should conform to the applicable ASTM
standard specification and the physical
requirements contained therein. The
specification for each stone type follows:

4.1.1 Granite: ASTM C615, Standard

Specification for Granite Dimension Stone

4.1.2 Limestone: ASTM C568, Standard

Specification for Limestone Dimension Stone

4.1.3 Marble: ASTM C503, Standard

Specification for Marble Dimension Stone

4.1.4 Quartz-based Stone: ASTM C616,

Standard Specification for Quartz-based
Dimension Stone

4.1.5 Slate: ASTM C629, Standard

Specification for Slate Dimension Stone

4.1.6 Serpentine: ASTM C1526, Standard

Specification for Serpentine Dimension Stone

4.1.7 Soapstone: No ASTM Standard exists

at this time

4.1.8 Travertine: ASTM C1527, Standard

Specification for Travertine Dimension Stone

5.0 INSTALLATION

5.1 Methods. Stone thresholds may be

installed using a cement mortar bed, epoxy
mortar, or any of the thin-set mortar methods.
(See detail illustrations at the close of this
section).

5.2 100% coverage of mortar bed material

between threshold and subfloor is
recommended.

Page 14-12 • Horizontal Surfaces/Stone Thresholds  2016 Marble Institute of America

NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

HORIZONTAL permitted on newly installed treads for at least
two weeks.
SURFACES –
STONE STAIR TREADS 2.5 Thin stone (½" and under) treads and
risers may be installed using a thin-set portland
1.0 INTRODUCTION cement mortar bed over clean and level
concrete subtreads or double layers of ¾"
1.1 Installation Methods. Stone stair plywood installed in opposite directions with
treads can be installed by several methods, each 1/8" gaps between sheets. These types of
dependent upon the design detail. applications will not withstand high impact or
Consideration should be given to the various wheel loads. No overhang is permitted when
features of each method in making a selection stones of this thickness are used.
for a specific installation. (See Data Sheet
Installation section and illustrations of 2.6 White portland cement is
installation examples at the close of this recommended as a setting bed for light-colored
section). granite and marble. White portland cement
with a low alkali content is recommended for
limestone.
2.0 DESIGN CRITERIA 2.7 For additional information, refer
to Chapter 13, INSTALLATION - GENERAL
2.1 Final design should always be based on INFORMATION.
physical properties of the stone to be used. If
the open-tread detail is planned utilizing the 2.8 Geographic Methods. Some
stone tread as a structural member spanning installation methods and materials are not
the stringers, the thickness should be recognized and may not be suitable in some
developed by an Engineer based on the geographical areas because of local trade
strength properties furnished by the Stone practices, building codes, climatic conditions,
Supplier. or construction methods. Therefore, while
every effort has been made to produce accurate
2.2 Slip Resistance. Slip resistant strips or guidelines, local building codes should be
filled grooves are recommended in heavy- consulted for compliance.
traffic areas. These can be specified as shop
fabricated or field installed per applicable code
or building requirements.
3.0 PRODUCT DESCRIPTION
2.3 Deflection. The backup for stone steps
must be of limited (<L/720) deflection for 3.1 Basic Use. Horizontal top part of a step
installation of thin (1¼" or less) treads. If there in a staircase.
is greater deflection, the thickness of the tread
is determined by calculating the load and 3.2 Limitations. Only varieties having a
ensuring that the flexural strength (ASTM minimum abrasive hardness (Ha) of 12.0 or
C880) of the stone is sufficient to resist the more, as measured by ASTM C241, are
load, including a safety factor. In any event, the recommended.
minimum recommended thickness is 1¼" for
treads and ¾" for risers. 3.3 Finishes. Honed, polished, abrasive,
thermal, and natural cleft for interior uses;
2.4 Traffic after Installation. After the rough, textured, abrasive, thermal, honed, and
stone treads have been installed, the General natural cleft for exterior uses.
Contractor must keep all traffic off the treads
for at least 48 hours. No heavy traffic should be
 2016 Marble Institute of America Horizontal Surfaces/Stone Stair Treads • Page 14-13
3.4 Colors. Most of the commercially set cement mortar bed, over a subtread, or
available varieties. supported by stringers. (See detail illustrations
at the close of this section).
3.5 Sizes. Tread thicknesses of ¾", 1¼", 5.1.1 100% coverage of mortar bed material
and 1½" for interior uses. Thicknesses of 1½", between tread and subtread is desirable.
2" and cubic (greater than 2") for exterior.
Risers may be ¾" or 1¼" thick. 5.1.2 Risers ¾" or thicker must be anchored
with wire or stainless steel strap anchors. If
risers thinner than ¾" are used, they may be
4.0 TECHNICAL DATA installed using the thin-bed portland cement
mortar method.
4.1 Each stone variety used for stone stair
treads should conform to the applicable ASTM 5.2 General Precaution. During
standard specification and the physical construction, the General Contractor shall
requirements contained therein. The protect all stone from staining or damage.
specification for each stone type follows:

4.1.1 Granite: ASTM C615, Standard

Specification for Granite Dimension Stone

4.1.2 Limestone: ASTM C568, Standard

Specification for Limestone Dimension Stone

4.1.3 Marble: ASTM C503, Standard

Specification for Marble Dimension Stone
(Exterior)

4.1.4 Quartz-based Stone: ASTM C616,

Standard Specification for Quartz-based
Dimension Stone

4.1.5 Slate: ASTM C629, Standard

Specification for Slate Dimension Stone

4.1.6 Serpentine: ASTM C1526, Standard

Specification for Serpentine Dimension Stone

4.1.7 Soapstone: No ASTM Standard exists

at this time

4.1.8 Travertine: ASTM C1527, Standard

Specification for Travertine Dimension Stone

5.0 INSTALLATION

5.1 Methods. Stone stair treads may be

installed in a cement mortar bed, or in a thin-

Page 14-14 • Horizontal Surfaces/Stone Stair Treads  2016 Marble Institute of America
NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

VERTICAL SURFACES - 1.2.1 Restraint and relief are achieved by
using a combination of lateral ties (straps, split-
INSTALLATION NOTES tail anchors, welded tees, or other positively
engaged mechanical anchorage approved by a
qualified design professional) and gravity relief
1.0 VERTICAL SURFACES supports.
INSTALLATION SYSTEMS
Vertical Stone Surfaces are installed with a 1.2.2 Each stone panel is restrained by
variety of conventional and proprietary mechanical anchorage attached to the back up
systems. A brief discussion of the more wall substrate (building structure, masonry
common types is below: backup, stud framing assembly, miscellaneous
steel, and etc.). The stone panels and
1.1 Independently Supported Veneer associated anchorage are designed to
accommodate lateral loads only (wind and
1.1.1 Each stone panel is independently seismic forces) as required by governing codes
supported (relieved and restrained) by and/or project specifications. These loads are
mechanical anchorage attached to the back up transferred directly to the back up wall
wall substrate (building structure, masonry substrate through the stone anchorage.
backup, stud framing assembly, miscellaneous Relieving supports (i.e., continuous angles or
steel and etc.). clips) are designed to accommodate the
cumulative vertical load of the stone veneer
1.1.2 The stone panels and associated units “stacked” between the relief support and
anchorage are designed to accommodate expansion or control joint above, typically a
vertical loads (stone unit self weight) and live load joint at a floor/slab line. Relief
lateral loads (wind and seismic forces) as supports are typically provided over all
required by governing codes and/or project openings and at each story height (or maximum
specifications. Each of these loads is transferred vertical spacing of 20'). Within a “stack”,
directly to the back up wall substrate through vertical loads are typically transferred from one
the stone anchorage. Joints between each stone stone to another using load-bearing shims or
are designed to accommodate thermal mortar. The joints are typically filled with a
expansion and differential movement between non-staining sealant or mortar adequate to
stone units, and therefore, must remain free of meet the performance requirements for the
shims, mortar, or any other rigid material that project.
would transfer load from one stone to another.
The joints are typically filled with a non- 1.2.3 Consideration of weeps and flashing is
staining sealant that possesses compressive and recommended when continuous relief angles
tensile capacities adequate to meet the are utilized.
performance requirements for the project. A
minimum joint width of 3/8" is recommended 1.3 Adhered Installation
for exterior stone veneer. Larger joints may be
required to accommodate specific project 1.3.1 Thin Stone. Adhered installation is to
demands. Note: This system can also be be used for thin stone only (¼" to ½"
installed as a rainscreen or open-joint façade thickness) of heights not exceeding 15’-0” (4.5
omitting joint sealant between stone veneer m).
units.
1.3.2 Units shall not exceed 36 inches (914
1.2 “Stacked” Veneer With Relieving mm) in the greatest dimension nor more than
Supports 720 square inches (0.46 m2) in total area and
shall not weigh more than 15 pounds per

 2016 Marble Institute of America Vertical Surfaces/General Notes • Page 15-1

square foot (73 kg/m2) unless approved by the 1.4 Other systems include a variety of
local governing officials and the engineer of prefabricated and proprietary systems
record. commonly known as:

1.3.3 Thin-Set Mortar [Thin Bed (ANSI 1.4.1 “Grid” systems, commonly composed
A118.1)]. See Chapter 13, section 3.1.2. of vertical and horizontal support framing of
varying corrosion-resistant materials, such as
1.3.4 Latex-Portland Cement Mortar aluminum, mild steel, cold-formed steel, or
[Thin Bed (ANSI A118.4)]. See Chapter 13, stainless steel. The framing is typically pre-
section 3.1.3. installed in the stone setting cavity to the
substrate or support wall. Stone supports are
1.3.5 Epoxy Mortar (ANSI A118.3). See typically integrated in the system design.
Chapter 13, section 3.1.4.
1.4.2 “Strut” systems are commonly
1.3.6 Limestone Setting Mortar. See composed of vertical support framing of
Chapter 13, section 3.1.5. varying corrosion-resistant materials such as
aluminum, mild steel, cold-formed steel or
1.3.7 Setting Bed. White portland cement stainless steel. The framing is typically pre-
with low alkali content is required for all light installed in the stone setting cavity to the
colored stone varieties. substrate or support wall. Non-integrated
stone supports are typically attached in a
1.3.8 Petroleum-based organic method similar to Independently Supported
adhesives should be avoided because they Veneer or “Stacked” Veneer with Relieving
may stain the stone. Supports.

1.3.9 Recommended substrate 1.4.3 Integrated Stone Curtain Wall.

materials are masonry and cementitious Stone veneer installed in glazing channels of
backer board. glazed curtain wall members, in similar
manner to metal spandrel panels or stone
1.3.10 Exterior Vertical Surfaces. When veneer installed in structurally glazed curtain
adhesive installation methods are used for walls, in a similar manner to glass.
exterior vertical surfaces, the stone shall be
back buttered to achieve, as close as practical, 1.4.4 Panelized dimension stone
100% adhesive contact between the stone and cladding, which may include independently
the backup. Remove freshly installed tiles supported veneer, “stacked” veneer with
periodically during installation to verify relieving supports, adhered veneer, or a
adhesion level. combination of these methods. This is also
known as a truss system.
1.3.11 When thin stone tiles are installed
on exterior vertical surfaces, they are fully 1.5 Consideration should be given to the
reliant upon the backup and substrate for various features of each system in making a
performance. Use of unstable backup materials selection for a specific installation. See detailed
should be avoided. illustrations of examples at the close of this
section.
1.3.12 Substrates to receive adhered
veneer using thin-set adhesive methods shall be 1.6 Venting of Exterior Stone Veneers
held to a tolerance of 1/8” variation in 10’-0”.
1.6.1 Existing Methods. The existing
methods of installing exterior thin stone veneer

Page 15-2 • Vertical Surfaces/General Notes  2016 Marble Institute of America

have evolved through the years. For the most 2.1.2 Anchor Placement. Under typical
part, the standards were developed when the conditions, standard practice provides for a
joints were filled with portland cement mortar minimum of 4 anchors per piece of stone up to
and the building interiors were not 12 sq ft of surface area, and 2 anchors for each
temperature- and humidity-controlled. additional 8 sq ft. Weight, size, shape, and type
of stone may dictate deviations from the
1.6.2 Additional Techniques. With foregoing. IBC currently prescribes minimum
today’s improved construction techniques, it is anchorage quantities for non-engineered “stone
possible to produce structures that are highly veneer” and “slab type veneer” based on the
resistant to natural weather conditions. Joints surface area of the stone panels. Due to varying
can be sealed with resilient sealants and the loads, stone properties, and anchor capacities,
building interior can be temperature- and this may not necessarily be adequate,
humidity-controlled. Venting of the cavity is particularly when public or occupant safety
recommended to prevent moisture problems. may be compromised. It is recommended that
It is recommended that a vapor barrier be exterior stone cladding systems be reviewed by
installed at the exterior face of the backup wall. an experienced stone cladding engineer to
The back face of the stone should not be sealed. verify anchor and panel capacities. In all cases,
anchorage shall be compliant with the project
1.6.3 Veneer Cavities. Solid grouting of specifications, requirements of the engineer of
stone veneer cavities that would permit passage record, and/or applicable codes.
of moisture through the wall from exterior to
interior, and interior to exterior, is 2.1.3 Anchor Types. Anchors shall be of
inadvisable. Windblown rain would be forced non-staining, corrosion resistant metals.
through the wall, and water vapor would move Stainless steel, aluminum, bronze, and brass
from exterior to interior and reverse, forced by wire and straps, and copper wire are preferred
the temperature and humidity differentials for their corrosion resistance. (See
from outside to inside. illustrations of typical anchors and accessories
at the close of this chapter). In exterior
1.7 Relieving Supports cladding systems, stainless steel (series 304) is
the most common. Copper is commonly
1.7.1.1 Relieving angles should be provided limited to interior applications.
over all openings and at each story height (or
maximum vertical spacing of 20'). Angles 2.1.3.1 Copper Wire Tie Anchorage is a
should have ¼" weep holes every 2'. When historically effective method of anchoring
stone liners are used, they are fastened by stone panels, but is to be used within the
stainless steel dowels and epoxy to the back of following limitations:
the finished stone facing and are supported on
these angles. Refer to local codes for variance. 2.1.3.1.1 Wire anchors are not generally
recommended for installations exceeding 15’-
0” vertically.
2.0 RELATED COMPONENTS
2.1.3.1.2 Stainless steel wire is recommended
2.1 Mechanical Anchors, Exterior in lieu of copper wire for exterior or wet area
and Interior interior applications. “Spot” material used in
conjunction with wire anchors in exterior or
2.1.1 Anchor Size. Anchor sizing is wet areas shall be of a portland cement based
dependent upon materials, codes, and physical compound. Setting plaster, moulding plaster,
conditions of the structure. Anchors should be or other gypsum based products are not
engineered separately for each. adequate products for this purpose.

 2016 Marble Institute of America Vertical Surfaces/General Notes • Page 15-3

2.1.3.1.3 When copper wire is used, it is 2.2 Shims. Shims shall be stainless steel or
common in some geographical regions to twist high-impact plastic or approved equal. Shim
the wire to stiffen the wire via metallurgical size shall distribute the loads to ensure that
work hardening. Excessive work hardening of point loading does not affect stones
the wire can lead to embitterment of the metal. performance.
Care must be taken to ensure that the physical
properties of the wire have been improved and 2.2.1 Where permanent setting pads are
not degraded by this process. required, 90 durometer neoprene or high-
impact plastic is recommended.
2.1.4 Thin Stone. Natural stone in
thicknesses of less than ¾” (20 mm) are not 2.2.2 Shims used in joints of “stacked” veneer
usually capable of receiving mechanical anchors systems remain in the joint permanently to
and can only be used with adhesive attachment. transfer load from course to course. Shims
may be used to temporarily maintain joint
2.1.5 Technical Information. Every width in other joint conditions but are to be
construction condition requires engineering removed prior to application of joint filler
based on specific factors for each project–panel material.
weight, wind and seismic loads, backup
material, stone compressive and flexural 2.3 Sealant: Silicone-based building
properties, etc. The most stringent building sealants that remain flexible with a modulus
code always takes precedence. Contact the capable of accommodating anticipated inter-
engineer or manufacturer of each anchoring panel movements are recommended for
system for its particular technical information vertical work. Verify the sealant is non-
and engineering formulas. staining to the specified stone material.

2.1.5.1 Grout. When using adhesion 2.4 Metal Studs. Metal studs placed
installation methods, grout joints shall be a behind stone wall installations to hold the wall
minimum of ¼" wide. Apply grout to full should be 16 gauge or heavier.
depth of stone. Avoid use of “designer grouts”
on exterior or in wet areas, as these grouts tend 2.4.1 Lateral channels are frequently required
to be soft and very absorbent. to facilitate attachment locations and also to
distribute loads over multiple studs.
2.1.5.1.1 Limestone and Light-Colored
Stones. Wherever limestone, or white and 2.4.2 Where studs exceed 8'-0" in height, it
light-colored marble or granite are to be may be necessary to relieve the weight at a
installed, it is important to use only white maximum of 8'-0" intervals.
portland cement, white thin-set mortar, or
white-colored adhesive to adhere the stone to 2.4.3 Walls and partitions constructed of
the backup, or for setting anchors. It is normal metal studs should be designed to maximum
for the setting spots to darken the stone at the deflection of L/720 for conditions utilizing
face. The dark coloring should disappear as the thick-set or thin-set mortar installation
setting material cures and excess moisture is methods.
ventilated from the cavity. (This process has
been known to take up to 8 months). Prior to 2.5 Joint Size. Typical joint widths are:
installing any stone the Setter is not
experienced with, the setting material should 2.5.1 Exterior Stone Cladding: Minimum ¼",
always be applied to a test scrap stone and preferably 3/8". Joints of ½” or larger are
allowed to cure thoroughly to make sure that frequently required for large unit size
the stone will not be permanently stained. installation.

Page 15-4 • Vertical Surfaces/General Notes  2016 Marble Institute of America

2.5.2 Interior Stone Cladding: Minimum
1/16”, preferably 1/8”. Joints of ¼” or larger
are frequently required for large unit size
installation.

2.5.3 IN NO CASE SHALL TIGHT or

“HAND-BUTTED” JOINTERY BE USED.

2.6 Lippage. Tolerances for allowable

lippage can be found in Chapter 22 on
Tolerances.

2.6.1 Allowable lippage is an installation

tolerance, and is additive to the inherent
warpage of the stone unit.

2.6.2 This lippage may not be attainable in

flamed, cleft, or otherwise textured finishes.
In those installations, joint width should be
increased to limit perceived lippage, and in
some cases joints as wide as ¾” may be
required.

2.6.3 This lippage may not be achievable in

extremely large format stone pavers, in which
case larger than typical joint widths are
recommended to minimize perceived lippage.

2.7 Exposed stone edges must be gauged

to the precise thickness specified.

2.8 Physical Property Values. Final

design should always be based on specific
physical property values obtained by ASTM
test methods for the stone and attachment
method systems to be used.

 2016 Marble Institute of America Vertical Surfaces/General Notes • Page 15-5

NOTES:

Page 15-6 • Vertical Surfaces/General Notes  2016 Marble Institute of America

EXTERIOR STONE 2.3 Gypsum Plaster. The use of gypsum
plaster (molding plaster) setting spots for
VENEER exterior stone is not acceptable practice.

1.0 INTRODUCTION 2.4 Shims shall be stainless steel or high-

impact plastic or approved equal. Shim size
1.1 Installation Methods. There are shall distribute the loads to ensure that point
several methods by which exterior stone loading does not affect stones performance.
cladding can be installed. Consideration
should be given to the various features of each 2.4.1 Where permanent setting pads are
method in making a selection for a particular required, 90 durometer neoprene or high-
installation. See detailed illustrations of impact plastic is recommended.
examples at the close of this section.
2.5 Insulation. Because heat is easily
1.2 For additional information, refer transmitted through stone when stone is part of
to Chapter 13 Installation – General a system assembly, insulation should be
Information. provided by other Contractors. Insulation
should never be placed directly against the
1.3 Geographic Methods. Some stone.
installation methods and materials are not
recognized and may not be suitable in some 2.6 Control and Expansion Joints. In
geographic areas because of local trade exterior stone walls, expansion joints may be
practices, building codes, climatic conditions, provided to reduce the damaging effect of
or construction methods. Therefore, while building and/or veneer movements due to
every effort has been made to produce accurate thermal expansion, structural live load
guidelines, they should be used only with the deflection, seismic displacement, and other
independent approval of technically qualified applicable movements based on project
persons. conditions and material properties. Because of
the many conditions and structural systems in
1.4 General Precautions. During which stone can be installed, the Specifying
construction, the General Contractor shall Authority or engineer of record shall show
protect all stone from staining and damage. locations and details of expansion joints on
project drawings and/or calculations.

2.0 RELATED COMPONENTS

3.0 HYSTERESIS
2.1 Anchorage Hardware: All anchors
in contact with exterior stone are to be non- 3.1 Hysteresis is a phenomenon that affects
corroding. certain “true” marbles. Unlike most stones,
which return to their original volume after
2.2 Joint Fillers. When using adhesion exposure to higher or lower temperatures,
installation methods, grout joints shall be a these marbles show small permanent increases
minimum of ¼" wide. Apply grout to full in volume after each thermal cycle. This can
depth of stone. Silicone-based building result in differential expansion within the
sealants that remain flexible with a modulus stone, which is more likely to be
capable of accommodating anticipated inter- accommodated or restrained in thick veneers
panel movements are recommended for than in thin ones. If it is not restrained, bowing
vertical work. Verify the sealant is non- of the marble panels ensues. Bowing also
staining to the specified stone material. stretches the face, which makes stones more
porous and increases their vulnerability to
 2016 Marble Institute of America Vertical Surfaces/Exterior Stone Veneer • Page 15-7
corrosion from acids in the atmosphere and 5.0 TECHNICAL DATA
deterioration from freezing and thawing
effects. If marbles with this tendency are 5.1 Each stone variety used for exterior
selected, research shall be performed to veneer should conform to the applicable ASTM
determine the minimum thickness needed to standard specification and the physical
overcome effects of hysteresis. requirements contained therein. The
specification for each stone type follows:

DATA SHEET 5.1.1 Granite: ASTM C615, Standard

Specification for Granite Dimension Stone
4.0 EXTERIOR STONE VENEER -
PRODUCT DESCRIPTION 5.1.2 Limestone: ASTM C568, Standard
Specification for Limestone Dimension Stone
4.1 Basic Use. Exterior cladding or facing
for structural elements. 5.1.3 Marble: ASTM C503, Standard
Specification for Marble Dimension Stone
4.1.1 Thickness Limitations for (Soundness Classifications A and B only)
Mechanically Attached Systems. As a
general rule, stone panel thickness should be a 5.1.4 Quartz-based Stone: ASTM C616,
minimum of 1¼". However, panel sizes and Standard Specification for Quartz-based
thicknesses may also be dictated by local codes, Dimension Stone
wind load requirements, areas of usage, and
material performance as determined by ASTM 5.1.5 Serpentine: ASTM C1526, Standard
standard specifications. Refer to ASTM C1528 Specification for Serpentine Dimension Stone
for recommendations of minimum stone
thickness. 5.1.6 Slate: ASTM C629, Standard
Specification for Slate Dimension Stone
4.1.2 Fabrication. Exterior veneer units are
precut and prefinished to dimensions specified 5.1.7 Soapstone: No ASTM Standard exists
on shop drawings and are typically delivered to at this time.
the job site ready to install.
5.1.8 Travertine: ASTM C1527, Standard
4.1.3 Finishes. Most commercially available Specification for Travertine Dimension Stone
stone thicknesses are suitable for exterior
veneer. Some stones, notably marbles, may
not retain a polished finish in exterior 6.0 ENGINEERING
environments.
6.1 A knowledgeable and experienced
4.1.4 Colors. Most of the commercially Installer must provide an engineered and
available varieties are suitable. fabricated system that will satisfy functional
and aesthetic requirements. However, deter-
4.1.5 Panel Sizes. Panel sizes are subject to mining which performance requirements and
the size and soundness of the block yielded by the criteria under each must be made by the
the quarry. Generally, panel dimensions of Specifying Authority in consultation with the
greater than 5’-0” (1.5 m) can create supply Structural Engineer.
and/or anchorage difficulties. The designer is
encouraged to verify obtainable dimensions
with the quarrier of the material prior to
finalizing the design.

Page 15-8 • Vertical Surfaces/Exterior Stone Veneer  2016 Marble Institute of America
7.0 GENERAL PRECAUTION:

7.1 During construction, the General

Contractor shall protect all stone from staining
and damage.

7.2 Caution is advised when using historical

test data for natural stones. It is preferable to
use data obtained from test specimens from
current quarry production that is
representative of the actual product being
supplied. Test data should be obtained from
certified testing agencies specializing in natural
stone testing.

 2016 Marble Institute of America Vertical Surfaces/Exterior Stone Veneer • Page 15-9
NOTES:

Page 15-10 • Vertical Surfaces/Exterior Stone Veneer  2016 Marble Institute of America
INTERIOR STONE WALL 2.2 Installation. Stone wall facing panels
may be installed either by conventionally set
CLADDING method using nonstaining anchors, dowels,
pins, cramps, wire, and mortar spots;
1.0 INTRODUCTION nonstaining adhesive in securing thin tile units
to interior vertical surfaces; or by one of the
1.1 Installation Methods. There are several mechanical methods.
several methods by which interior stone
cladding can be installed. Consideration 2.3 Physical Property Values. Final
should be given to the various features of each design should always be based on specific
method in making a selection for a particular physical property values of the stone. These
installation. See detailed illustrations of values are available from the Stone Supplier.
examples at the close of this section.

1.2 For additional information, refer 3.0 MECHANICAL SYSTEMS

to Chapter 13 Installation – General
Information. 3.1 Performance Criteria. The
Specifying Authority must determine the
1.3 Geographic Methods. Some performance criteria of the mechanical system
installation methods and materials are not to be employed.
recognized and may not be suitable in some
geographic areas because of local trade 3.2 Engineering. A knowledgeable and
practices, building codes, climatic conditions, experienced Installer must be engaged to
or construction methods. Therefore, while engineer and fabricate a system that will satisfy
every effort has been made to produce accurate the functional and aesthetic requirements of
guidelines, they should be used only with the the project.
independent approval of technically qualified
persons. 3.3 Anchorage systems must be securely
attached and located as shown on the approved
1.4 General Precautions. During shop drawings and shall be plumb and in true
construction, the General Contractor shall plane.
protect all stone from staining and damage.
3.4 Assembly/Installation Systems. A
number of proprietary assembly and
2.0 DESIGN CRITERIA installation systems are available.

2.1 Stone Size and Thickness. Most 3.5 Panel Installation. Stone panels must
dimension stones, as defined by ASTM C119, be installed to the mechanical system in the
are suitable for interior cladding. Stone panel prescribed manner, with vertical lines plumb
size and thickness are closely interrelated with and horizontal lines level.
the type of stone being installed and its
particular engineering qualities. Generally, 3.6 Conditions. In all conditions, the
consideration for greater stone thickness substrate must be installed sufficiently true and
should be made for larger-sized stones (over 12 level so that the stone panels or tiles may be
sq ft) set at higher elevations, and more fragile installed true and level and sufficiently rigid to
stones, with the exception of natural stone ensure a satisfactory backup surface to the
veneer panels with integrated reinforced stone installation. (Industry standard: 1/8" in
backers, which have a limited availability of up 10'-0" with no more than 1/32" between
to 5' x 10'. individual stones.)

2016 Marble Institute of America Vertical Surfaces/Interior Stone Wall Cladding • Page 15-11
3.7 Masonry Backup. May be poured-in- base stone remains prominent. It may be
place concrete, hollow concrete block, brick, profiled or otherwise decorated to achieve
or other solid masonry surface. Normally, architectural effect. The base must be
stone installation with this substrate will be set separated from the floor with a “soft” joint
with a cavity. appropriately sized to accommodate
anticipated building movements and prevent
3.8 Metal Studs. Must be 16 gauge or damage to either the horizontal or vertical
thicker. Stone anchors may attach directly to surface.
the studs, or a horizontal track component may
be used to carry the load of the anchor to 4.3 Installation. Stone panels may be solid
several studs. May use plywood, cementitious set or standard set (with a cavity) to the
backer board, or gypsum board as a non- substrate. Normally, standard set is the more
loadbearing sheathing. economical method, and is most commonly
employed. The solid-set method is seldom
3.9 Wood Studs. Stone anchors may used, except for installing wainscot or in
attach directly to the studs, or a horizontal certain wet or special circumstance area
track component may be used to carry the load conditions. In the standard-set method, space
of the anchor to several studs. May use allowed between the substrate and the back
plywood, cementitious backer board, or face of the stone may be as little as 1". Wider
gypsum board as a non-loadbearing sheathing. spaces over 2" should have strap anchors
instead of twisted-wire anchors.
3.10 Mechanical Systems. Each
mechanical system is different. Follow 4.4 Weight Relief. Stone panels should
Manufacturer’s recommendations. have their weight relieved when spanning
openings over windows or doors, at all floor
3.11 Wet Areas. Avoid the use of plywood lines, at any expansion joints in the substrate,
or gypsum board as substrate materials. or at 12' to 15’ intervals in height.
Provide a moisture barrier. Suitable substrates
are masonry backup and cementitious backer
board on metal or wood studs. Apply 5.0 STONE TILE
appropriate water proofing membranes to all
substrates. 5.1 Color Differential. Stone tiles are
subject to manufacturing processes different
than other dimension stones and natural stone
4.0 STONE PANELS veneer panels. There is greater latitude in the
acceptability of shaded stones, and Installers
4.1 General. Stone panels that cover a wall should obtain approval of the stone layout prior
(wall die) or a lower portion of a wall to installation.
(wainscot) are supplied in several standard as
well as custom thicknesses depending on the 5.2 Installation. Stone tile may be
stone, its location on the wall, and its use in the installed in almost any location for which stone
project. Normally, stone thickness of ¾" is panels are considered. The exception is for
sufficient. In some instances of very large or elevations higher than 15'-0", which require
fragile stones, thickness of 1¼" or greater may anchors. Thin stone tiles are not suitable for
be necessary. use with anchors. Stone tile may be installed in
a full mortar bed, in a thin-set mortar bed, or
4.2 Base. The base may be in coplanar with an approved adhesive.
position with the wainscot or die or be offset
so that a portion or all of the top edge of the

Page 15-12 • Vertical Surfaces/Interior Stone Wall Cladding 2016 Marble Institute of America
5.3 Back Buttering. For all applications,
the stone tile shall be back buttered to achieve,
as close as practical, 100% adhesive contact
between the stone and the backup.

5.4 Size. Tile patterns shall be laid out so

that no perimeter tile is less than ½ the width
of the typical stone tile, except at the front of
cutouts.

5.5 Substrates. Suitable substrates for

stone tile are masonry, cementitious backer
board, and gypsum board. Do not use gypsum-
based products in wet areas.

5.6 Fire Rating. Two (2) layers of gypsum

board are required in elevator shaft walls and
where a fire rating is required.

6.0 LIGHTWEIGHT NATURAL

STONE VENEER PANELS
6.1 Definition. This product is a bi-
material panel using a thin (±5 mm) stone face
adhesively bonded to a lightweight aluminum
backer. Most stone varieties and finishes are
available, although each manufacturer has
several preferred stones available in their
offerings.

2016 Marble Institute of America Vertical Surfaces/Interior Stone Wall Cladding • Page 15-13
NOTES:

Page 15-14 • Vertical Surfaces/Interior Stone Wall Cladding 2016 Marble Institute of America
VERTICAL SURFACES – 2.0 PRODUCT DESCRIPTION
INTERIOR STONE BASE 2.1 Basic Use. Lowest or bottom part of
structural elements such as columns, piers, and
walls.
1.0 INTRODUCTION
2.2 Fabrication. Stone base units are
1.1 Installation Methods. There are fabricated to dimensions specified on shop
several methods by which interior stone base drawings, prefinished, and delivered to the job
can be installed. Consideration should be given site ready to be cut into required lengths for
to the various features of each method in installation.
making a selection for a specific installation.
See information about installation methods on 2.3 Finishes. Exposed surfaces and edges
the following page, and illustrations of are to be finished with any typical stone finish,
examples at the close of this section. usually polished.
1.2 Delivered ready to install. 2.4 Colors. Most of the commercially
Generally, stone base is cut to required lengths available varieties are suitable.
by the fabricator, based on job-site
measurements furnished by the stone 2.5 Sizes. Thicknesses of 3/8", ½", ¾",
contractor, and delivered to the job site ready 7/8", 1¼", or as specified.
to install.

1.3 Exposed stone edges must be gauged 3.0 TECHNICAL DATA

to the precise thickness specified. Gauging
tolerance cannot be over ±1/32". 3.1 Each stone variety used for interior
stone base should conform to the applicable
1.4 White portland cement is ASTM standard specification and the physical
recommended for light-colored granite and requirements contained therein. The
marble. White portland cement with a low specification for each stone type follows:
alkali content is recommended for limestone.
3.1.1 Granite: ASTM C615, Standard
1.5 For additional information, refer Specification for Granite Dimension Stone
to Chapter 13, Installation General
Information. 3.1.2 Limestone: ASTM C568, Standard
Specification for Limestone Dimension Stone
1.6 Geographic Methods. Some
installation methods and materials are not 3.1.3 Marble: ASTM C503, Standard
recognized and may not be suitable in some Specification for Marble Dimension Stone
geographic areas because of local trade
practices, building codes, climatic conditions, 3.1.4 Quartz-based Stone: ASTM C616,
or construction methods. Therefore, while Standard Specification for Quartz-based
every effort has been made to produce accurate Dimension Stone
guidelines, they should be used only with the
independent approval of technically qualified 3.1.5 Serpentine: ASTM C1526, Standard
persons. Specification for Serpentine Dimension Stone

3.1.6 Slate: ASTM C629, Standard

Specification for Slate Dimension Stone

 2016 Marble Institute of America Vertical Surfaces/Interior Stone Base • Page 15-15
3.1.7 Soapstone: No ASTM Standard exists
at this time

3.1.8 Travertine: ASTM C1527, Standard

Specification for Travertine Dimension Stone

4.0 INSTALLATION

4.1 Methods. Interior stone base can be

installed either by the standard set method or
the thin-set method.

4.2 Joints. Joints are pointed with white

cement, grout, or nonstaining sealant. Joint
width must be specified.

4.3 General Precaution. During

construction, the General Contractor shall
protect all stone from staining and damage.

NOTES:

Page 15-16 • Vertical Surfaces/Interior Stone Base  2016 Marble Institute of America
NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

VERTICAL SURFACES - recommended due to the concentrated internal
stresses experienced by the stone. In extreme
STONE SOFFITS cases these stresses can be great enough to
fracture the stone panel.
1.0 INTRODUCTION
2.6 Fascia Courses. Soffit stone of limited
1.1 Installation Methods. There are dimension may be attached to the fascia course
several methods by which stone soffits can be by mechanical methods. Soffit stones of
installed. Consideration should be given to the greater dimension may induce unacceptable
various features of each method in making a rotational forces on the fascia stone. Reliance
selection for a particular installation. See on adhesive attachment alone is not allowed.
detailed illustrations of examples at the close of
this section. 2.7 Movement Joints: When anchoring
soffit stones to overhead structure, care must
be taken to recognize differential movement
2.0 DESIGN CRITERIA between floors and other structural elements.
Movement joints must be adequately sized and
2.1 Anchoring and Installation. Each accurately located to accommodate all
soffit stone should be independently anchored anticipated movements. Ensure that
and installed. When designing stone soffits, movement joints are free of shims or other
allow ample space above soffit for anchoring to materials capable of transferring loads across
the structure. Anchor quantity, type, and the joint between the stones.
position shall be determined by load calculation
and anchor strength, allowing adequate factors
of safety in the design. 3.0 PRECAUTIONS
2.2 Soffit stones experience flexural 3.1 Only sound stone varieties should be
stress due to gravity induced loads. Unlike used. Marble for soffit conditions is limited to
windload, gravity loads are constant, and soundness classification Group “A” and “B”
therefore allowable stresses in the stone panel marbles. If the soundness of any proposed
design should be reduced to eliminate creep stone cannot be reliably verified, other means
deformation. of reinforcement will be necessary.

2.3 Free spanning, exterior soffit 3.2 All stone soffit panels are to be
stones of limited thickness may not have mechanically anchored. Thin-setting thin
enough mass to resist uplifting forces caused by stone tiles in soffit and ceiling applications is
high wind conditions. It is therefore necessary not recommended without the specific
to mechanically anchor the stone to resist endorsement of the thin-set manufacturer.
upward in addition to downward forces.
3.3 For additional information, refer
2.4 Soffit installations encounter combined to Chapter 13, Installation General
gravity and windloads working in the same Information.
direction. For this reason, fabrication
tolerances with reference to panel thickness 3.4 Geographic Methods. Some
and anchor prep offset from panel face may installation methods and materials are not
become critical in soffit installations. recognized and may not be suitable in some
geographic areas because of local trade
2.5 Caution. The use of wedge-type or practices, building codes, climatic conditions,
expansion anchors in stone panels is not or construction methods. Therefore, while

 2016 Marble Institute of America Vertical Surfaces/ Stone Soffits • Page 15-17
every effort has been made to produce accurate 5.1.3 Marble: ASTM C503, Standard
guidelines, they should be used only with the Specification for Marble Dimension Stone
independent approval of technically qualified (Soundness Groups A & B)
persons.
5.1.4 Quartz-based Stone: ASTM C616,
Standard Specification for Quartz-based
4.0 PRODUCT DESCRIPTION Dimension Stone

4.1 Basic Use. Horizontal underside of 5.1.5 Slate: ASTM C629, Standard
structural elements such as beams, arches, and Specification for Slate Dimension Stone
cornices.
5.1.6 Serpentine: ASTM C1526, Standard
4.2 Fabrication. Soffits are precut and Specification for Serpentine Dimension Stone
prefinished to dimensions specified on shop
drawings, and delivered to the job site ready to 5.1.7 Travertine: ASTM C1527, Standard
install. Specification for Travertine Dimension Stone

4.3 Finishes. Polished, honed, abrasive,

thermal, and natural cleft for interior use; 6.0 INSTALLATION
honed, abrasive, thermal, natural cleft, rough,
and textured for exterior use. Polished marble 6.1 Preparatory Work. The General
or limestone is not recommended for exterior Contractor must furnish suitable structural
use. substrate to accommodate loads imposed upon
it by the soffit anchorage.
4.4 Colors. Most of the commercially
available varieties are suitable. 6.2 Method. Soffits can be installed by
conventional anchorage techniques or
4.5 Sizes. Thicknesses of 1¼", 1½", 2", or preassembled systems. Anchors shall be of
greater are common. The actual required non-staining and corrosion resistant metals.
thickness is subject to the strength and 6.2.1 Each soffit stone should be
durability of the selected stone. independently anchored and installed.

6.2.2 Joint widths shall be a minimum of

5.0 TECHNICAL DATA 1/4". Wider joints are frequently required to
accommodate thermal expansions and/or
5.1 Each stone variety used for soffits should building movements. Caulk with nonstaining
conform to the applicable ASTM standard sealant.
specification and the physical requirements
contained therein. The specification for each 6.3 General Precaution. During
stone type are as follows: construction, the General Contractor shall
protect all stone from staining or damage.
5.1.1 Granite: ASTM C615, Standard
Specification for Granite Dimension Stone

5.1.2 Limestone: ASTM C568, Standard

Specification for Limestone Dimension Stone

Page 15-18 • Vertical Surfaces/Stone Soffits  2016 Marble Institute of America

NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

VERTICAL SURFACES - 2.6 Geographic Methods. Some
installation methods and materials are not
STONE FIREPLACE FACINGS recognized and may not be suitable in some
geographic areas because of local trade
practices, building codes, climatic conditions,
1.0 INTRODUCTION or construction methods. Therefore, while
every effort has been made to produce accurate
1.1 Methods. There are several methods guidelines, they should be used only with the
by which stone fireplace facings may be independent approval of technically qualified
installed. Consideration should be given to persons.
each method when making a selection for a
specific installation. See information about
installation methods on the following page, and 3.0 PRODUCT DESCRIPTION
illustrations of examples at the close of this
section. 3.1 Basic Use. As interior stone fireplace
facings for commercial, institutional, and
residential use.
2.0 DESIGN CRITERIA
3.2 Finishes. Polished, honed, natural
2.1 Fireplace headers and legs cleft.
(uprights) may be thin-set if stone is no thicker
than ½". Fastening of stone slab thicker than 3.3 Colors. Most of the commercially
½" must be mechanical unless specifically available varieties are suitable.
designed and approved by the thin-set
manufacturer. 3.4 Sizes. Thicknesses of 3/8", ½", ¾",
7/8", 1¼", or as specified.
2.2 Exposed stone edges must be gauged
to the precise thickness specified. Gauging
tolerance cannot be over ±1/32". 4.0 TECHNICAL DATA
2.3 Backup Materials/Temperature. 4.1 Each stone variety used for fireplace
Cracking of fireplace facings is primarily due to facings should conform to the applicable ASTM
expansion and contraction of backup materials. standard specification and the physical
Ensure that stone surface temperatures do not requirements contained therein. The
exceed ability to safely and comfortably touch specification for each stone type are as follows:
the stone facing when a fire is burning in the
fireplace. Setting space between stone and 4.1.1 Granite: ASTM C615, Standard
backup should be at least ¾". Specification for Granite Dimension Stone
2.4 White portland cement is 4.1.2 Limestone: ASTM C568, Standard
recommended for light-colored granite and Specification for Limestone Dimension Stone
marble. White portland cement with a low
alkali content is recommended for limestone. 4.1.3 Marble: ASTM C503, Standard
Specification for Marble Dimension Stone
2.5 For additional information, refer
to Chapter 13, Installation General 4.1.4 Quartz-based Stone: ASTM C616,
Information. Standard Specification for Quartz-based
Dimension Stone

 2016 Marble Institute of America Vertical Surfaces/Stone Fireplaces • Page 15-19

4.1.5 Slate: ASTM C629, Standard
Specification for Slate Dimension Stone

4.1.6 Serpentine: ASTM C1526, Standard

Specification for Serpentine Dimension Stone

4.1.7 Soapstone: No ASTM Standard exists

at this time

4.1.8 Travertine: ASTM C1527, Standard

Specification for Travertine Dimension Stone

5.0 INSTALLATION

5.1 Standard Set System. Stone facings

are set firmly against mortar spots located at
anchors.

5.2 Thin Set System. A nonstaining

adhesive should be spread over the backup wall
with a notched trowel and the stone facing
positioned plumb against the adhesive. Used
for stone no thicker than ½".

5.3 Back Buttering. For all applications,

the stone tile shall be back buttered to achieve,
as close as practical, 100% adhesive contact
between the stone and the backup.

5.4 General Precaution. During

construction, the General Contractor shall
protect all stone from staining and damage.

Page 15-20 • Vertical Surfaces/Stone Fireplaces  2016 Marble Institute of America

WET AREAS – products are acceptable. Moisture sensitive
stones should not be used in wet areas.
GENERAL INFORMATION
2.2.1 Avoid use of stones that are flawed.
1.0 INSTALLATION OF DIMEN- Moisture can travel through the flaw to the
SION STONE IN WET AREAS back face of the stone. Do not use Marble
Soundness Classifications “C” or “D” stones, or
This chapter of the Marble Institute of stones that have adhered fiberglass mesh
America’s Dimension Stone Design Manual reinforcement.
includes general notes and references that
apply to the installation of natural stone in wet 2.2.2 Steam Showers. Soundness
areas (urinal, toilet and shower partitions, slab Classifications C and D marbles used in steam
and tile showers, steam rooms and steam showers and around whirlpool tubs have a
showers). This chapter should be used in tendency to lose their fillings due to moisture,
conjunction with chapter 13, Installation – heat, and vibration. Stone tile with adhered
General Information. fiberglass mesh reinforcement on their back
surfaces are not to be used for steam shower
1.1 Installation Methods. There are applications.
several methods by which stone partitions and
showers can be installed.1 Consideration 2.2.3 Mesh Backing. Producers frequently
should be given to the various features of each apply fiber mesh reinforcement to the back
method in making a selection for a specific surfaces of stone tiles and slabs to reduce
installation. For more information about breakage and also increase safety when
installation methods, see the detail drawings at handling large slabs. Caution should be used
the end of the chapter. when handling these stones. Mesh and resin
backing require special consideration when
1.2 Labor Assignment. In most regions of adhesives are chosen. Confirm compatibility of
the United States, the labor body responsible adhesive prior to setting units of this type. Slabs
for installing a stone product will change with mesh backing should not be used in free
pending if the stone product is a tile or a cut- standing vertical applications.
to-size product. Labor jurisdiction practices
vary regionally and locally, so research is 2.3 Anchors. An alternate system that may
encouraged to ascertain the labor group be used is non-staining, corrosion-resistant
assigned to the field installation of a given dowels, pins, and wire anchors in lieu of
product. standard commercial hardware. The design of
these systems must provide for the transfer of
2.0 DESIGN CRITERIA loads from the stone through the anchor to the
2.1 Oil-based putty and plumbing building structure.
sealants should never be used in contact with
stone. 2.4 White portland cement is
recommended for most light-colored natural
2.2 Sound Stones. Only sound stones, stone. White portland cement with a low alkali
free of any cracks, defects, geological flaws, content is recommended for limestone.
and voids should be used. Variations in natural

1 The Marble Institute of America endorses the use Installation Methods” section in the current edition
of a partial list of details published by the Tile of the TCNA Handbook for Ceramic, Glass, and Stone
Council of North America. For additional Tile Installation.
installation information, see the “Natural Stone Tile
 2016 Marble Institute of America Wet Areas/Stone Toilet Partitions • Page 16-1
2.5 Use cement backer board instead of 3.1.6 Serpentine: ASTM C1526, Standard
water-resistant drywall board (green board). Specification for Serpentine Dimension Stone.
Drywall will degrade and the paper on it will
become a food source for mold and mildew 3.1.7 Slate: ASTM C629, Standard
when subjected to moisture. Do not use Specification for Slate Dimension Stone.
“green board” or any gypsum-based product 3.1.8 Soapstone: No ASTM Standard exists
unless a waterproof membrane completely at this time.
protects the surface from moisture infiltration.
3.1.9 Travertine: ASTM C1527, Standard
2.6 Positive water movement. All Specification for Travertine Dimension Stone.
horizontal surfaces (e.g., seats, sills, curbs,
etc.) must slope toward drain or toward other 4.0 TERMINOLOGY
surfaces sloped toward a drain.
4.1 Definitions.
2.7 Geographic Methods. Some 4.1.1 Hot mop. A substrate employing layers
installation methods and materials are not of asphalt applied while hot to create a
recognized and may not be suitable in some waterproof barrier.
geographic areas because of local trade
practices, building codes, climatic conditions, 4.1.2 Cold applied membrane. A liquid
or construction methods. Therefore, while applied bonded membrane, impervious to
every effort has been made to produce accurate water.
guidelines, they should be used only with the
independent approval of technically qualified 4.1.3 Wet set. Tile installation method
persons. prescribed by ANSI A108.1A.
4.1.4 Dry pack. A mortar mixed with
3.0 TECHNICAL DATA inadequate water component to facilitate
3.1 Each stone variety used for stone complete hydration, thereby dependent upon
partitions or shower rooms described in this water of opportunity to complete chemical
chapter should conform to the applicable cure. Dry packs are used due to their
ASTM standard specification and the physical compatibility and greater ability to allow
requirements contained therein. The lateral transfer of water. Dry packs frequently
specification for each stone type follows: include aggregates coarser than sand.

3.1.1 Granite: ASTM C615, Standard 4.1.5 Positive flow. To move along in the
Specification for Granite Dimension Stone. direction of a drain or other planar surfaces
sloped towards a drain.
3.1.2 Limestone: ASTM C568, Standard
Specification for Limestone Dimension Stone. 4.1.6 Negative flow. To move along in the
direction away from a drain or other planar
3.1.3 Marble: ASTM C503, Standard surfaces sloped towards a drain.
Specification for Marble Dimension Stone,
Soundness Classification “A.” 4.1.7 Sheet applied bonded membrane.
A waterproof membrane providing a barrier to
3.1.4 Onyx: No ASTM Standard exists at this positive liquid migration per ANSI A118.10.
time.
4.1.8 Shower pan (membrane or liner).
3.1.5 Quartz-based Stone: ASTM C616, Water containment sheeting per ASTM D4551
Standard Specification for Quartz-based PVC or ASTM D4068 CPE.
Dimension Stone.

 2016 Marble Institute of America Wet Areas/Stone Toilet Partitions • Page 16-2
WET AREAS – 1.8.1 The deflection of the material under
maximum anticipated load shall not exceed
STONE TOILET PARTITIONS L/720.

1.0 PRODUCT DESCRIPTION

2.0 INSTALLATION
1.1 Basic Use. Toilet partitions for all
building types. 2.1 Preparatory Work. A solid substrate
and a structurally adequate plumbing wall
1.2 Fabrication. Stone toilet partitions are should be provided for proper installation.
precut, predrilled, and prefinished to
dimensions specified on the shop drawings and 2.2 Methods. Partitions are assembled
delivered to the job site ready to install. using corrosion resistant hardware. Ceiling-
Certain job conditions make it necessary to suspended units are fastened to structural steel
perform some fabrication steps at the job site. supports in the ceiling. Ceiling-suspended
units may require a metal spline. Floor-
1.4 Types. Partitions may be designed as supported units require concrete floor
floor-supported or ceiling-suspended. construction to secure anchor bolts. Anchorage
methods are to comply with applicable codes.
1.5 Finishes. Polished finish is most
common due to ease of maintenance. See 2.2.1 All joints are filled with non-staining
chapter 3, Stone Selection, for other sealants or grout. Where so specified, joints
commonly available finishes. requiring sealant shall be first filled with an
approved rope backer rod. The backer rod shall
1.6 Colors. Some of the commercially be installed to a depth that provides optimum
available varieties are unsuitable due to sealant profile after tooling.
reduced soundness of the material or
susceptibility to acid attack. 2.3 General Precautions. During
construction, the General Contractor shall
1.7 Sizes. Stone size is limited by the stone protect all stone from staining or damage.
deposit and quarrying method of the selected
stone and design requirements of the specific 2.4 The ceiling channel to which the stile
project. Appropriate stone thickness will be should be attached shall be furnished and
determined by many factors including installed by others.
soundness of the stone, anchorage capacity and
placement, span between supporting 2.5 Unless otherwise noted, channels,
members, etc. head rails, splines, pilasters, threaded pipe and
other fittings are to be supplied by others.
1.8 Technical Information. Every
construction condition requires engineering
based on specific factors for each project–
panel weight, backup material, stone
mechanical and physical properties, etc. The
most stringent code documents always take
precedence. Contact the engineer or
manufacturer of each anchoring system for its
particular technical information and
engineering formulas.

 2016 Marble Institute of America Wet Areas/Stone Toilet Partitions • Page 16-3
WET AREAS – particular technical information and
engineering formulas.
STONE URINAL PARTITIONS
1.7.1 The deflection of the material under
1.0 PRODUCT DESCRIPTION maximum anticipated load shall not exceed
L/720.
1.1 Basic Use. Urinal partitions (or as
junior toilet partitions where doors are not
desired) for all building types. 2.0 INSTALLATION
1.2 Fabrication. Stone urinal partitions 2.1 Preparatory Work. A solid substrate
are precut, predrilled, and prefinished to not more than two inches below finish floor
dimensions specified on the shop drawings and and a plumbing wall should be provided for
are delivered to the job site ready to install. proper installation.
For certain job conditions it is preferable to
finish the stone at the job site. 2.2 Methods. Partitions are available
floor-supported or ceiling-hung. If ceiling-
1.3 Types. Partitions may be designed as hung, the General Contractor shall furnish and
wall hung or floor-supported (with or without install the ceiling channel. Unless otherwise
overhead brace). noted, channels, head rails, splines, pilasters,
threaded pipe and other fittings are to be
1.4 Finishes. Polished finish is most supplied by others
common due to ease of maintenance. See
chapter 3, Stone Selection, for other 2.2.1 Partitions are assembled using
commonly available finishes. corrosion resistant hardware. Floor-supported
units are set on dowels into the finished floor.
1.5 Colors. Some of the commercially Ceiling-hung units are bolted to overhead
available varieties are unsuitable due to support. All ceiling-hung units must have a
reduced soundness of the material or metal spline. Wall-mounted urinal partitions
susceptibility to acid attack. must be attached to the wall at a minimum of
three locations.
1.6 Sizes. Stone size is limited by the stone
deposit and quarrying method of the selected 2.2.2 All joints are filled with non-staining
stone and the design requirements of the sealants or grout. Where so specified, joints
specific project. Appropriate stone thickness requiring sealant shall be first filled with an
will be determined by many factors including approved rope backer rod. The backer rod shall
soundness of the stone, anchorage capacity and be installed to a depth that provides optimum
placement, span between supporting sealant profile after tooling.
members, etc.
2.3 General Precautions. During
1.7 Technical Information. Every construction, the General Contractor shall
construction condition requires engineering protect all stone from staining and damage.
based on specific factors for each project–
panel weight, backup material, stone physical
and mechanical properties, etc. The most
stringent code documents always take
precedence. Contact the engineer or
manufacturer of each anchoring system for its

 2016 Marble Institute of America Wet Areas/Stone Urinal Partitions • Page 16-4
WET AREAS – manufacturer of each anchoring system for its
particular technical information and
STONE SLAB SHOWER engineering formulas.
PARTITIONS
1.7.1 The deflection of the material under
1.0 PRODUCT DESCRIPTION maximum anticipated load shall not exceed
L/720.
1.1 Basic Use. Shower partitions for all
building types.
2.0 INSTALLATION
1.2 Fabrication. Stone shower partitions
are precut, predrilled, and prefinished to 2.1 Preparatory Work. A solid substrate
dimensions specified on the shop drawings and and a plumbing wall should be provided for
are delivered to the job site ready to install. proper installation.
For certain job conditions it is preferable to
finish the stone at the job site. 2.1.1 Waterproofing (ANSI A118.10) is
typically the responsibility of other trades prior
1.3 Types. Partitions may be designed as to installation of stone. Shower pan or
wall hung or floor-supported (with or without waterproof membrane (ANSI A118.10) must
overhead brace). Partitions are also available as be installed to turn up vertical wall surface at
free-standing units with precast terrazzo least 3" above the finished surface of the
receptors. shower curb. The integrity of the waterproof
membrane of the floor up to the curb height
1.4 Finishes. Polished finish is most should be verified by the contractor before
common due to ease of maintenance. See commencing work by flood test per building
chapter 3, Stone Selection, for other and plumbing code requirements per ASTM
commonly available finishes. D5957, “Standard Guide for Flood Testing
Horizontal Waterproofing Installations.” Test
1.5 Colors. Some of the commercially shower pan or waterproof membrane and
available varieties are unsuitable due to the lack drainage fitting for leaks before beginning
of soundness of the material or its susceptibility stone work.
to acid attack.
2.1.2 Shower pan or moisture proofing
1.6 Sizes. Stone size is limited by the stone must be pre-sloped at a minimum pitch of ¼"
deposit and quarrying method of the selected per foot (20 mm per m) to the weep holes of
stone and the design requirements of the the shower drain assembly. Surround the drain
specific project. Appropriate stone thickness with pea gravel or other weep protection to
will be determined by many factors including prevent mortar from blocking weep holes.
soundness of the stone, anchorage capacity and
placement, span between supporting 2.1.3 Partitions are assembled using
members, etc. corrosion resistant hardware. All joints are
sealed with non-staining sealants or grout.
1.7 Technical Information. Every Where so specified, joints requiring sealant
construction condition requires engineering shall be first filled with an approved rope
based on specific factors for each project– backer rod. The backer rod shall be installed to
panel weight, backup material, stone physical a depth that provides optimum sealant profile
and mechanical properties, etc. The most after tooling.
stringent code documents always take
precedence. Contact the engineer or
 2016 Marble Institute of America Wet Areas/Stone Shower Partitions • Page 16-5
2.2 Methods. Stone shower partitions are
to be installed to allow service or replacement
of the partition without damaging adjacent
finished surfaces. Stone shower partitions can
be installed by one of the following methods:

2.2.1 Free-standing units. Partitions are

assembled using corrosion resistant hardware.
All joints are filled with non-staining sealants
or grout.

2.2.2 Floor-supported units. Partitions

are to be set on top of substrate. Floor-
supported units are set on dowels into the
finished floor.

2.3 General Precautions. During

construction, the General Contractor shall
protect all stone from staining and damage.

NOTES:

 2016 Marble Institute of America Wet Areas/Stone Shower Partitions • Page 16-6
WET AREAS – particular technical information and
engineering formulas.
STONE SLAB RESIDENTIAL
SHOWERS, STEAM ROOMS, 1.7.1 Construction of walls and partitions
AND STEAM SHOWERS should be designed to maximum deflection of
L/720 for conditions utilizing thick-set or thin-
set mortar installation methods.
1.0 PRODUCT DESCRIPTION
2.0 INSTALLATION –
1.1 Basic Use. Shower stalls, steam rooms,
and steam showers for residential use.
SLAB SHOWER STALLS

1.2 Fabrication. Parts are precut and 2.1 Preparatory Work. Shower pan or
prefinished to dimensions specified on the shop waterproof membrane (ANSI A118.10) must
drawings and are delivered to the job site ready be installed to turn up vertical wall surface at
to install. For certain job conditions it is least 3" above the finished surface of the
preferable to finish the stone at the job site. shower curb. The integrity of the waterproof
membrane of the floor up to the curb height
1.3 Limitations. Only sound stone should be verified by the contractor before
varieties should be used. Marble selection is commencing work by flood test per building
limited to Soundness Classifications “A” and and plumbing code requirements per ASTM
“B”. D5957, “Standard Guide for Flood Testing
Horizontal Waterproofing Installations.” Test
1.4 Finishes. Polished finish is most shower pan or waterproof membrane and
common due to ease of maintenance. See drainage fitting for leaks before beginning
chapter 3, Stone Selection, for other stone work.
commonly available finishes.
2.1.1 Shower pan or waterproofing must
1.5 Colors. Some of the commercially be pre-sloped to a minimum pitch of ¼" per
available varieties are unsuitable due to the lack foot (20 mm per m) to the weep holes of the
of soundness of the material or its susceptibility shower drain. Surround the drain with pea
to acid attack. gravel or other weep protection to prevent
mortar from blocking weep holes.
1.6 Sizes. Stone size is limited by the stone
deposit and quarrying method of the selected 2.2 Method. Shower stall floor should be
stone and the design requirements of the installed in a dry-pack mortar bed consisting of
specific project. Appropriate stone thickness one part portland cement to four to five parts
will be determined by many factors including sand, 100% coverage of mortar bed material
soundness of the stone, anchorage capacity and between floor and substrate is recommended.
placement, span between supporting Moisture must be able to freely migrate
members, etc. laterally through the mortar bed and discharge
via the weep holes in the shower drain
1.7 Technical Information. Every assembly.
construction condition requires engineering
based on specific factors for each project– 2.3 Stone wall panels are set firmly
panel weight, backup material, stone physical against masonry walls or waterproofed
and mechanical properties, etc. The most surfaces.
stringent code documents always take
precedence. Contact the engineer or 2.4 Joint width can be maintained by
manufacturer of each anchoring system for its using plastic shims. Joints should be at least
 2016 Marble Institute of America Wet Areas/Stone Slab Residential • Page 16-7
1/16" wide and pointed with white cement, Professional design and installation are critical
grout, or non-staining sealant. Joint width to avoid damage to adjacent material due to
must be specified. vapor migration and heat transfer.

2.5 Anchors that contact the stone should 3.1 Waterproofing. A waterproofing
be corrosion resistant metal (stainless steel, membrane (ANSI A118.10) must extend a
copper, bronze, brass, aluminum) and should minimum of 3" above the top of the finished
be securely attached to the structure and the surface of the curb. All backup surfaces must
stone. be waterproofed with a membrane authorized
by the Manufacturer for steam room
2.6 Exposed stone edges must be gauged applications. All horizontal surfaces shall be
to the precise thickness specified. pre-sloped to a minimum pitch of ¼" per foot
(20 mm per m) toward the shower drain
2.7 Face Sealing. Stone residential shower assembly. The integrity of the waterproof
stalls may be sealed or unsealed. membrane on the floor up to the height of the
curb should be verified by the contractor
2.7.1 If sealed, follow Manufacturer’s before commencing work by flood test per
written recommendations for cleaning, building and plumbing code requirements per
stripping, and resealing. The chemicals used ASTM D5957, “Standard Guide for Flood
should contain no acids or harshly alkaline Testing Horizontal Waterproofing
ingredients. Both types destroy the polished Installations.”
finishes on some stone varieties.
3.2 Methods. Stone may be installed by
2.7.2 Sealing does not eliminate the need using any of the approved methods. Exterior
for frequent cleaning of the wall or floor methods must be used in the shower. Avoid
surfaces. A neutral detergent (pH of 7) is the use of gypsum board in shower areas.
recommended cleaning agent.
3.3 Ceilings are to be sloped ½” per foot
2.8 Stone Ceilings. For details and (40 mm per m) up to 2” per foot (170 mm per
information regarding stone ceilings in m) for textured finishes to bring moisture to
residential showers, refer to the “Stone Soffits” the face of the wall opposite the shower head,
section of this Manual in Chapter 15, Vertical or the principal wall(s) of the room. For
Surfaces. example, consider sloping the ceiling away
from the wall including a bench or doorway.
2.9 General Precautions. During Sloping ceiling from the center can minimize
construction, the General Contractor shall rundown on the walls. Large, one-piece
protect all stone from staining and damage. shower ceilings should be supported by the
shower walls. An additional anchor should be
3.0 INSTALLATION – installed at the cutout for the fan or fan/light
SLAB STEAM ROOMS AND combination.
STEAM SHOWERS 3.4 Finished surface must be sloped
Steam rooms are highly specialized toward the shower drain assembly at a
applications. All electrical and plumbing minimum pitch of ¼" per linear foot (20 mm
fixtures should be rated for steam rooms. per m) and a maximum pitch of ½" per linear
Steam rooms for continuous use require a foot (40 mm per m).
membrane (ANSI A118.10) with a water vapor
permeance (perm rating) of 0.5 or less.

 2016 Marble Institute of America Wet Areas/Stone Slab Residential • Page 16-8
3.5 Grout is to be full stone depth. Cured be provided to evacuate moisture from any
grout should not be easily penetrated with a voids which may have developed between the
pocket knife blade. back face of the stone and the substrate.

3.6 Installation materials must be 3.10 Provision for Steam Generator.

authorized by the Manufacturer for steam Oversize the diameter of the hole in the stone
room applications. Water should be potable for the steam pipe a minimum of ¼” (6 mm).
and free of any staining agents. Stone tiles may Center the steam line in the hole and use high
be used. temperature silicone or insulation to act as a
heat barrier between the steam and the stone
3.7 Stone may be installed using any material.
of the following methods:
3.10.1 Install steam shower controller per
3.7.1 A thin-set or medium bed method Manufacturer’s installation instructions. When
on a mortar bed or cementitious backer board installing on cleft or irregular surfaced stone,
for tile only. Setting material suitability may be ensure control is sealed to wall.
affected by the size of stone units to be
installed. Consult with adhesive manufacturer
for specific recommendations. NOTES:
3.7.2 Mortar bed (wet set) method. The
method (ANSI A108.1A) that requires that the
stone be set on a mortar bed that is still plastic.

3.7.3 Mechanically anchored. An

installation system over a waterproofed
backing of scratch coat or cementitious backer
board for pieces greater than 2’ X 2’. Weep
holes should be provided at the base of the
cavity or as shown on architectural drawings,
to evacuate accumulated condensation from
the air space between the back face of the stone
and the substrate. Additionally, openings
should be provided at the top of the installation
to accommodate ventilation of the cavity

3.8 Effects of Steam on Stone and

Anchorage. Steam is a catalyst. Many stones
contain elements and metallic compounds that
will react with steam and form other elements
not common to the stone’s variety. Color
change in background and veining could result,
and the stone’s structural integrity may be
compromised. Use non-corroding hardware in
all conditions where in contact with stone.

3.9 Additional Moisture Control.

Adhered stone should be solid-set to avoid
moisture at the back face. Weep holes should

 2016 Marble Institute of America Wet Areas/Stone Slab Residential • Page 16-9
WET AREAS – 1.7 Technical Information. Every
construction condition requires engineering
STONE TILE RESIDENTIAL based on specific factors for each project–
SHOWERS, STEAM ROOMS, panel weight, backup material, stone physical
AND STEAM SHOWERS and mechanical properties, etc. The most
stringent code documents always take
precedence. Contact the engineer or
1.0 PRODUCT DESCRIPTION manufacturer of each anchoring system for its
particular technical information and
1.1 Basic Use. Shower stalls, steam rooms, engineering formulas.
and steam showers for residential use.
1.7.1 The deflection of the material under
1.2 Fabrication. Parts are precut and pre- maximum anticipated load shall not exceed
finished to dimensions specified on the shop L/720.
drawings and are delivered to the job site ready
to install. 1.8 Exposed stone edges must be gauged
to the precise thickness specified.
1.3 Limitations. Only sound stone
varieties, including Soundness Classification 2.0 INSTALLATION –
Groups A and B marbles, should be used. Stone
tile with adhered fiberglass mesh
TILE SHOWER STALLS
reinforcement on their back surfaces are not to
be used for shower applications. Due to the 2.1 Preparatory Work. Shower pan,
nature of stone tile production, it can be waterproof membrane (ANSI A118.10), or
expected that wide ranges in color and veining vapor retarder membrane (ANSI A108.02-
will occur. It is unreasonable to expect the 3.8) must be specified (see current TCNA
Installer to produce specific matching patterns B414 STONE for details). Turn shower pan
or strict adherence to a specific range of colors membrane up vertical wall surface at least 3"
from tiles pulled one by one out of a carton above the finished surface of the shower curb
unless specific instructions are given and (6” above floor in showers without curbs). The
agreed to before the installation is begun. integrity of the waterproof membrane up to
the height of the curb should be verified by the
1.4 Finishes. Polished finish is standard. contractor before commencing work by flood
See chapter 3, Stone Selection, for other test per building and plumbing code
commonly available finishes. requirements per ASTM D5957, “Standard
Guide for Flood Testing Horizontal
1.5 Colors. Most of the commercially Waterproofing Installations.”
available varieties are suitable. However, some
varieties are unsuitable due to the reduced 2.2 Method. Shower stall floor should be
soundness of the material or susceptibility to installed in a dry-packed mortar bed consisting
acid attack. of one part portland cement to four to five
parts sand. 100% coverage of mortar bed
1.6 Sizes. Stone size is limited by the stone material between floor and sub-slab is
deposit and quarrying method of the selected recommended.
stone and the design requirements of the
specific project. Appropriate stone thickness 2.2.1 Shower pan membrane must be
will be determined by many factors including sloped toward the shower drain assembly at a
soundness of the stone, anchorage capacity and minimum pitch of ¼" per linear foot. Finished
placement, span between supporting surface must be sloped toward the shower
members, etc. drain assembly at a minimum pitch of ¼" per
 2016 Marble Institute of America Wet Areas/Stone Tile Residential • Page 16-10
linear foot (20 mm per m) and a maximum Steam rooms for continuous use require a
pitch of ½" per linear foot (40 mm per m). membrane (ANSI A118.10) with a water vapor
permeance (perm rating) of 0.5 or less.
2.2.2 A plumb, properly waterproofed Professional design and installation are critical
backup wall with a maximum variation of 1/8” to avoid damage to adjacent material due to
in 8'-0" must be provided. Thinset adhesive is vapor migration and heat transfer.
spread over the substrate with a notched
trowel, and the stone tile is put into place with 3.1 Installation materials must be
a slight twisting motion. For all applications, authorized by the Manufacturer for steam
the stone tile shall be back buttered to achieve, room applications. Water must be free of
as close as practical, 100% adhesive contact metals and should be potable.
between the stone and the backup.
3.2 Preparatory Work. Shower pan
2.3 Joint width can be maintained by (ANSI A118.10, ASTM D4068 or D4551 and
using plastic shims. Joints should be at least meeting applicable building codes) must be
1/16" wide. Joint width must be specified. specified (see current TCNA SR613 or SR614
for details). Turn shower pan membrane up
2.4 Movement Joints (Architect must vertical wall surface at least 3" above the
specify type of joint and show location and finished surface of the shower curb (6” above
details on drawings). Movement joints are floor in showers without curbs). The integrity
mandatory according to TCNA EJ171. of the waterproof membrane up to the height
of the curb should be verified by the contractor
2.5 Sealing. Stone tiles installed in before commencing work by flood test per
residential showers may be sealed or unsealed, building and plumbing code requirements per
according to the Owner’s preference. ASTM D5957, “Standard Guide for Flood
Testing Horizontal Waterproofing
2.5.1 If sealed, follow Manufacturer's Installations.”
written recommendations for cleaning,
stripping, and resealing. The chemicals used 3.3 Stone tile may be installed using
should contain no acids or harshly alkaline any of the following methods:
ingredients. Both types destroy the polished
finishes on some stone varieties. 3.3.1 Thin-set or medium set method on a
mortar bed or cementitious backer board.
2.5.2 Sealing does not eliminate the need
for frequent cleaning of the wall or floor 3.3.2 A full mortar bed. A full mortar bed
surfaces. A neutral detergent (pH of 7) is the or wet set method (ANSI A108.1A) that
recommended cleaning agent. requires that the stone be set on a mortar bed
that is still plastic.
2.6 General Precautions. During
construction, the General Contractor shall 3.3.3 Tiles as thin as 3/8" may be used.
protect all stone from staining and damage. Reference current edition of TCNA Handbook
for Ceramic, Glass, and Stone Tile Installation for
3.0 INSTALLATION – TILE additional details.
STEAM ROOMS AND STEAM
3.4 Effects of Steam on Stone. Steam is
SHOWERS
a catalyst. Many stones contain elements and
metallic compounds that will react with steam
Steam rooms are highly specialized
and form other elements not common to the
applications. All electrical and plumbing
stone’s variety. Color change in background
fixtures should be rated for steam rooms.
 2016 Marble Institute of America Wet Areas/Stone Tile Residential • Page 16-11
and veining could result, and the stone’s WET AREAS –
structural integrity may be compromised. Use
non-corroding hardware in all conditions ACCESSORIES AND STONE
where in contact with stone. PENETRATIONS
3.5 Moisture Proofing. Stone should be
solid-set to avoid creating a moisture collection 1.0 ACCESSORIES
cavity at the back face. 1.1 Accessories must meet all applicable
building codes and be installed per Manu-
3.6 Ceilings are to be sloped ½” per foot facture’s recommendations.
(40 mm per m) up to 2” per foot (170 mm per
m) for textured finishes to bring moisture to 1.2 Manufacturer's standard design hardware
the face of the wall opposite the shower head, and accessories shall be made of non-corroding
or the principal wall(s) of the room. For materials.
example, consider sloping the ceiling away
1.3 All built-in seats, sills, curbs, etc., shall be
from the wall including a bench or doorway.
waterproof and installed over a pre-sloped, flashed,
Sloping ceiling from the center can minimize
waterproof membrane. Finish surface and substrate
rundown on the walls.
should have a minimum slope of ¼” per foot (20
mm per m) toward the drain.
3.7 Slope shower pan membrane a
minimum of ¼" per foot (20 mm per m) to 1.4 All built-in seats, sills, curbs, etc., must be
weep holes in drain. dimensionally stable when moist and structurally
sound.
3.8 Grout is to be full stone depth.

3.9 Provision for Steam Generator. 2.0 PENETRATIONS

Oversize the diameter of the hole in the stone 2.1 Penetrating the waterproof system or the
for the steam pipe a minimum of ¼” (6 mm). stone is often necessitated for the installation of
Center the steam line in the hole and use high recessed niches, all features of niches (e.g. shelves,
temperature silicone or insulation to act as a lights), and corner seats, grab bars, fans or fan/light
heat barrier between the steam and the stone combinations, etc.
material.
2.2 All openings, cut-outs or protrusions
3.9.1 Install steam shower controller per through the waterproofing system should be sealed
Manufacturer’s installation instructions. When with a suitable flexible sealant.
installing on cleft or irregular surfaced stone,
2.3 Any opening penetrating the water-proof
ensure control is sealed to wall.
envelope must be flashed and sealed to become an
integral part of the system.
2.4 Any penetrations through the stone shall be
made waterproof with a non-staining flexible
sealant.

 2016 Marble Institute of America Wet Areas/Stone Tile Residential • Page 16-12
NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

RESIDENTIAL STONE 2.3 Marbles are traditionally prized for
their aesthetic appeal, accentuated by
COUNTERTOP pronounced veining trends and often bold
INSTALLATION colors. These stones are calcium carbonate-
based, made up principally of the calcite
crystal. Due to their mineralogical makeup, all
1.0 INTRODUCTION marbles are vulnerable to either abrasion or
chemical attack. Abrasive attack occurs most
commonly from common kitchen utensils, and
1.1 The beauty and permanence of natural
can be prevented with the judicious use of
stone countertops are enjoyed by many. The
protective cutting boards and similar measures.
full potential of these installations is realized
The use of cleaners containing abrasives must
only when the selection, design, fabrication,
be avoided. Chemical attack is most
and installation are completed by, or with the
commonly brought about by exposure to acidic
consultation of, qualified and experienced
solutions, such as lemon juice, tomatoes,
individuals. This document has been prepared
vinegar, etc. The use of inappropriate cleaning
and published by the Marble Institute of
agents may also trigger acidic attack. Acidic
America to guide the user in the correct means
solutions can permanently etch the surface of
and methods of using natural stone as a
the material. The application of an
countertop surface.
impregnating sealer may reduce the
vulnerability to acidic attack, but it will not
eliminate it.
2.0 STONE MATERIALS
2.1 Varieties. All varieties of dimension 2.4 Serpentines are similarly prized for
stone have been used successfully for their veining and color. Historically, this rock
countertop surfaces. Different types of stone type had been commercially grouped with
have specific properties that offer advantages or marble. However, serpentine is not true
disadvantages in various applications. The marble geologically. See Chapter 9, Geological
following is a brief overview of the common Classification, for distinguishing characteristics
varieties of dimension stone. of serpentine. Due to their mineralogical
difference, serpentines generally have
2.2 Granites are undoubtedly the most improved abrasion and chemical resistance
popular stone type used in countertop over true marbles.
applications today. This group of stones, in a
commercial sense, includes many stone 2.5 Onyx, also prized for its color and
materials that are not true granites by veining, is perhaps best known for its
geological definition. For example, gabbro, translucent properties allowing for stunning
anorthosite, gneiss, diabase, and diorite would effects when backlit in the application. Like
be commercially sold as granite due to similar several other rock varieties, onyx was
working and performance properties. These traditionally commercialized as marble,
are some of the hardest of the common despite its notable differences. Refer to section
dimension stones, offering high levels of 1.2 of the Geological Classification section in
resistance to abrasion and scratching. The Chapter 7 for further discussion of onyx
primary minerals in granite materials are mineralogy. Due to its cryptocrystalline grain
resistant to virtually all chemicals commonly structure, when compared to true marbles,
found in a residential setting; however, there onyx tends to have lower levels of resistance to
may be trace minerals present in some granites both chemical and abrasive exposures.
and granite-like stones that are vulnerable to
some acids.

 2016 Marble Institute of America Countertops • Page 17-1

2.6 Soapstone is a metamorphic rock that Follow the recommendations of the
is comprised primarily of talc with varying Manufacturer of the material.
amounts of dolomite, magnesite, and other
minerals. Soapstone generally has a smooth
feel to the touch. It is used for countertops and 3.0 STONE FINISHES
other various building aspects such as sinks and There are several finishes available for natural
heaters. Soapstone is a very popular choice for stone countertops and new finishes appear in
countertops in laboratories and classrooms due the market regularly keeping pace with
to its high resistance to chemicals. Soapstone consumer demands. A description of a few of
has limited hardness and is vulnerable to the finishes commonly available follows:
scratches from abrasives. Soapstone is typically
top treated with a food grade mineral oil to 3.1 Polished: A high gloss, mirror like
retain its luster and to mask small scratches that finish with sharp reflections. This finish is
are often common because of its talc content. achieved using multiple grinding heads and
progressively finer abrasives. A polished finish
2.7 Slates, when referring to true slates, intensifies the color and pattern of natural
have high resistance to chemicals. stone.
Traditionally slates were frequently used as
chemistry laboratory tops due to this chemical 3.2 Honed: A non-reflective, satin-like
resistance. Caution is advised, however, in finish. This finish is achieved using multiple
that not all materials marketed as slates are in grinding heads and progressively finer abrasives
fact true slate, and therefore may not stopping short of a polish. A honed finish shows
demonstrate the superior chemical resistance fewer scratches.
that has been associated with this stone variety.
Being of metamorphic origin, slates are of 3.3 Brushed / Antique / Leather: The
limited hardness and therefore the use of this series of names is not fully
vulnerability to scratching or other abrasive standardized within the industry. From some
attack should be noted. The same precautions sources, they are used interchangeably, while
applying to marbles with regard to abrasive from other sources, they are distinctly different
damage should be applied to slates. processes. Most commonly, they describe a
finish that has been achieved by abrading a
2.8 Limestones and travertines used in smooth (or honed) surface with an abrasive,
countertop applications, being of calcium- often diamond, brush. The resultant finish can
based makeup, will have the same chemical have varying levels of sheen and relief. The
attack vulnerabilities as marbles. Abrasion hardness of the mineral matrix within the stone
damage is also a concern, particularly if the to which it is applied will also affect the final
stone is provided with a polished finish. Many product.
varieties of these stone types have high
absorption rates, and commonly, a sealer will
be applied to retard the rate of water 4.0 CUSTOMER
absorption into the stone.
COMMUNICATION
2.9 Stone tiles can be used as a countertop 4.1 Documentation. As dictated by
surface material, and the finished surface will standard practices of good business,
carry the same precautions as the particular communications with the customer should be
stone type from which it is made. The joint documented in writing.
filler, whether grout, elastomeric sealant,
epoxy or polyester resin, may have specific 4.1.1 As all natural stones are unique, with
requirements for protection and maintenance. pits, fissures, cracks, corrosive minerals, or

Page 17-2 • Countertops  2016 Marble Institute of America

other features that the customer may find 6.0 CABINET AND SUBSTRATE
objectionable, these should be acknowledged REQUIREMENTS
when samples and/or slabs are being viewed.
The customer must be made aware that some Cabinets to receive stone countertops must be
of these features may become more or less permanently affixed in their final position prior
noticeable when the position (vertical or to field measuring for countertops.
horizontal) of the slab is changed, or when the
lighting intensity is changed. 6.1 Measurement Tolerances. Refer to
Chapter 22 for allowable substrate tolerances.
4.2 Customer and Subcontractor When cabinets are not within these tolerances,
Responsibilities. Those items that are a notice to proceed with the installation shall
required to be completed by the customer, or be obtained from the customer (or authorized
by subcontractors coordinated by the representative). Installations done on cabinetry
customer, should be specifically addressed that is outside of these tolerances will have
(e.g., cabinetry installation, plumbing rough- excessive shim spaces and wide regions of filler
in and electrical rough-in). material. Any required aesthetic improvement
to conceal this condition (e.g., additional wood
4.3 Shop Drawings (or facsimile) can trim) is the responsibility of others.
effectively communicate exact cutting
information to the customer. A shop drawing 6.2 Subtops. Fragile stone varieties may
is a highly detailed document that will identify require a full subtop to support the stone.
all aspects of the finished product installation. Generally, sound varieties of granites and
The shop drawing is to be prepared by the marbles falling within soundness classifications
fabricator, showing the layout of the stone A or B can be used in thicknesses of 20 mm or
pieces, location and size of all seams, and greater without the use of a subtop. The
details clarifying all corner and edge treatment presence of unsound veins, cracks, or excessive
conditions. This document can be reviewed by fissuring will mandate the use of a subtop,
the customer prior to commencement of regardless of thickness. Appropriate materials
fabrication. Time constraints of some projects, for subtops are marine-grade plywood,
particularly multi-unit projects, may not allow exterior-grade plywood, waterproofed
for the formal shop drawing preparation and medium-density particle board, or furring
approval processes. In such cases, a copy of the strips. Excessive load-carrying requirements,
field measuring technician’s sketch and notes such as the use of heavy cast-iron sinks, may
may be used in place of the shop drawing. This require the use of either a subtop or auxiliary
document shall be signed by the field measurer framing to carry the weight of the sink and its
upon completion of the field measurement. contents.

4.4 Stone Slab Layout. When working 6.3 Cabinet doors, end panels, and
with highly variegated materials, it may be hardware shall be installed when the field
necessary to invite the customer to participate measurements are made.
in the layout of the actual stone slabs.

7.0 FIELD MEASUREMENTS

5.0 CONTRACTS 7.1 Cabinet Components. Field
5.1 Examples of residential supply contracts measurements are to be taken once all cabinets
can be found in the Introduction of this Manual have been installed in their permanent
and Customer & Sales Forms in the MIA positions. The following related components
Management Tool Kit Series. must be available to the technician at the time
of measurement:

 2016 Marble Institute of America Countertops • Page 17-3

7.1.1 Cabinet Doors cantilevered portion represent more than 1/3
of the width of the countertop. Cantilevered
7.1.2 End Panels countertops exceeding these dimensions will
require corbelled supports beneath the stone.
7.1.3 Cabinet Hardware The exposed underside of cantilevered
portions of countertops will be sawn or
7.1.4 Sinks (and manufacturer-supplied otherwise unfinished surfaces. NOTE: Stones
templates) of lesser soundness may require corbelled
supports for cantilevers that are less than those
7.1.5 Plumbing Fixtures specified herein.

7.1.6 Cook Tops 8.3 Sink Mounts. Sinks are supplied in

one of several types: top mount (or self-
7.1.7 Exhaust Vents (when full-height rimming), undermount and “farm-home.” In
splash is required) the case of the top-mounted sinks, the weight
of the sink and its contents are transferred to
7.1.8 Electrical Outlets (roughed in) the top surface of the stone counter via the rim
of the sink. Undermount sinks can be anchored
to the underside of the stone countertop or
carried by a subtop or auxiliary frame. A
8.0 DESIGN CONSIDERATIONS subtop or auxiliary framing may be required
8.1 Joinery Layout. The layout of the for either design when stones of lesser
joinery of the countertops is extremely soundness are used, or when the sink (with
important to the overall appearance upon contents) is excessively heavy. Refer to details
completion. Being products of nature, slabs of on drawings 17-D-8 through 17-D-11 for
natural stone are limited by the yields of the examples of sink mounting.
quarry in addition to the limitations of the
equipment used in their processing. Most, but 8.4 Edge profiles. Whether shaped by a
not all materials marketed for use as router or a Computer Numeric Control
countertops will be available in lengths up to (CNC) machine, edge profiles add elegance to
±8 ft (± 2.5 m), and some materials are the finished project. Edge profiles with narrow
available in lengths of 10 ft (3 m) or slightly projections and sharp corners are more
greater. Seam location and frequency is susceptible to chipping than those with large
therefore influenced by the available stock for radii. Examples of edge profiles commonly
selected species of material. Details on used are included on drawing 17-D-16. With
drawings 17-D-1, 17-D-2, and 17-D-3 show a machinery and tooling available to modern
variety of joinery schemes. fabrication shops, many custom profiles can be
created which are not shown in this document.
8.2 Spans and Cantilevers. In designs
where part of the countertop is spanning 8.5 Corner Embellishments. Corners of
between supports, the length of the span shall stone countertops can be cut square, cut to a
be limited to 2'-0" (600 mm) for ¾" (20 mm) radius, or projected. Some hand grinding may
stone thicknesses and 3'-0" (900 mm) for 1¼" be required with projected corner designs.
(30 mm) stone thicknesses. In designs where
the countertop is cantilevered beyond the 8.6 Backsplashes. Partial backsplashes
supports (overhanging), the cantilever shall be usually range from 4" to 8". Full-height
limited to 6" (150 mm) for ¾" (20 mm) thick backsplashes cover the entire area between the
countertops and 10” (250 mm) for 1¼" (30 countertop and the upper cabinets.
mm) countertops, but in no case may the Backsplashes are normally made of the same

Page 17-4 • Countertops  2016 Marble Institute of America

thickness as the countertop material. The match between the edge surface and the top
narrow strips will aid in the layout efficiency surface may not be achievable.
and allow for better color match. It also
provides the fabricator better yield. Mixing 9.4 Cutouts for auxiliary equipment
materials of two different thicknesses requires can be made with hand-held or automated
using stone slabs sawn from two different tools. Cutouts shall conform to equipment
blocks, and color variation can be pronounced. templates, with allowable tolerances. In the
interest of safe handling, some cutouts will be
partially or completely performed in the field
9.0 FABRICATION METHODS after installation of the stone.
9.1 Safe Work Practices. All technicians 9.5 Crating and Protection for
involved in the handling and working of stone Transport. The stone materials are to be
materials must receive training in the safe work crated or otherwise protected for transport to
practices (Refer to MIA videos on stone shop the project site. Local transportation laws shall
and slab handling safety). be researched to ascertain tie-down and
clearance requirements when transporting
9.2 Layout and Sawing. The layout stones.
should be marked on the stone slabs using a
temporary mark or by laying physical
templates on the slab. This will roughly
indicate the location and orientation from
10.0 INSTALLATION METHODS
which the finished panels will be sawn. The 10.1 Safe Handling. All technicians
actual finished dimensions of the sawn slabs involved in the handling and working of stone
will be controlled by the sawyer, and materials must receive training in safe work
depending on the sophistication of the available practices.
equipment, may be a digitally controlled
process. The slab thickness is to be sawn 10.2 Dry Assembly. At the project site, it is
through its full depth, in single or multiple recommended that all stone pieces be “dry
passes as required by the equipment used. assembled” in place to verify satisfactory fit
Blade type, rim speed, saw travel rate, and prior to the application of adhesive.
downfeed rates are to be adjusted to provide
the smoothest cut with the least amount of 10.3 Shims are commonly employed to level
chipping possible. the stone countertops. Shim material may be
wood or plastic. Shims must be placed over
9.3 Finishing Of Edge Profiles. Edge portions of the cabinet that are rigid enough
profiles shall be constant in section along the to support it, not over some trim filler
entire length of the countertop. The shaping of portion. Maximum spacing between shims is
the edge is normally done with hand-held 2'-0" (600 mm). Alternatively, longer spacing
routers or with CNC machinery. Some hand between shims may be used if the stone is
grinding is frequently required at inside corner supported with a noncompressible filler
conditions to create a sharp line of reprise. material (usually epoxy or polyester resin).
Edges are to be finished to the same type and This practice is often referred to as “hard
quality of surface as the top, unless a packing.”
contrasting edge surface has been specified for
accent purposes. In the case of resin treated 10.4 Adhesive. The stone countertops are
slabs, some alteration to the color of the edge to be secured to the substrate with a
surface is required to be completed in the nonstaining adhesive. Common construction
fabrication shop. In some cases exact color adhesives or silicone sealant are the most
popular materials used. Construction adhesives

 2016 Marble Institute of America Countertops • Page 17-5

generally provide greater bond strength, while agreements must be documented in writing.
silicone sealants offer slightly more forgiveness Unless otherwise agreed, the tolerances listed
for movements in the substrate. The adhesive in this document shall govern.
material must have a cure rate that is slow
enough to allow final positioning of the stone 11.2 Joint (seam) Widths. Joint width
countertop units. Apply adhesive to within 3" does not include the dimension of an arris on
(75 mm) of all edges and at 6" (150 mm) the stone edge. When an arris is used, the
maximum center-to-center spacing when perceived joint width may be greater that the
installing over a subtop. When installing to the actual width due to the seam filler occupying
cabinet frame without a subtop, apply adhesive the width of the arris.
to all frame members that contact the stone
slab.

10.5 Final Positioning and Joint Filling.

Final positioning of the stone is done either
manually or with the aid of commercially
available stone-alignment tools. The filling of
the seams is normally completed prior to final
positioning of the stone units, allowing the
filler material to extrude out of the joint as the
stones are pulled into alignment. The stone
surface may be masked to prevent contact by
the filler material (refer to MIA Basics of Natural
Stone Countertop Installation video).
11.3 Lippage. The term “lippage,” as used in
10.6 Sealer Application. After the the stone industry, is the planar offset of the
countertops are installed and the seams are finished surfaces of two adjacent stone units.
filled, a sealer or impregnator may be applied. Due to the relatively tight seams used in
Refer to the Maintenance section of this countertop installations, even minor amounts
chapter for further discussion of these of lippage are noticeable. Lippage may be
applications. Alternatively, some fabricators unavoidable due to permanent warp in the slab
prefer to apply the sealer or impregnator in the stock. There should be no detectable lippage at
fabrication shop prior to transporting the the front edge of the countertop. See sketch
pieces to the project site. below for clarification.

11.4 Exposed edges of adjacent stone slabs

11.0 TOLERANCES must be matched in thickness and properly
11.1 Refer to Chapter 22 for allowable installed so that neither the top nor bottom
fabrication and installation tolerances. The surface exceeds lippage tolerances.
tolerances listed in this section are achieved
using skilled tradesmen following standard
industry workmanship practices. Due to
variations in fabrication equipment and stock
availability, these tolerances may not be
achievable, or in some cases, closer tolerances
may be achievable. Therefore, for any
particular project, the supplier and customer
may agree to hold tolerances that are more or
less stringent than those listed herein. Such

Page 17-6 • Countertops  2016 Marble Institute of America

 12.2 Seam Filler Materials. Seams in the
stone countertop are usually filled to the level
of the top surface. The most common filler
materials are polyester resin, epoxy resin and
elastomeric sealant. Elastomeric sealants can
be of silicon, polyurethane, or acrylic bases.
The table below identifies several advantages
and disadvantages of each product.

14 pp. brochure (2012) available from MIA.

12.0 ADHESIVES AND JOINT

FILLERS
12.1 Types. Adhesives used for stone
installation can be either standard construction
adhesives or elastomeric sealant with strong
bonding properties to both the stone and the
substrate. Construction adhesives will
normally provide greater bond strength, while
elastomeric sealants will provide some
forgiveness for movement within the substrate
cabinet. Excessive movement of the substrate,
regardless of the type of adhesive used, will
result in cracking of the seams or stone units.
Verify that the product used does not stain the
stone material.

 2016 Marble Institute of America Countertops • Page 17-7

SEAM FILLER MATERIALS ADVANTAGES & DISADVANTAGES

Product Advantages Disadvantages

Polyester resin  Accepts dyes readily, allowing a  Cures to a high durometer
pleasing color match to stone. hardness which offers little or no
 Leaves joint neatly flush with forgiveness for movement.
counter-top surface.  Limited pot life.
 Can be buffed to a glossy finish that
complements the polished stone
surface.
 Relatively quick cure time.
Epoxy Resin  Leaves joint neatly flush with  Cures to a high durometer
countertop surface. hardness which offers little or no
 Can be buffed to a glossy finish that forgiveness for movement.
complements the polished stone  More difficult to achieve accurate
surface. color match than polyester resin.
 Provides stronger bond than  Long cure time.
polyester resin.  The stone fabric will fail before the
 Long pot life. seam, which is more difficult to
repair.

Grout  Simple to use.  Color may not be consistent

 Long pot life. between batches.
 Relatively easy to dye for color  Cracks easily due to movement.
matching.  Coarse texture contrasts with
polished stone.
 High porosity can be a sanitation
concern.
Elastomeric  Relatively low durometer hardness  Limited to available colors.
Sealant provides significant extension and  Some sealant products contain
(Silicone, compression capability, hence the plasticizers that can migrate into
polyurethane, or greatest accommodation for and stain the stone.
acrylic) movement of any filler material.
 Cures to a glossy surface that
compliments the polished stone
surface

Page 17-8 • Countertops  2016 Marble Institute of America

13.0 STONE TILE COUNTERTOP 13.9 Aprons. Where a stone apron is
INSTALLATION employed and the countertop is designed to
have a radial corner, the apron may be staved
13.1 Subtops. Stone tile countertops must to fit the radius.
have a subtop made of minimum ¾" exterior-
grade plywood or ½" cementitious backer 13.10 Flat Installation. Stone tiles must be
board. Subtop must be flat to within 1/8" in installed flat, side by side, within 1/32" (0.8
10'-0". mm) maximum lippage.

13.2 Edge Treatment. Exposed edges of 13.11 Splashes must be of stone tile,
the countertop may be finished by providing an minimum of 4" high. On stones with obvious
edge profile strip of stone, wood, or metal. vein trend, the vein trend of the splash must be
Where stone is employed, it is to be used as an identical to the countertop below unless
apron to the top surface stone, which limits otherwise specified.
stress on the countertop/apron joint.
13.12 Back buttering of all stone tiles is
13.3 Stone tile tolerances for all stone required. This technique applies a portion of
types must be 1/32" (1 mm) in length, width, the installation material to the back face of the
and thickness. stone. It requires placement of one-half of the
setting material in the case of thin-set mortar,
13.4 Joint Widths. Unless otherwise epoxy, or nonwater-soluble adhesive, or a
agreed, joint widths for stone tile countertops lesser quantity of very rich mortar in the case
must conform to the following: Stone-to-wall of portland cement, to the back of the stone,
joints must be 1/8" (3 mm) in width. Stone- while the balance of the setting material is
to-stone joints must be 1/16" (1.5 mm) applied to the bed. Application should be
minimum, 3/32" (2 mm) maximum, and performed so that one pass is completed in a
uniform from stone to stone. Stone-to- north-south direction, while the second pass is
cabinetry joints must be 1/8" (3 mm) in width. performed in an east-west direction, thus
ensuring, as close as possible, 100% contact of
13.5 Vein Trend. When using stone tiles the stone to the installation bed.
with obvious trend, all tiles shall be installed
with vein trend running in the same direction 13.13 Tile Reinforcement. A common re-
unless otherwise specified. inforcement for stone tiles of limited
soundness is to adhere a fiberglass mesh to the
13.6 Shading Variation. Stone tiles are back surface of the tile. The adhesive used in
subject to manufacturing processes different this application is commonly an epoxy or
from structural stone. There is great latitude in polyester resin. When this type of
the acceptability of shaded stones. Installers are reinforcement is adhered to the tiles, the
cautioned to lay out the stone for inspection Installer must use a thin-set material that will
and obtain approval from the Owner or bond to the resin-impregnated backer. Most
Specifying Authority prior to installation. often this will require an epoxy-based, rather
than a portland-based, thin-set compound.
13.7 Tile Widths. No tile shall be employed
that is less than ½ the width of the stone tile,
except at the front of cutouts, unless previously
discussed with the client.

13.8 Cutouts should be prepared for drop-

in appliances and sinks. Avoid undermounted
sinks, stove tops, etc.

 2016 Marble Institute of America Countertops • Page 17-9

 Mohs Scale stone surface, so that it remains only in
In 1812, the Mohs Scale of mineral hardness depressions and some intercrystalline regions
was devised by the German mineralogist of the slab. The amount of surface area that
Friedrich Mohs (1773-1839), who selected remains as resin varies due to the natural
the ten minerals because they were common features of the material, but it is usually a
or readily available. The scale is not a linear fraction of one percent.
scale, but a relative scale.
14.1.1 The resin used in this process is
Hardness Mineral typically an epoxy, but polyester and acrylic-
1 Talc or Mica based polymers may be used.
2 Gypsum
3 Calcite 14.2 Design Considerations. While the
4 Fluorite intent of this process is to provide a
5 Apatite cosmetically more attractive surface, these are
6 Orthoclase several characteristics of which the fabricator
7 Quartz should be aware:
8 Topaz
9 Corundum 14.2.1 Color. The resin application normally
10 Diamond makes the color of the stone somewhat darker
Source: than an untreated slab. This becomes an issue
American Federation of Mineralogical Societies, Inc. when finishing the edges of the countertop, as
the color of the edge will be lighter in
appearance than the color of the face surface.
Several products are marketed in the industry
14.0 RESIN-IMPREGNATED
for the darkening of the edge, but none have
SLABS been found to be universally successful.
The application of resin to the surfaces of stone
slabs has become an ever-increasing practice. 14.2.2 Interaction with Sealers. There
The intent of this procedure is to fill pits, have been cases of incompatibility between a
cracks, and fissures of natural stones with a given resin and fabricator-applied sealer
glossy resin to enhance the appearance of the combination. This usually results in a “cloudy”
polished slab. When received, the resin or “blotchy” appearance after the sealer
treatment is usually easily detected by viewing product has been applied.
the raw edges of the slab. Evidence of excess
resin is usually visible on the edges of the slab 14.2.3 Structural Flaws. The resin process
if the stone has been treated. can hide cracks or other blemishes which are
structurally influential features of the material.
14.1 Description of Procedure. The Assessment of the structural worthiness of the
process involves screeding the resin on the material can be made more difficult as a result.
surface of the cleaned, sawn slab. This is
frequently done in an automated process, 14.2.4 UV Light Exposure. Nearly all of the
although some suppliers will do this manually. resins currently in use are vulnerable to color
Depending on the equipment used, the slab change or surface degradation when exposed to
may be placed over a large vacuum table to ultraviolet light. These materials are therefore
draw the resin deeper into the stone. The resin not suitable for exterior applications.
is allowed to cure, which may or may not be
accelerated with heat application. Once the
resin has cured, the slab is polished. The
polishing grinds most of the resin from the

Page 17-10 • Countertops  2016 Marble Institute of America

15.0 REINFORCEMENT surface, are required to get the maximum
TECHNIQUES benefit from this technique. A strip of
fiberglass mesh backing is often adhered over
As products of nature, stones have varying the rodded region for additional
strength and behavioral properties. Stones of reinforcement. See detail on drawing 17-D-5.
lesser soundness or stones that have had
substantial areas removed from the slab (e.g,
sink cutouts) will benefit from reinforcement 16.0 ALLOWABLE REPAIR
by a variety of techniques.
Repair of stone countertops must be
15.1 Fiberglass Mesh. A common performed by competent, experienced artisans
reinforcement for stone slabs of limited to achieve the desired results. Repair of the
soundness is to adhere a fiberglass mesh to the stone is permitted when the repaired region is
back surface of the slab. The party doing the not in a structurally significant area of the
sawing of the slabs normally completes this countertop, and when it can be accomplished
process. The adhesive used in this application skillfully so that the repair is consistent in color
is commonly an epoxy or polyester resin. and texture with unrepaired regions of the
slab.
15.2 Liner Blocks. Although not frequently
used in stone countertop construction, a liner 16.1 Fissures occur naturally in many stone
block of stone material can be adhered to the types. A fissure is defined by the American
underside of the stone slabs (when no subtop is Geological Institute as, “An extensive crack,
used) to reinforce seams or other vulnerable break, or fracture in the rock, which may
areas. The liner block need not be of the same contain mineral-bearing material.” The term
type of stone material as the countertop. “fissure” is used commercially in the stone
industry to describe a visible separation along
15.3 Splines. Seams, particularly those intercrystalline boundaries. This separation
between narrow stone pieces, are often splined may start and stop within the field of the stone
together with a steel or stainless steel key. or extend through an edge. A fissure differs
Commonly, a large washer is used as the spline from a crack in that it is a naturally occurring
key. The metal is fully encapsulated with feature in the stone that may be found in other
polyester or epoxy resin and fitted to closely areas of the same slab or other slabs of the same
cut slots in the stone, similar to the “biscuit” material.
joint reinforcements used in woodworking.
16.2 Cracks occur in stones as a result of
15.4 Rodding. A commonly seen method of manmade mechanically induced stresses during
countertop reinforcement is the technique handling, fabrication, transport, or
referred to as “rodding.” Rodding may be installation. When cracks are detected in slab
beneficial to narrow strips of stone material, material prior to fabrication, the best method
such as those in front or behind sink or cook is to simply avoid including them in the
top cutouts. This technique requires a shallow product through culling during the layout
kerf in the underside of the stone slab (See process. In stones with lesser soundness
details on drawing 17-D-5). The kerf is then properties, this option may not be practical, or
closely fitted with a metal or fiberglass rod, possible. When working with such stones it is
which is then fully embedded in epoxy. The common practice to repair cracks by
rod, having greater tensile strength than the cementing them together with epoxy or
stone, helps prevent concave flexure of the polyester resin, either with or without dowel
stone surface. Closely matching the rod size to reinforcement. Cracks that occur as a result of
the kerf size and careful preparation of the rod, handling-induced stresses are often more
including cleaning or abrading the bonding difficult to repair, as they commonly include

 2016 Marble Institute of America Countertops • Page 17-11

chipping in addition to the crack. Repair is degrees of pits, depending on the amount of
frequently performed by injection of a biotite, muscovite, and phlogopite in their
penetrating resin adhesive, which may be dyed composition.
to match the stone, and then rebuffing the area
after curing of the resin. In many cases, the The pits do not make the granite less durable
entire stone must be repolished to make the or otherwise inferior, and do not in themselves
repair unnoticeable. If the repair is attempted qualify the slab for replacement. Pits are
but unsuccessful, the stone is to be replaced common in all granites and should be expected
with a new piece. when dealing with a natural, polished stone
containing several types of minerals with
16.3 Chips can occur in stones either as a different hardnesses. It is usually best to not
result of sawing operations or handling and attempt repair of pits, as most repair
restraint devices. Particularly in the igneous techniques will not cosmetically improve the
stone varieties, the exiting portion of the countertop.
diamond blade will create many small chips. A
small chamfer, called an “arris,” of
approximately 1/16" x 1/16" (1.5 x 1.5 mm) 17.0 MAINTENANCE
can be used to eliminate most of these small
chips. The use of an arris will make the seam 17.1 Application of Sealers. The
appear wider than its actual dimension when application of a topical sealer or impregnator is
filled (see section 11.2, above). Larger chips a common step in decreasing the vulnerability
may be repaired with epoxy or polyester resin of the stone to stains.
if the completed repair is consistent in color
and texture with unrepaired areas of the slab. 17.2 Topical sealers cure as a film on the
In many materials, the resin used in the repair stone surface. Since the material is actually
will appear more natural if it is not dyed. covering the stone, the appearance of the stone
surface may be altered by the application of this
16.4 Pitting of the countertop surface, type of product. This material will provide
particularly in granite material, is a commonly somewhat of a sacrificial layer over the stone,
seen characteristic on natural stone. Granites and will absorb most of the wear on the
are made up of several different minerals, each countertop. Since the sealer is softer than the
mineral having a different hardness. Granites stone, normal use of the countertop will result
contain quartz, feldspars, biotite, amphibole, in abrasion of the sealer surface and dictate
ferrous titanium oxides, and other mineral reapplication to maintain the original luster of
combinations. On the Mohs Scale (see chart the surface. A properly applied topical sealer
above), diamonds are the hardest mineral, with will normally reduce, although not eliminate,
a rating of 10. Quartz and feldspar have a the vulnerability of calcareous stones to attack
hardness of 6.5 to 7 and are very durable. from mildly acidic solutions.
Biotite (small, black minerals throughout the
slab) on the other hand is very soft (2.5) and 17.3 Impregnators will penetrate the stone
flakes easily. All true granites have biotite in and cure a few millimeters below the surface,
their composition. Because biotite is relatively residing in the intercrystalline boundary areas
soft and flaky, the first few layers are often and pores of the stone. These products do not
removed during the polishing process, causing actually “seal” the stone, and are more
pits throughout the slab. Some granites have correctly referred to as a repellent rather than
more biotite throughout their composition a sealer. As such, they are formulated to
than others. The higher the biotite content of prevent transmission of liquids, while allowing
the stone, the more pits it will have. Most transmission of vapor. Since they reside below
polished igneous rocks will have varying the actual surface of the stone, the change to
the appearance of the stone surface is minimal.

Page 17-12 • Countertops  2016 Marble Institute of America

Impregnators will be either hydrophobic, in contain these voids or fissures may harbor
that they repel water-based fluids only, or contaminants which allow the growth of mold
oleophobic, repelling both oil and water-based and mildew. Additionally, the loosening of
fluids. The manufacturer of the impregnator filler materials and in some cases, cracking and
product will recommend a reapplication separating due to thermal and/or freeze/thaw
interval. cycling.

17.4 General Precautions. When any 18.4 Subtops. All areas that are to receive
surface protection product is used, care must stone countertops should have a sub top or
be taken to read and follow the manufacturer’s auxiliary frame made of cement board or
written instructions accurately. This will mortar bed. The subtop or auxiliary framing
provide the greatest benefit from the should include only materials which are rated
application and will guarantee safe handling of for exterior exposure.
the product.
18.5 Adhesives. All adhesives to be used
17.5 Care and cleaning practices of the must be suitable for exterior installations.
stone countertop are to be thoroughly Since silicone is frequently used on outdoor
discussed with the client upon completion of kitchens, care must be taken to ensure that
the installation. Refer to the MIA brochure staining does not result from plasticizer
Care & Cleaning for Natural Stone Surfaces for migration of some silicone products. Polyester
more information. adhesives should be avoided in an exterior
environment.

18.0 OUTDOOR KITCHENS 18.6 Seam Filler Materials. All materials

that are to be used for seam filler must be
18.1 General Precautions. An suitable for exterior installations and allow for
increasingly popular area for stone countertops some movement. Joint widths between
is in outdoor kitchens. The installation of adjacent stone units may be as small as nominal
natural stone countertops in these areas creates 1/16”, but ample accommodation for
additional challenges from the installation of differential movement due to thermal
indoor countertops for suppliers and installers. expansion and contraction must be made at the
Due to extreme temperature changes, possible perimeter of the stone installation.
freeze/thaw cycling, UV exposure and varying
moisture levels, typical installation methods 18.7 Undermount sinks can be anchored to
along with certain materials cannot be used. the underside of the stone countertop or
carried by a subtop or auxiliary frame. A
18.2 Customer Communication. In subtop or auxiliary framing may be required
addition to the prescriptions state earlier in this and should be rated for exterior use.
chapter, customers should be made aware that
due to the use of resins in the finishing process
of natural stone, they will most likely
experience some fading in their countertops.
Nearly all resins used in the fabrication process
are subject to color change and surface
degradation when exposed to UV light See
section 14.2.4.

18.3 Materials. It is recommended that only

sound stones with minimal geological flaws or
voids be used for these areas. Stones that

 2016 Marble Institute of America Countertops • Page 17-13

NOTES:

Page 17-14 • Countertops  2016 Marble Institute of America

NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

 2.5 Corrosion-Resistant Metals. All
COPING AND STOOLS - metals that contact the stone must be
EXTERIOR CUBIC STONE corrosive-resistant.
COPING AND WALLS
2.6 Oil-based putty and sealants should
1.0 INTRODUCTION never be used in contact with stone.

1.1 Installation Method. There are 2.7 White portland cement is

several methods by which cubic coping and recommended for light-colored granite and
walls can be installed. Consideration should be marble. White portland cement with a low
given to the various features of each method in alkali content is recommended for limestone.
making a selection for a specific installation.
See information about installation methods in For additional information, refer to
this section’s Data Sheet, Part 3, and Chapter 13, Installation General Information.
illustrations of examples at the close of this
section. 2.8 Geographic Methods. Some
installation methods and materials are not
recognized and may not be suitable in some
geographic areas because of local trade
2.0 DESIGN CRITERIA
practices, building codes, climatic conditions,
or construction methods. Therefore, while
2.1 Physical Property Values. Final
every effort has been made to produce accurate
design should always be based on specific
guidelines, they should be used only with the
physical property values for the stone to be
independent approval of technically qualified
used. These values may be obtained from the
persons.
Stone Supplier.

2.2 Backup Walls. When exterior cubic

stone is set in conjunction with masonry load- DATA SHEET
bearing walls, the masonry backup should be EXTERIOR CUBIC STONE
solid brick or concrete. If hollow load-bearing
concrete block is used to support and anchor
COPING AND WALLS
stone, it must be reinforced with brick,
concrete, or by filling the voids full of concrete 1.0 PRODUCT DESCRIPTION
two block courses in each story height.
1.1 Basic Use. Exterior masonry walls,
2.3 Bonding. It is recommended for caps, copings, and other cut stonework.
exterior coping that there be 100% coverage of
bonding material between the stone and the 1.2 Fabrication. Exterior cubic stone
substrate. units are precut and prefinished to dimensions
specified on shop drawings, and are delivered
2.4 Bond Stones. For cubic walls, the to the job site ready to install.
effectiveness of bonding is improved when
bond stones are staggered at random. The 1.3 Finishes. Abrasive, honed, and rough
number or percentage of bond stones depends sawn finishes may be used for exterior cubic
on design; from 25% to 30% is generally stone applications.
sufficient. Bond stones should bear on floors
and beams. Provide an open joint at intervals 1.4 Colors. Most of the commercially
for expansion gasket. available varieties are suitable.

 2016 Marble Institute of America Coping and Stools • Page 18-1

Exterior Cubic Stone Coping and Walls
2.0 TECHNICAL DATA mortar. Joints should be raked out to a depth
equal to the width of joint, and later pointed or
2.1 Each stone variety used for cubic stone sealed with an approved, nonstaining sealant.
coping and walls should conform to the
applicable ASTM standard specification and the 3.2.1 Expansion joints should be provided as
physical requirements contained therein. The required and kept free of mortar. Joint width
specification for each stone type follows: may be maintained by using nonstaining,
resilient cushions recessed 1" from exterior
2.1.1 Granite: ASTM C615, Standard face. Joints should be at least 1-1/4" wide,
Specification for Granite Dimension Stone except at control joints, where greater widths
may be required.
2.1.2 Limestone: ASTM C568, Standard
Specification for Limestone Dimension Stone 3.2.2 All anchors, cramps, dowels, pins,
supports, and similar items that contact the
2.1.3 Marble: ASTM C503, Standard stone should be corrosion-resistant metals and
Specification for Marble Dimension Stone should be securely attached to the structure
and to the stone.
2.1.4 Quartz-based Stone: ASTM C616,
Standard Specification for Quartz-based 3.3 General Precaution. During
Dimension Stone construction, the General Contractor shall
protect all stone from staining and damage.
2.1.5 Serpentine: ASTM C1526, Standard
Specification for Serpentine Dimension Stone 3.3.1 Oil-based putty and sealants should
never be used in contact with stone.
2.1.6 Slate: ASTM C629, Standard
Specification for Slate Dimension Stone

2.1.7 Soapstone: No ASTM Standard exists

at this time

2.1.8 Travertine: ASTM C1527, Standard

Specification for Travertine Dimension Stone

3.0 INSTALLATION

3.1 Preparatory Work. Exterior cubic

stone may be installed against an existing
backup or concurrently with the backup wall.
It is recommended that the General Contractor
install continuous flashing for stone coping.

3.1.1 When ready for installation, stones

should be cleaned on all sides, and all dirt and
foreign material removed from all surfaces.

3.2 Methods. Stones should be set in a full

bed of mortar with the vertical joints full of

Page 18-2 • Coping and Stools  2016 Marble Institute of America

Exterior Cubic Stone Coping and Walls
NOTES:

Dimension Stone Design Manual Ó 2016 Marble Institute of America

COPING and STOOLS - DATA SHEET
THIN STONE STOOLS AND THIN STONE STOOLS AND
CUBIC SILLS CUBIC SILLS

1.0 INTRODUCTION 1.0 PRODUCT DESCRIPTION

1.1 Installation Methods. There are 1.1 Basic Use. Interior window stools and
several methods by which stone window stools exterior cubic sills.
can be installed. Consideration should be given
to the various features of each method in 1.2 Fabrication. Stone window stools and
making a selection for a specific installation. cubic sills are precut and prefinished to
See information about installation methods in dimensions specified on shop drawings, and are
this section’s Data Sheet, Part 3, and delivered to the job site ready to install.
illustrations of examples at the close of this
section. 1.3 Finishes. Exposed surface and edges of
thin stone stools shall be polished or honed.
2.0 DESIGN CRITERIA Cubic sills shall be abrasive, honed, or rough
finish.
2.1 Oil-based putty or sealants should
never be used in contact with stone. 1.4 Colors. Most of the commercially
available varieties are suitable.
2.2 Corrosion-resistant Metals. All
metals that contact the stone must be 1.5 Sizes. Thin stone stools shall have
corrosive-resistant. thicknesses of ¾" and 1¼", or as specified.
Cubic sills shall be as specified.
2.3 Bonding. There must be 100%
coverage of bonding material between stone 2.0 TECHNICAL DATA
window stools and substrate.
2.1 Each stone variety used for thin stone
2.4 White portland cement is re- stools and cubic sills should conform to the
commended for light-colored granite and applicable ASTM standard specification and the
marble. White portland cement with a low physical requirements contained therein. The
alkali content is recommended for limestone. specification for each stone type follows:
For additional information, refer to
2.1.1 Granite: ASTM C615, Standard
Chapter 13, Installation General Information.
Specification for Granite Dimension Stone
2.5 Geographic Methods. Some
2.1.2 Limestone: ASTM C568, Standard
installation methods and materials are not
Specification for Limestone Dimension Stone
recognized and may not be suitable in some
geographic areas because of local trade
2.1.3 Marble: ASTM C503, Standard
practices, building codes, climatic conditions,
Specification for Marble Dimension Stone
or construction methods. Therefore, while
every effort has been made to produce accurate
2.1.4 Quartz-based Stone: ASTM C616,
guidelines, they should be used only with the
Standard Specification for Quartz-based
independent approval of technically qualified
Dimension Stone
persons.

 2016 Marble Institute of America Coping and Stools • Page 18-3

Thin Stone Stools and Cubic Sills
2.1.5 Serpentine: ASTM C1526, Standard
Specification for Serpentine Dimension Stone

2.1.6 Slate: ASTM C629, Standard

Specification for Slate Dimension Stone

2.1.7 Soapstone: No ASTM Standard exists

at this time

2.1.8 Travertine: ASTM C1527, Standard

Specification for Travertine Dimension Stone

3.0 INSTALLATION
3.1 Methods: Stone window stools are
installed either by the standard or thin set
method. Cubic sills are installed in a full
portland cement mortar bed with dowels.

3.2 General Precautions: During

construction, the General Contractor shall
protect all stone from staining and damage.

3.2.1 Oil-based putty and sealants should

never be used in contact with the stone.

Page 18-4 • Coping and Stools  2016 Marble Institute of America

Thin Stone Stools and Cubic Sills
NOTES:

 2016 Marble Institute of America Coping and Stools

Thin Stone Stools and Cubic Sills