CURTAINWALL

Products, Performance and

Practicality
(A Wausau AIA-CES Presentation)
 PROGRAM SPECIFICS

Length: One hour

Credits: 1 learning unit (LU)/HSW
Cost: Free - There is no cost to bring this
program to your firm or chapter meeting,
or to take the on-line course
Description: Curtainwall selection, design,
manufacture, and installation are explored
at a basic technical level.
Recommendations for specifications and
application are included. Learn how
curtainwall impacts building LEED®
CURTAINWALL certification.
Objective: Provide design professionals with
valuable information on different types of
Products, Performance and aluminum curtainwall, ease of installation,
movement accommodation, performance,
Practicality and structural integrity.
Point of Contact: For more information or to
(A Wausau AIA-CES Presentation)
schedule a presentation contact Wausau at
info@wausauwindow.com or toll-free at
877.678.2983

Proud Member
 Wausau Window and Wall Systems
is an architectural business unit of
Apogee Enterprises Setting the standard for performance,
craftsmanship and ease of installation,
(Stock symbol APOG on the NASDAQ exchange)
Wausau's engineering and design
professionals ensure each building gets
the window system that is right for its
needs – from pre-engineered, durable
windows to customized, blast-
mitigating curtainwall, from historically
accurate replacements to sustainable-
designed, sun control systems.
Wausau Window and Wall Systems is a Registered Provider with The American Institute of Architects
Continuing Education Systems. Credit earned on completion of this program will be reported to CES
Records for AIA members. Certificates of Completion for non-AIA members available on request.

This program is registered with the AIA/CES for continuing

professional education. As such, it does not include content that
may be deemed or construed to be an approval or endorsement
by the AIA of any material of construction or any method or
manner of handling, using, distributing, or dealing in any material
or product.

Questions related to specific materials, methods, and services will

be addressed at the conclusion of this presentation.

© 2010 Apogee Wausau Group

 CURTAINWALL
Products, Performance and Practicality

Learning Objectives
1. Recognize and differentiate between different types of aluminum curtainwall.
2. Understand design parameters for curtainwall anchorage to the building, to ensure
ease of installation, movement accommodation, and structural integrity.
3. Optimize energy efficiency and thermal performance of curtainwall.
4. Learn how to mitigate blast hazards through curtainwall design.
5. Design for seismic movements and induced inertial loads.
6. Learn how curtainwall impacts building LEED® certification.
Section One

Curtainwall Types
 Curtainwall Types
In strictest architectural parlance, a
“curtainwall” is any non-load-bearing
exterior wall that hangs (like a curtain)
from the face of floor slabs, regardless of
construction or cladding material.
However, in common usage, the term
curtainwall usually refers to aluminum-
framed systems carrying glass, panels,
louvers, or occasionally, granite or marble.

Storefront Stick Wall The distinctions between the system types

discussed in the following slides are not
I-Beam Wall Pressure Wall absolute, and it’s often difficult to clearly
differentiate between one system type
Unitized Wall Window Wall
and another.

Face width sightline ranges from 2” to 4”;

system depth from 4 ½” to 10” or more.

Two-side structural silicone glazing can be

done in the field, however, four-side
silicone glazing should always be done
under factory-controlled conditions.
 Storefront
“Storefronts” are non-load-bearing
glazed systems that occur on the ground
floor, which typically include commercial
aluminum entrances. They are installed
between floor slabs, or between a floor
slab and building structure above.

Typically field-fabricated and glazed,

storefronts employ exterior glazing stops
at one side only. Provision for anchorage is
Glazed systems that occur on the made at perimeter conditions.
ground floor, and typically include
aluminum entrances. While sometimes used as a low-cost
alternative to curtainwall systems for low-
Installed between floor slabs, or rise buildings, performance requirements
between a floor slab and building for storefront are generally less stringent,
structure above and materials may require more frequent
maintenance.

Typical Performance:
Air less than 0.06 cfm per sqft at 1.57 psf
6 to 8 psf Water Test Pressure
 Stick Wall
“Stick” curtainwall systems are shipped
in pieces for field-fabrication and/or
assembly. These systems can be
furnished by the manufacturer as “stock
lengths” to be cut, machined, assembled,
and sealed in the field, or “knocked
down” parts pre-machined in the factory,
for field-assembly and -sealing only.

Shipped in pieces as: All stick curtainwalls are field-glazed.

Stock Lengths
-or- Frame assembly requires the use of
Knocked Down (KD) either, a) “shear blocks” to connect
vertical and horizontal framing elements,
or b) “screw-spline” construction, in
Shear
Block which assembly fasteners feed through
holes in interlocking vertical stacking
mullions into extruded races in
horizontals.

Typical Performance:
Air less than 0.06 cfm per sqft at 6.24 psf
8 to 10 psf Water Test Pressure
 I-Beam Walls Once very popular, “I-Beam” walls have
seen market penetration decrease.

“I” or “H” shaped, structural, vertical back

members are set into openings in the
field, with horizontals then clipped to
verticals.

Field assembled. Structurally- After glazing, extruded aluminum

efficient I-Beam vertical members. interior trim is cut and snapped into
place at vision areas. Since unexposed
Interior trim at vision areas. No finish spandrel areas receive no interior trim,
required at spandrel areas. savings in material and finish (painting
or anodizing) can result, partially offset
by added field labor.

Of course, maintaining vapor retardant

continuity at interior trim joints can be
challenging if any positive building
pressure is present.

Typical Performance:
Air less than 0.06 cfm per sqft at 6.24 psf
8 to 10 psf Water Test Pressure
 Pressure Walls Many stick curtainwalls are called
“pressure walls,” because exterior
extruded aluminum plates are screw-
applied to compress glass between
interior and exterior bedding gaskets. A
snap-on cover or “beauty cap” is then
used to conceal pressure plate fasteners.

Can be stick or factory-assembled. Performance of any field-assembled or

Field glazed using zone dams at field-glazed curtainwall is only as good
frame corners. as field workmanship allows, limited by
variables such as weather, access, and
Pressure plates and snap-on covers
job site dirt and dust. Many critical seals
at exterior, with joints allowing
are necessary, even in systems that are
thermal expansion.
designed to drain or “weep” rain
penetration from the system back to the
exterior.

“Compartmentalization” of each lite is

strongly recommended to isolate
glazing pockets.
Pressure
plate and Typical Performance:
snap-on
cover
Air less than 0.06 cfm per sqft at 6.24 psf
10 to 15 psf Water Test Pressure
 Unitized Walls
To accomplish as many critical seals as
possible in controlled factory conditions,
and minimize dependence on field labor,
“unitized” curtainwall systems have
been developed.

Unitized curtainwalls are factory-

assembled and -glazed, then shipped
to the job site in units that are typically
one lite wide by one floor tall.

Most unitized curtainwall systems are

installed in a sequential manner around
each floor level, moving from the
bottom to the top of the building.

Typical Performance:
Factory-assembled and factory–
Air less than 0.06 cfm per sqft at 6.24 psf
glazed under controlled conditions.
12 to 15 psf Water Test Pressure
Units are hung from the floor above
on pre-set anchors.
 Unitized Walls (continued)

Only one unit-to-unit splice, usually a

translucent silicone sheet or patch,
needs to be field-sealed. Seal bedding is
visible through the sheet.

Only one anchor per mullion needs to be

attached to the face of the floor slab.

Chicken The horizontal gutter weather-seal is

Head
sometimes called a “chicken head”
detail, due to its unique configuration.

Interlocking unitized curtainwall frame

members are weather-stripped to seal to
one another, both horizontally and
vertically. This accommodates thermal
expansion and contraction, inter-story
differential movement, concrete creep,
Only column foreshortening, and/or seismic
ONE movement.
field seal
 Unitized Walls (continued)
Product Selection Summary
 Window Wall “Window wall” systems span from the
top of one floor slab to the underside of
the slab above.

Head Window wall employs large, side-

starter &
two lines stacking window units, contained in
of
perimeter
head and sill receptors, also called
sealant “starters,” which accommodate
movement and drainage, but require
Slab field-applied perimeter sealants.
cover

Slab covers can be fabricated from

aluminum extrusions, sheet, panels, or
even glass.

Window walls easily accept operable

windows, and unlike curtainwall, can
easily be installed non-sequentially.
_________________________________

“Hybrid” systems combine

characteristics of multiple wall types.
For example, some four-side silicone
wall systems use stick wall grid frames,
with factory glazed carrier frames.
Section Two

Structural Design
Building Movements

Live load movements result from all

occupants, materials, equipment,
construction, or other elements of
weight supported in, on, or by structural
elements that are likely to move.

Live load movements can cause upward

or downward motion. For example, a
downward live load on a floor below can
Aluminum curtainwall is a result in disengagement of improperly
dynamic assembly designed curtainwall anchors on a floor
above that remains static, while resulting
in a “crushing” action at the floor below.

It is most helpful to quantify movements

separately in specifications; list live load,
column foreshortening, thermal, drift,
etc.
 ASCE7-08
Design Loads on Structures Buildings and their components are
designed to withstand code-specified
wind loads.
Calculating wind loads is important in
design of wind force-resisting system,
sliding, overturning, and uplift actions.
Wind loads are often quantified using
Based on 50-year mean American Society of Civil Engineers’
recurrence wind velocity “ASCE 7” publication and the
The eastern two-thirds of the U.S. is now in the 90 International Building Code.
mph contour. The leeward slope of mountains
are special wind regions. Determining wind loads is the job of the
building design team’s engineer of
record, not the window manufacturer.
Criteria should be listed on the first sheet
of the structural drawings.
Differing interpretation of corner zones,
insurer mandates, and local code
peculiarities could result in costly re-
Factors applied to basic velocity design if wind load determination is left
pressure formulae include: ambiguous in bid documents.
Gust effects, internal pressures,
building height, corner zones,
exposure, and partial enclosure
 Wind Load (continued)

Designed to withstand wind loads and

provide adequate glass edge flexural
support, curtainwall can be,

a) “simply supported,” with curtainwall

mullions anchored only at their ends;

b) “twin span,” with mullions spanning

For adequate glass support:
two floors and anchoring at the
Limit normal-to-wall deflections to L/175 intermediate floor or other structure; or
-or-
L/240+0.25” for spans greater than 13’-6”. c) “continuous span,” with the system’s
vertical mullions spliced at points of zero
moment (inflection points).

These are listed in order of increasing

structural efficiency, but before deciding
on an appropriate strategy, movements
and the ability of the structure to support
dead loads must be considered.
Wind Load (continued)
The ideal splice location is typically 20%
to 22% of span, occurring at the “zero
moment” point, where flexural stresses
reverse from compression to tension at
Ideal splice location is 20-22%
mullion flanges.
of span – Only shear loads
need to be transferred This can be important in locating interior
stools, interior finishes, shadow boxes, or
spandrel areas. The zero moment point
will be the most economical location for
the splice.
Designers need to be aware of the
maximum deflections for both vertical and
horizontal frame members. The typical
unit is hung from the top, therefore
drywall and other interior finishes only can
be attached in a manner allowing freedom
of vertical movement with the floor above,
and freedom of horizontal movement with
the upper unit mullion.
For tall “free span” atrium walls, be sure to
check additive deflections of glass,
horizontal members and vertical mullions.
Section Three

Anchorage
 Dead Load Anchors

Curtainwall anchorage must be

designed for each individual project’s
conditions, due to almost unlimited
combinations of loads, tolerances,
movements, and substrates. However,
there are basic anchor types and design
principles that are applicable to a wide
range of conditions.

Curtainwall anchor systems must carry

the dead load weight of the curtainwall.
This load is transferred from horizontal
framing members to vertical mullions,
and down to anchor points, where it is
transferred to the building structure.
Most curtainwall system dead
Wind loads primarily act normal to the
load weight is transferred to the
plane of the wall, acting in both inward
base, through vertical mullions.
(positive) and outward (negative)
directions.
Dead load can also be picked up
at intermediate floor slabs.
Standard Slab Anchors
In one standard anchorage method,
“double angle” mullion anchors
straddle both sides of the vertical
mullion, and are secured with a through-
bolt and pipe spacer.

The pipe spacer allows for vertical and

side-to-side building movement of
mullions, even when anchor bolts are
securely tightened.

The double angles are attached to the

face of the slab using insert weld plates,
channel-shaped embeds, or expansion
bolts drilled into the floor slab.

If embeds are used, it is recommended

that the curtainwall manufacturer supply
Three-way adjustment is critical. the embed layout drawings, to help
Can be bolted or welded in place. avoid excess coordination time and
costly errors.
Allow for movement by using pipe
spacers.
Jack Bolt Slab Anchors
One of the most economical ways to
anchor curtainwall is through the use of
manufacturer-specific, custom-designed,
three-way adjustable anchors.

These anchors allow for in-and-out, up-

and-down, as well as side-to-side
adjustment during installation, and feature
a “jack bolt” for fine vertical adjustment.

The jack bolt stops the movement of a

“saddle plate” attached to the side of the
mullion, thus allowing the hoist to unhook
and pick another unit, while the
curtainwall unit is being dropped into its
final position.

This saves field labor by utilizing hoist

“travel time” for concurrent, fine
Three-way adjustment is critical. adjustments.
Minimize time “on the rig” by
allowing manual fine-tuning to Jack bolt anchors can pre-set to the top-of-
level and plumb. slab or edge-of-slab.
 Anchor Design
Considerations If planning to field-drill into floor slabs or
other concrete structures, it is necessary
to consider where rebar or post-
tensioning cables are to be located. This
requires close coordination between
architectural and structural disciplines.
A building will move during the daily
temperature and use cycle. Care must be
taken in the design of the wall and its
anchorage to accommodate the full
range of movements.
The construction process is not one of
perfection. If the anchorage cannot
accommodate specified building
tolerances, time and money is lost.
In design, do not expect perfect visual
alignment, e.g. a ½-inch reveal that
Consider substrate strength and
varies +/- ½-inch can be rather
normal construction tolerances.
objectionable, but a 1-½-inch reveal that
Allow for movements. varies the same +/- ½-inch is more
visually forgiving.
Section Four

Energy Efficiency
 Thermal Performance
U-Factor
There are three basic thermal performance
parameters for wall systems. Expectations
for curtainwall performance are listed on
each of the following slides.

Thermal Transmittance: A measure of

heat flow per unit time, area and
temperature difference. U-Factor (or U-
Value) is expressed in inch-pound units as
U-Factor is used by the building BTU/hr.sqft.°F, and is the reciprocal of the
Mechanical Engineer for code more familiar R-value.
compliance, equipment sizing
and/or energy performance Don’t confuse center-of-glass (COG)
modeling. U-Values with overall system U-Factors
which includ edge-of-glass and framing
Prescriptive maximums are
effects.
given in Model Energy Codes
such as ASHRAE 90.1 and IECC.
For most cooling-mode-dominated
commercial buildings, U-Factor is the least
impactful thermal performance parameter.
Solar-Optical Performance
SHGC
Solar Heat Gain Coefficient (SHGC): A
dimensionless ratio of the total visible,
infrared and ultraviolet energy flowing
through glazing, divided by incident
energy.

Overall system SHGC is always less than

center-of-glass (COG) SHGC.

SHGC is affected by the shading

“Projection Factor” (PF) which is vision
glass setback or overhang depth; divided
by height, or PF = d/h
SHGC = Solar Heat Gain
Coefficient
For most cooling-mode-dominated
Prescriptive maximums are commercial buildings, SHGC is the most
given in Model Energy Codes impactful thermal performance parameter.
such as ASHRAE 90.1 and IECC.
State-of-the-art spectrally selective low-e
coatings can yield low SHGC with relatively
high Visible Light Transmission (VT) for
effective natural daylighting.
 Thermal Performance
CRF

Condensation Resistance Factor (CRF): A

dimensionless ratio of surface temperature
to ambient temperature difference.

CRF is useful in comparing design options,

but less useful in predicting field
CRF = Condensation Resistance condensation. Condensation is a local
Factor phenomenon, and average surface
Determined through surface temperatures are less important than “cold
temperature measurement in points”.
guarded hot box testing.
CRF is especially important in cold-climate
high-humidity applications such as high-
rise residential buildings, hotels, hospitals,
computer rooms, and kitchens.
 Thermal Performance
Finite Element Modeling

Finite element thermal modeling

software is widely used to predict thermal
performance of untested or custom
systems, or to estimate the performance of
specific frame-glass combinations.

Framing, edge of glass, and center of glass

performance is modeled, and such
modeling forms the basis of National
Fenestration Ratings Council (NFRC)
labeling programs, using public domain
software.
Modeling with DoE WINDOWS
The model shown illustrates the effects of
5.2 and FRAME 5.2 software is
interior “metal mass” on surface
the basis of NFRC energy
temperatures of a common curtainwall
labeling.
system. The exposed, interior aluminum
Guarded hot box testing is used improves CRF, but adversely impacts U-
to validate modeling results. Factor.
Solar-Optical Performance
Sun Control The use of aluminum sun shades is a
growing trend in architectural design on
buildings of all types. Just like any other
building design element, architects are
exercising their creativity with sun shades
using louvers, blades, catwalk grids, and
solid panels to accomplish their aesthetic
and daylight control goals.

In the most innovative designs, sun shades

are combined with interior light shelves
to control glare while maximizing daylight
penetration depth.

Sun shades present some engineering

Exterior sun shades are used to challenges in wind loading, snow loading,
block solar heat gain and ice build-up, and loads imparted by
increase Projection Factor (PF). maintenance operations.
Interior light shelves are used to
redirect visible light deeper into Close coordination of solar control
interior spaces with southern accessories with curtainwall manufacture
exposure. is critical to color match, continuity of line,
and structural integrity.
 Shadow Box Spandrels
Incorporating a shadow box into the
building design can give spandrel areas a
certain transparency. However, if not
properly designed and installed, shadow
boxes can create internal condensation
issues.

The shadow box’s air cavity must be

sealed nearly air tight relative to interior
Shadow box spandrels can add air in cold climates, since condensation
transparency to the wall. forms when moist warm air comes into
Be aware of heat build-up and internal contact with cold surfaces.
condensation risks. “Moire effect” with
certain silk-screened patterns. Recommendations for venting the shadow
box cavity vary with different applications
and locations

In all cases, the use of mineral wool

insulation is recommended because it
contains no organic materials, and is
resistant to the formation of mold and
mildew.
Section Five

Other Performance
Parameters
Other Performance Parameters
Acoustics
In addition to basic air, water, structural,
and thermal performance, certain sites and
occupancies require other characteristics.

When adjacent to highways, rail tracks,

airports, or other noise sources, acoustic
design of curtainwall systems is vital.

A typical curtainwall glazed with 1-inch

insulating glass exhibits a Sound
Transmission Class (STC) of 30 to 34.

Outdoor-Indoor Transmission Class (OITC)

is more appropriate for exterior wall
Use laminated glass to increase products. 1-inch insulating glass exhibits
acoustical damping, and avoid an OITC of 25 to 26.
resonance at high frequency.
If fairly air-tight and providing rigid glass
Acoustical Transmission Loss
support, frame type and design have little
(TL) is expressed in decibels
impact on STC or OITC, which are
(dBs), a logarithmic measure of
governed by glass type and air space.
sound pressure level difference.
 Other Performance Parameters
Blast Hazard Mitigation
Unfortunately, in many government and
institutional buildings, blast hazard
mitigation is a vital design criterion.

Always contact an experienced

manufacturer or blast consultant to
discuss design requirements. These
requirements are evolving as various
agencies fine-tune their standards.
Blast protection standards include the GSA
Inter-Agency Security Design Criteria (ISC) When curtainwall is exposed to the
and DoD Unified Facilities Criteria (UFC) UFC extreme pressures created by an
4-010-01 . explosion, all components of the assembly
System performance can be analytically work together. Modern blast-hazard-
determined, or tested in a shock tube or mitigating designs are intended to be
open arena facility. flexible and absorb blast energy.

Photos show inward-acting peak pressure

and outward rebound, in an open arena
test at 10 psi peak; 91 psi-msec impulse.
Other Performance Parameters
Seismic Design

Specifications for projects in many areas of

the U.S. dictate minimum movements
and/or clearances determined by analysis
of seismic design criteria. One such
criterion, “drift,” is the amount of inter-
story building movement anticipated
during a seismic event.
The structural grid assumes a
parallelogram shape, and glazing must
provide sufficient space between glass
and frame to ensure that contact does not
occur.
In the Table at left, “h” is story height.
Obviously, seismic movement can be
significant.
In California, seismic design of
hospitals must be approved by
the State OSHPD office, well in
advance of manufacture and
construction.
Other Performance Parameters
Seismic Design (continued)

What is the most important seismic design

criterion?
Early coordination with all
exterior wall components and Make sure curtainwall and surrounding
subcontractors is key to effective materials move at the same locations, or if
seismic movement not, that differential movements are
accommodation. considered in the design of the wall.

Remember that significant inertial forces

can be imparted by seismic movements.
Section Six

Sustainable Design
 Sustainable Design

Environmentally responsible, sustainable

building design and operation is a top-of-
mind issue for anyone in architecture,
construction, or real estate.

Buildings represent about one-third of the

energy consumption in the U.S., along
with the corresponding amount of
greenhouse gas emissions.

Since its inception in 2000, the voluntary,

consensus-based U.S. Green Building
Council LEED® (Leadership in Energy and
Environmental Design) Rating System™
Bren School of Environmental Sciences
has emerged as the leading sustainable
University of California at Santa Barbara
building “scorecard.”
LEED® Platinum
 The LEED® Scorecard
The LEED 3.0 scorecard tallies points in
seven credit categories:
Sustainable Sites (SS) – 26 pts.
Water Efficiency (WE) – 10 pts.
Energy and Atmosphere (EA) – 35 pts.
Materials and Resources (MR) – 14 pts.
Indoor Environmental Quality (EQ) – 15 pts.
Innovation in Design (ID) – 6 pts.
Regional Priority (RP) – 4 pts.

There are both environmental and

The USGBC LEED® system rates and financial benefits to earning LEED
certifies buildings, not building products certification. These include:
such as curtainwall. Lowering operating cost and increased asset value
Reducing waste sent to landfills
Up to 33 of the 110 total credits may be Conserving energy and water
affected directly by window and Increasing health and safety for occupants
curtainwall selections and design. Reducing harmful greenhouse gas emissions
Qualifying for tax rebates, zoning allowances and
other incentives in hundreds of cities
Demonstrating an owner’s commitment to
environmental stewardship and social
responsibility
 The LEED® Scorecard Combined with spectrally-selective high-
(continued)
performance low-e glass, the “right”
curtainwall for your building type and
climate zone is, by far, the most significant
opportunity to impact any building’s LEED®
rating.

Many manufacturers can provide

performance upgrade options presenting
leading-edge standard product options for
thermal transmittance (U-Factor) and Solar
Heat Gain Coefficient (SHGC).

Design for natural daylight harvest is the

ultimate “integrated design” activity, as
Energy and Atmosphere (EA)
many fenestration parameters affect
lighting, HVAC, and programmatic
Prescriptive building envelope outcomes.
requirements are based on ASHRAE 90.1
compliance for U-Factor and SHGC. Involve the entire design team early, and
keep coordinating as the design evolves.
Employ natural daylighting with artificial The use of Building Information Modeling
lighting controls to maximize benefits, as (BIM) design intent models can facilitate this
verified through whole-building energy cooperation.
modeling.
 The LEED® Scorecard
(continued)
The ultimate recycled material, the
Aluminum Association reports that:
Annual U.S. aluminum can consumption is 100
billion units, the equivalent of one per day for
each citizen.
It requires only 5% of the energy to recycle
aluminum as it does to smelt new aluminum.
Because of recycling, more than two-thirds of the
aluminum ever smelted is still in use.
Upon demolition, 90% of the aluminum in
Materials and Resources (MR) buildings is recycled.
One case of un-recycled aluminum cans wastes
the amount of energy in a gallon of gas.
For products, recycled and regional content On average, aluminum cans are back in use
are calculated based on weight of 60 days after recycling.
constituent materials. Separate reporting for The aluminum industry has cut carbon emissions
pre-consumer and post-consumer recycled by 53% in the last 15 years.
content is required. Most curtainwall manufacturers can provide
Glass represents about 70% of the weight of frame extrusions fabricated from secondary
a typical curtainwall assembly. billet. This material must be free of
contaminants, and can contain more than
For contribution to a building’s LEED® 40% “combined” recycled content, with no
points, recycled or regional content is minimum project size, and no impact on
proportioned by value, as defined by the finishing, cost, or lead times.
GC’s Schedule of Values.
 The LEED® Scorecard
(continued) Operable windows can be part of an
effective natural ventilation strategy, when
applied using the recommendations in the
Carbon Trust “Good Practice Guide
237”[1998] and ASHRAE 62.1-2004.
To achieve both Daylight and Views points,
the design must provide daylight and a view
to the outdoors for 90% of the regularly
occupied spaces. Ultra-clear glass is not
required.

EQ Credit 4.2 “Low-Emitting Materials –

Paints and Coatings” specifically exempts
factory baked-on finishes used on
curtainwall framing. Eco-friendly anodizing,
Indoor Environmental Quality (IEQ) powder painting and VOC-capture
incineration spray painting are all
Ventilation, Comfort and Control environmentally responsible processes.

Daylight and Views All primers, structural glazing adhesives, and

metal-to-metal sealants recommended for
Low-Emitting Materials use on-site must meet applicable SCAQMD
Rule #1168 VOC limits.
Section Seven

Summary
A Final Word… Selection and design criteria almost always
include:
Code Compliance
Structural Integrity
Weather-ability
Energy Efficiency
Condensation Resistance
Balanced Design Building Movements
Ventilation and Cleaning Access
Curtainwall selection Sustainable Design
and design should be Durability
based on all Cost
applicable criteria, not Aesthetics
on any specific single …and on some projects, also:
number rating system.
Emergency Egress
Hurricane Impact
Psychiatric Detention
Blast Hazard Mitigation
Noise Control
Seismic Movements
Smoke Evacuation

Consider all that apply to your project.

 CURTAINWALL
Products, Performance and Practicality

Learning Objectives Recap

1. Recognize and differentiate between different types of aluminum curtainwall.
2. Understand design parameters for curtainwall anchorage to the building, to ensure
ease of installation, movement accommodation, and structural integrity.
3. Optimize energy efficiency and thermal performance of curtainwall.
4. Learn how to mitigate blast hazards through curtainwall design.
5. Design for seismic movements and induced inertial loads.
6. Learn how curtainwall impacts building LEED® certification.
 For buildings using curtainwall systems as design elements, it is important to
consult with an experienced manufacturer early in the process. Teamed with a
reputable, local glazing subcontractor, manufacturers can provide design input,
budget pricing, sequencing, and schedule information that will prove
invaluable to the design team.

Nationally recognized for its innovative expertise, Wausau Window and Wall
Systems is an industry leader in engineering window and curtainwall systems
for commercial and institutional construction applications. For more than 50
years, Wausau has worked closely with architects, building owners and
contractors to realize their vision for aesthetic beauty, sustainability and lasting
value, while striving to maintain the highest level of customer service,
communication and overall satisfaction.

Learn more at http://www.wausauwindow.com or call toll-free 877-678-2983.

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