1. WELCOME!
CES Course 000104
Designing for Impact
2. 104 Designing for Impact
“Designing for Impact”
Weather Shield’s Continuing Education Program for Architects
AIA Course Reference: WS101
This course qualifies for 1.0 LU AIA/CES credits
3. 104 Designing for Impact
Weather Shield was founded in 1955 and is family owned.
Weather Shield Windows and Doors is one of the nation’s
leading window and door manufacturers.
LifeGuard® is a complete line of code-approved impact-
resistant windows and doors providing lasting beauty,
superior energy performance and sound control while
reducing the likelihood of wind-borne damage
4. 104 Designing for Impact
Weather Shield Mfg., Inc. 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.
Thank you!
5. 104 Designing for Impact
Our Learning Objectives Today
1. You will have a basic understanding of wind
load requirements and Design Pressure (DP)
ratings for windows and doors
2. You will understand the basic wind-borne debris
code requirements for impact-resistant windows
and doors
3. You will learn about the various applications
and specifications for impact-resistant windows
and doors
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Top Ten Most Destructive Hurricanes (Atlantic)
Note: damages are listed in U.S. Dollars and are not adjusted for inflation
Source: www.mthhurricane.com
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The Dynamics of a Hurricane
• High velocity winds create flying debris acting as
shooting missiles
• Flying debris breaks through windows or doors allowing
pressure to build up inside the structure
• Rapid changes in both negative and positive wind pressures
can cause severe structural damage
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The Ongoing Threat of Destructive Hurricanes
Causes Code Change
• High Design Pressure (DP Rating) required for windows
and doors
• Wind-borne debris protection becomes mandated in specific
regions for all openings (windows and doors)
• Cyclical pressure test to simulate the negative and positive
pressures of a hurricane
• Energy efficiency
requirements as
wind-borne debris
codes move north
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SECTION ONE
Understanding wind load requirements
and Design Pressure ratings for
windows and doors
This section will review the basic wind load
requirements and Design Pressure (DP) ratings for
windows and doors in hurricane-prone regions
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Wind Loads
• The first item that must be established is the wind load rating
of the building or structure
• The basic wind speed maps from ASCE-7 can help determine
the proper wind speed delineation zones for a specific area
• There are special requirements for buildings sited in areas
called “wind-borne debris regions,” defined as areas along
the Atlantic and Gulf coasts where the design wind speed is
120 mph or above
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Florida Wind Speed Map
www.floridabuilding.org
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Design Loads
• Represents wind load pressure
for which the product is designed
• Incorporates a safety factor;
testing 150% of design pressure
(DP50 is tested at 75 PSF)
• Positive and negative design
pressure requirements for
wind-borne debris regions
• Water performance must meet
the positive pressure required for
structural design
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Determining Design Loads
1. Wind Speed Zone 2. Exposure Classification 3. Building Importance
4. Mean Roof Height 5. Unit Size 6. Wall Location
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Wind-Borne Debris Requirements
• After determining the design load, the next requirement for
the coastal area is to determine the proper wind-borne
debris protection
• Windows and doors designed for
wind-borne debris regions will have
the following characteristics
– High design loads
– Missile impact approval
– Cyclical pressure test for
specific design pressures
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SECTION TWO
Understanding the different wind-borne
debris code requirements for impact-
resistant windows and doors
This section will review the basic wind-borne debris
codes and performance requirements for windows
and doors in wind-borne debris regions
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Key Building Codes
• International Building Code (IBC)
for commercial construction
• International Residential Code (IRC)
for residential construction
• Florida Building Code (FBC)
for all construction in the state of Florida
www.iccsafe.com www.floridabuilding.org
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Wind-Borne Debris Standards
• The IRC and IBC have provisions for wind-borne
debris standards
• The standard test method and specifications reference
ASTM E 1886 and ASTM E 1996 for large missile impact
and cyclic pressure loading
• Various approval and state agencies have adopted the
wind-borne debris standards such as Texas Department
of Insurance, Miami-Dade, State of Florida, WDMA
and AAMA
TDI
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Wind-Borne Debris Standards
• Wind-borne debris requirements are defined by missile level
and wind zone (building height and location)
• Wind-borne debris requirements are only applicable where
mandated by local or regional building codes
• It is up to the architect to determine the right product
performance and code approval for the project
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Wind-Borne Debris Options
Glazed openings must be protected
1. Impact-resistant panels
2. Impact-resistant shutters
3. Impact-resistant glazing system
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Wind Zones and Missile Types
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Impact Missile Requirements
Missile Missile Impact Speed Typical Use
Level feet/sec (mph)
A 2 gram steel ball 130 (89) Above 30 ft.
Wind Zone 1 through 4
B 2 lb. Lumber 50 (34) Skylights < 30 ft.
Wind Zone 2 (Basic)
C 4.5 lb. Lumber 40 (27) Less than 30 ft.
Wind Zone 1 and 2 (Basic)
D 9 lb. Lumber 50 (34) Less than 30 ft.
Wind Zone 3 and 4 (Basic)
Wind Zone 1 and 2 (Enhanced)
E 9 lb. Lumber 80 (55) Less than 30 ft.
Wind Zone 3 and 4 (Enhanced)
Wind Zone 1 – 110mph
Wind Zone 2 – 120mph
Wind Zone 3 – 130mph
Wind Zone 4 – 140mph
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Cyclical Pressure Testing
• Designed to simulate the positive
and negative pressures caused
by a hurricane
• Determines the maximum positive
and negative design pressures of
each approved window and
door system
• 9,000 total cycles with 3 seconds
per cycle of design pressure
• Cycling occurs after impact
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Cyclic Static Air Pressure Loading
9,000 total
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Product Approvals
APPROVAL CHECKLIST
• Request a copy of the approval
• Make sure the product is approved
for impact
• Check size and design pressures
• Make sure it meets the proper
impact requirement
(large versus small)
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Example Design Pressure Calculation
1. Unit installed in Zone 5 of structure
2. Mean roof height of 30’
3. Window product is 3’ x 4’ = 12 square feet
4. Home located in wind zone of 140 mph
Positive and negative design pressures of +33.7/–36.7 based
on Table R301.2(2) calculated for Exposure B
5. Home located in exposure “C” requires adjustment
coefficient of 1.40 in accordance with Table R301.2(2)
+33.7 x 1.40 = +47.18 (positive design pressure)
-36.7 x 1.40 = -51.38 (negative design pressure)
Design Pressure required is +47.2/-51.4
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SECTION THREE
Understanding the various applications
and specifications for impact-resistant
windows and doors
This section will review the design options and
specifications for impact windows and doors based
on building codes, applications and installation
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Product Options
Active Glazing Options
• Plywood that meets code specifications
• Code-approved screens
• Code-approved storm panels
• Code-approved shutters
Passive Glazing Options
• Code-approved impact-resistant
windows and doors
– Wood
– Aluminum Clad
– Aluminum
– Vinyl
– Fiberglass
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Product Limitations
Aluminum and aluminum clad (wood) impact-resistant windows
typically give designers the greatest selection in size, options and
design pressures offering the largest glazed openings and the
highest design pressures
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Window and Door Sizing
Example: Manufacturer’s Sizing Charts
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Critical Design Elements
• Physical location of structure
• Type of windows/doors (wood, aluminum, vinyl)
• Overall window/door size
• Missile approval (large or small)
• Design pressures (to meet local requirements)
• Product code approval
meets project specifications
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Proper Installation is Critical
High DP ratings and impact-resistant products may require specific
installation (often more in-depth than standard product installation)
• 1/4” maximum shim space
• Additional anchoring through nailing fins
• Different anchoring method (i.e., screws instead of nails)
• Longer anchors
• Use of installation brackets
• Installing anchors through
sash/frame into the openings
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Certified Installation Methods
Products tested in accordance with American Architectural
Manufacturers Association (AAMA) have certified methods of
installation noted in body of test reports
Installation which differs from the certified details will not assure
similar product performance and will not be accepted in areas
requiring specific design pressure ratings
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Example of Installation for
High Performance Product
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Installation for Impact-Resistant Window
Example: Manufacturer’s Installation Specifications
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Energy Efficiency
• As mandated codes for wind-borne debris requirements
moves north, the demand for energy-efficient impact-resistant
windows and doors will increase
• Most impact-resistant windows and doors use monolithic
laminated glass offering great impact-resistance but poor
insulation or energy efficiency
• There are code-approved products that use insulated Low E
glass offering energy efficiency – look for impact-resistant
windows and doors with the Energy Star seal
39. 104 Designing for Impact
Energy-Efficient Windows
40. 104 Designing for Impact
SUMMARY – SECTION ONE
Understanding the wind load
requirements and DP ratings for
windows and doors
• Wind loads are critical and are determined from wind speed
maps (ASCE-7)
• Design loads represent wind load pressures for window and
door products
• Design loads take in consideration six critical elements
Wind speed, exposure classification, building importance, roof height,
window/door unit size and location on the building
41. 104 Designing for Impact
SUMMARY – SECTION TWO
Understanding the different code
requirements for impact-resistant
windows and doors
• The IBC and IRC are national building codes that provide
standards for wind-borne debris regions
• Various governing bodies and agencies adopt the recognized
standards and enforce the approval process
• There are various impact requirements depending on
geography, window/door placement and building type
42. 104 Designing for Impact
SUMMARY – SECTION THREE
Understanding the various applications
and specifications for impact-resistant
windows and doors
• There are two general categories of glazing protection:
Active systems and Passive systems
• It is critical to make sure the code-approved products
specified meet the required wind-borne debris specifications
• Proper installation of code-approved windows and doors is a
must to provide the level of performance the systems have
been tested to
43. 104 Designing for Impact
Review of Learning Objectives
1. You will have a basic understanding of wind
load requirements and Design Pressure (DP)
ratings for windows and doors
2. You will understand the basic wind-borne debris
code requirements for impact-resistant windows
and doors
3. You will learn about the various applications
and specifications for impact-resistant windows
and doors
45. THANK YOU!
This concludes the American Institute
of Architects Continuing Education
System Program
Please contact your Weather Shield
representative for additional information
www.weathershield.com