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Wind load
1. Wind Load Technical Information
(A Dis-Gust-Ing Subject?)
Joe Hetzel
Technical Director
Door & Access Systems Manufacturers Association
2. DASMA’s Mission:
• “DASMA, acting through the united efforts
of its members, is the industry’s voice for
regulatory, technical and product issues
affecting market growth, safety and
acceptance of the product categories
manufactured by member companies.”
3. Overview Of Our Seminar
• What?
• Who cares?
• Where do we even need it?
• Why should we even bother with this?
• “Tech” Time!
• Photos – What the wind left behind….
• Resources for you
4. People Are Saying….
• “…garage doors performed relatively well
in the 2004 Florida hurricanes…”
• “…garage door performance has improved
in the last ten years…”
• Current lists of building products of high
concern have NOT included garage doors
• DASMA Wind Load Technical Information
Is Helping Make A Difference!
5. What?
• TDS-152, Garage Doors And Hurricanes
• TDS-153, Vertically Reinforced Garage
Doors
• TDS-155, DASMA Wind Load Guides
• TDS-161, Connecting Garage Door Jambs
to Building Framing
• TDS-168, Frequently Asked Questions
6. Who Cares?
• Building owners and homeowners do!
• Insurers do!
• Essential services personnel do!
• Code officials do!
• Design professionals do!
• We as an industry do, too!
7. Where do we even need it?
• Everybody knows about Florida…but how
about
• The Gulf Coast
• The Atlantic seaboard
• North Carolina
• Kansas City (huh?)
• Be on the lookout for your area
8. Why should we even bother with this?
To strengthen the chain links!
1. Code content
2. Code adoption
3. Code enforcement
4. Product specification
5. Product integrity
6. Product installation
9. Link #1 – Code Content
• “Model” Building Codes
• Technical Research
• DASMA Influence
10. Link #2 – Code Adoption
• State And Local Levels
• More Politics!
• Which Code?
• Which Amendments?
11. Link #3 – Code Enforcement
• Local level
• Blend of technical and political
• Plan reviews; site inspections
• Common problem: Technical misunderstandings
• Appeals process
12. Link #4 – Product Specification
• Knowing the applicable job conditions,
along with the correct code interpretation
• Knowing the available product selection
and selecting the right product
• Recent examples
– Essential facilities
– Metal buildings
13. Link #5 – Product Integrity
• Suitability (Material Choices)
• Quality (Control; Assurance)
• Strength (Testing)
• DASMA standards
– ANSI/DASMA 108; ANSI/DASMA 115
• Other standards
– ASTM E 330; Miami-Dade TAS 201/202/203
16. TDS-152, Garage Doors And Hurricanes
• Don’t back car against door
• Close the door before a hurricane
• Homeowner should not add weight to the
door
• Know if “breakaway” construction
supersedes wind load requirement
• Have a professional evaluate the door
17. TDS-153, Vertically Reinforced Garage Doors
• General
– Comply with industry standards
– Test to wind standards
• Types
– Integrated into door design
– Supplied with door by manufacturer
– Aftermarket product
18. TDS-161,
Connecting Garage Door Jambs to Building Framing
• 8 different fastener types
• Charts show maximum spacing
• Variables:
– Door Width
– Design Load
– Jamb Materials
19. TDS-168, Frequently Asked Questions
• Does orientation of the door on the building affect
load?
• Does direction the door faces affect load?
• Does house layout configuration affect load?
• Why can’t the industry just supply a “100 MPH
door”?
• Why do people ask questions? (Not included)
20. TDS-155, Wind Load Guides
• Cover sheet
• Codes old and new (current codes are 2003
IBC and 2003 IRC)
• Standards old and new (current standard is
ASCE 7-02)
21. Wind Fundamentals
• Inward and Outward Loads
• Normal to Surface
• Loads Influenced By:
– Geographic Location
– Exposure Condition
– Building Importance
– Opening Size
– Opening Protection
– Building Configuration
– Door Location
22. Wind Load Variables
• Building height above finished grade
• Design wind speed
• Exposure category
• Garage door horizontal location
• Product designation
• Use factor
• Building Type, with respect to openings
• Roof Pitch
• Door Area
23. DASMA “Wind Load Guides”
• Based on ASCE 7 and the IBC
• In process of referencing ASCE 7-02
(equivalent to ASCE 7-98)
• In process of reference the 2003 IBC
(equivalent to the 2000 IBC)
• Commercial and Residential Guides
• Guides based on Exposures B, C and D
24. Building Height Above Finished
Grade
• ASCE 7-98 Section 6.5.12.4.1
• IBC Section 1609.6 (“Simplified Wind
Load Method”)
• Buildings less than 60 feet in height (“Low-
Rise Buildings)
• Guides use building heights of 15’ and 25’
25. Design Wind Speed
• ASCE 7-98 Figure 6-1
• IBC Figure 1609
• Guides based on 90-150 MPH
• Three Second Gust values
26. Exposure Categories
• ASCE 7-98 Section 6.5.6.1
• IBC Section 1609.4
• Exposure B: Typical Residential
Subdivision; Wooded Areas
• Exposure C: Open Terrain; Hurricane-
Prone Shorelines
• Exposure D: Within 1/4 Mile of an Inland
Lake at least One Mile Across
27. Garage Door Horizontal Location
• ASCE 7-98 Figure 6-5A
• IBC Section 1609.6.3
• Smaller of 10% of least horiz. dim. (use
40’) or 40% of eave height (use >10’): 4 ft.
• Not less than the larger of 4% of the least
horiz. dim. (use 40’) or 3’; 3 ft.
• Guides use 4 ft.; 2 ft. of which extend onto
the garage door surface
28. Product Design Designation
• ASCE 7-98 Section 6.2
• IBC Section 1609.2
• Main Wind-Force Resisting System: An
assemblage of structural elements assigned to
provide support and stability for the overall
structure.
• Components and Cladding: Elements that do not
qualify as part of the MWFRS.
• Guides based on garage doors as Components
and Cladding
29. Importance Factor
• ASCE 7-98 Table 6-1
• IBC Table 1604.5
• Guides based on Category II factor
• Applies to non-essential structures, and
structures with no substantial hazard to
human life in the event of failure
30. Building Type
• ASCE 7-98 Section 6.2
• IBC Section 1609.2
• Partially Enclosed Building:
– Openings in a wall > Openings in the balance of the
building envelope by more than 10%
– Openings in this wall > 4 SF or > 1% of wall area
– Openings in the balance of the building <20%
• ASCE 7-98 Figure 6-5A
• Guides apply to Enclosed Buildings
31. What’s An Opening?
• ASCE 7-98 Section 6.2
• Not in the IBC
• Apertures or holes in the building envelope
• Which allow air to flow through the
building envelope
• And which are designed as “open” during
design winds
32. Roof Pitch
• ASCE 7-98 Figure 6-5A
• IBC Figure 1609.6(2)
• 10% coefficient reduction if roof pitch is less than 10
degrees (“low-slope”)
• Guides: “Low-slope” roof systems are treated as
commercial structures
• IBC “Simplified” Table 1609.6.2.1(2) does not include
reduction option
• Guides include both residential and commercial structures
34. The Guides - Explained
• Geographic Location
• Design Wind Speed
• Exposure Category
• Structure Use
• Structure Height
• Garage Door Width
35. The Guides - Example
• Charleston, SC
• IBC (based on ASCE 7-98)
• 130 MPH design wind speed, Exposure B
• Residential structure
• Double story house (25’ mean roof ht.)
• Double garage door (16’ x 7’)
Calculated Wind Load:
• 25.9 PSF (positive wind load)
• -28.8 PSF (negative wind load)
36. Garage Door Wind Load Comparisons
130 MPH Design Wind Speed
Exposure/Size 9’ x 7’ 16’ x 7’
B +26.9 -30.8 +25.9 -28.8
C +36.3 -41.6 +35.0 -38.9
D +43.3 -49.6 +41.7 -46.4
Exposure/Size 9’ x 7’ 16’ x 7’
B +26.9 -30.8 +25.9 -28.8
C +32.5 -37.3 +31.3 -34.8
D +39.5 -45.3 +38.1 -42.3
One-Story House:
Two-Story House:
37. The Guides - Exceptions
• Another code or standard used
• Garage doors with > 2 ft. in end zone(s)
• Local enforcement requires higher loads
• Special retrofit situations
• Partially enclosed and open structures
• Essential facilities/hazardous buildings.
53. Possible Coming Attractions!
• Post-high wind event door inspection
guidelines for dealers!
• Post-high wind event door operation
guidelines for building occupants!
• New and improved technical coordination
with doors on metal buildings!
• DASMA web site wind calculator!
54. When You Need Technical Information, …
• DO go to the web www.dasma.com
• DO E-mail us Jhetzel@dasma.com
• DO fax us 216-241-0105
• DO call us 216-241-7333
• DO get our magazine (Door & Access Systems)
• DO talk to your product supplier
• DON’T…hesitate!
