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3.09
WIND
LOADING
Notes
1. Values are nominal design 3-second gust wind speeds in miles per hour (m/s) at 33 ft. (10m) above ground for Exposure C category.
2. Linear interpolation between wind contours is permitted.
3. Islands and coastal areas outside the last contour shall use the last wind speed contour of the coastal area.
4. Mountainous terrain, gorges, ocean promontories, and special wind regions shall be examined for unusual wind conditions.
5. Regions outside the contiguous 48 states - refer to ASCE
7 or your local building official.
Determining the correct wind loads on individual structures can be very complicated, and it is important
to have a firm understanding of the way that a structure resists the wind. The following is a partial listing
of the factors that may have an influence on the wind loads used for the design of a truss:
• Geographic location of the building (to determine the basic wind speed, see "Basic Wind
Speed Map")
• Height above ground
• Exposure category of terrain around the building being designed
• Building use
• Location of truss in building
• Location of building in relation to hills and escarpments
• Building dimensions
• Area of load carried by the truss
• Building porosity (open, closed or partially open)
• Dead load on the trusses to be considered for wind analysis (usually
less than the gravity design dead load).
Wind Load Factors
ENGINEERED BY ALPINE
S P E C I F Y I N G / D E S I G N I N G
