Wind Design Calculator

This Wind Design Calculator is used to calculate the roof edge design pressure. All versions of International Building Code since 2003 have required per Section 1504.5 that metal edge systems, except gutters, be tested per ANSI/SPRI ES-1 or ANSI/SPRI/FM 4435/ES-1 to resist wind loads in accordance with Chapter 16. The 2021 version of IBC will also require some gutters to be tested per ANSI/SPRI GT-1. This calculator is based on ASCE 7 as prescribed by IBC Chapter 16, and can be used to calculate the design loads that edge metal systems must be tested to resist.

The calculator requires four inputs: 1. Project location (zip code), 2. Building height, 3. Exposure, 4. Importance Classification (Risk Category). Project name is optional as a reference for the user. Based on the zip code location the calculator will select the appropriate wind speed and version of ASCE 7 required; however, those can be changed by the used if desired.

NOTE: The P Design Pressure results in bold below are for Edge Metal in corner zones (zone 3 for vertical, and zone 5 for horizontal) of an enclosed building and include a 2.0 safety factor.  Edge Metal pressures at perimeter zones will be lower.  Adjustment may be required for partially enclosed buildings or a different safety factor.  The velocity, roof, and wall pressures below are provided for reference and do not include a safety factor.

Wind Calculator
Surface Roughness/Exposure B
Urban and suburban areas, wooded areas, or other terrain with numerous closely spaced obstructions having the size of single-family dwellings or larger.
Surface Roughness/Exposure C
Open terrain with scattered obstructions having heights generally less than 30 ft. (9.1 m). This category includes flat open country and grasslands.
Surface Roughness/Exposure D
Flat, unobstructed areas and water surfaces. This category includes smooth mud flats, salt flats, and unbroken ice.
For information about the Importance Classifications/Risk Category, please click here to review the risk category documentation (will open in a new tab/window)