USG Exterior Ceiling Applications Systems Guide - Manual (Page 5)

4 USG Exterior Ceiling Applications
Wind Design Notes Miles per hour (MPH) versus pounds per square foot (PSF)
ASCE 7-10, Minimum Design Loads for Buildings and Other Structures, American Society of Civil Engineers/
Structural Engineering Institute (ASCE/SEI), contains a formula that converts wind speed into static pressure.
The formula is a comprehensive approach to include factors such as height or location of the building, or
directionality of wind loads affecting the structure expressed as:
q
z
= 0.00256 K
z
K
z t
K
d
V 2
q
z
= velocity pressure evaluated at height z above the ground
K
z
= velocity pressure exposure coefficient
K
z t
= topographic factor
K
d
= wind directionality factor
V = basic wind speed
The approximate value of wind pressure (PSF) can be calculated without knowing all of the factors described
above by utilizing the simplified formula shown below.
p = 0.00256 V 2
p is the pressure (measured in psf)
V is the wind speed (measured in mph)
Wind load provisions of ASCE 7-10, are recognized in the 2012 International Residential Code (IRC) and the
2012 International Building Code (IBC). The information presented is correct to the best of our knowledge at the
date of issuance. Because codes continue to evolve, check with a local official prior to designing and installing a
ceiling system. Other restrictions and exemptions may apply.
System Overview
USG Exterior Ceiling Applications
Note: All systems shall comply with local wind load requirements. The engineer of record shall determine the final
recommendation for the design wind pressure