In your March issue, the article "Understanding wind-resistant design," page 43, by Mark
S. Graham, NRCA's associate executive director of technical
services, makes several good points, including that a safety factor
of 2.0 is appropriate for wind design of roof systems.
However, I would like to clarify some points the article
First, the article does not reflect the most recent changes and
enhancements published in the February 2007 version of FM 1-29,
"Roof Deck Securement and Above-Deck Roof Components." The updated
data sheet is available at no cost at www.roofnav.com along
with updates to FM 1-28, "Design Wind Loads," and FM 1-52, "Field
Second, the article states FM Global recommends design wind
loads up to 49 percent greater than those stated in ASCE 7-05,
"Minimum Design Loads for Buildings and Other Structures." In fact,
FM Global recommendations are at most 15 percent higher than ASCE
To read the article in its entirety, please log in or register (registration is free).
Log in or register for FREE access to this article and other Professional Roofing online content.