FM disagrees with article | Letters
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
addresses.
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
Uplift Tests."
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
7-05 requirements...
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