Understanding who Factory Mutual (FM Global) is, what an FM wind uplift rating is, the testing involved to assign FM ratings and the differing rating requirements per the FM revision in 2006.
Factory Mission
Fly Missile
Factory Mutual
Fail Miserably
Insurance Company
Governing Code Body
Roofing Industry Association
Independent Product Testing Facility
Independent product testing facility
Governing code officials
Roofing industry association
FM's own in-house engineers
Cementitious wood fiberboard
24 Gauge Steel
22 Gauge Steel
Fiberglass reinforced plastic
Corners
Perimeter
Field Area
Ridge
2.0
1.15
2.15
3.0
3.0
1.15
2.15
2.0
5
10
15
20
Class 1 wind speed and 90 lbs psf of actual field of roof wind uplift pressure
Class 1 wind speed and 45 lbs psf of actual field of roof wind uplift pressure
Class 1 interior fire classification and 90 lbs psf of actual field of roof wind uplift pressure
Class 1 interior fire classification and 45 lbs psf of actual field of roof wind uplift pressure
FM 1-60
FM 1-90
FM 1-75
FM 1-105
FM 1-150 (perimeter) and FM 1-225 (corners)
FM 1-195 (perimeter) and FM 1-295 (corners)
FM 1-225 (perimeter) and FM 1-330 (corners)
FM 1-255 (perimeter) and FM 1-360 (corners)
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