Fm Roof Uplift Ratings

Understanding wind uplift ratings for roofing.

Fm roof uplift ratings.

We would like to show you a description here but the site won t allow us. Fm approvals have classification ratings 1 60 1 90 or 1 120. Include drawings and details of the roof cover flashing and design loads. The insurance industry and in particular factory mutual research corp.

The misconception is that these numbers correlate to wind speeds of 60 90 or 120 miles per hour. Designed to help roofing professionals roofnav provides easy access to all roofing related information from the fm approvals approval guide and related installation recommendations from relevant fm global. Take the guesswork out of an fm approved roof roofnav can take the guesswork out of configuring an fm approved roofing system leaving you to focus on what matters most. Fmrc the primary entity in the united states testing and approving roof assemblies with ratings related to wind uplift fire and hail resistivity.

In the case of roofing systems fm is particularly well known for determining how roofing performs not only for fire but also for high wind. These ratings actually apply to wind uplift pressure in pounds per square foot and are not directly related to wind speeds. The following information is needed to conduct a thorough review of new roof installations and re roofing projects. Square foot of uplift force in the field of the roof.

Roofnav is a complimentary tool from fm approvals that provides access to the most up to date fm approved roofing products and assemblies. With extreme wind events on the rise now is the time to. In fact it is unique among other testing laboratories in the way that it performs wind uplift testing it uses full scale roof sections measuring 12 feet by 24 feet to obtain an accurate view of. Designed to help roofing professionals roofnav provides easy access to the most up to date fm approved roofing related information and related installation.

Let s assume that the calculations for our building require a roof that can withstand 23 pounds per square foot of uplift force in the field of the roof. Fmrc became the default specification for wind uplift criteria whether the building was insured by fmrc or not. Roof projects new fm global reviews roof plans to determine resistance to anticipated wind uplift pressures and fire spread potential. Windstorm classification rating misconception.

Because fm approvals requires a 2 1 safety factor roofs with field of roof uplift forces of 30 pounds per square foot are the maximum for 1 60 ratings and 37 5 pounds per square foot are the maximum for 1 75 ratings etc. Mark gallant jun 22 2020.