Fm Global Roof Ratings

Fm global wind ratings explination.

Fm global roof ratings.

Flashing details should be in compliance with data sheet 1 49 perimeter flashing. Fm approvals is the only organization in the world that tests complete roof assemblies when subjected to multiple perils such as fire testing above and below the deck wind uplift testing hail damage testing accelerated weathering water leakage foot traffic and corrosion resistance testing of metal parts. In this situation the fm regional engineer specifies that the roof must have a wind rating such as 1 60 1 75 or 1 90. Successful constructions over steel roof decks are designated by fm global as class 1.

This may be all that is specified. Situation is i speced a roof customer emailed last night asking wind rating i spent hours trying to figure that out after hours. The research is also used to enhance external standards. Fm global conducts research for use in the fm global data sheets that our engineering field staff use to support our client s efforts to protect their business.

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. I m finding it much simpler just to use the manufacturer wind warranty options than screwing with all this fm stuff. Fm global uses a furnace calorimeter that measures heat released by the test specimen with no more than 400 btu per minute released during the steepest three minutes of the temperature curve. 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.

The perimeter flashing for roofs should be fm approved and have a minimum wind uplift rating of 105 for the high roof and 75 for the low roof. Designed to help roofing professionals roofnav provides easy access to the most up to date fm approved roofing related information and related installation recommendations from relevant fm global property. Provide perimeter and flashing details to fm global for review. This may be all that is specified.

A roof assembly is tested to meet. 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. Fm wind rating specified only. Technical reports supporting code change.