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.
Fm global roof ratings.
Successful constructions over steel roof decks are designated by fm global as class 1.
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.
I m finding it much simpler just to use the manufacturer wind warranty options than screwing with all this fm stuff.
Flashing details should be in compliance with data sheet 1 49 perimeter flashing.
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.
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 expected real world performance.
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.
A roof assembly is tested to meet.
Roofnav can take the guesswork out of configuring an fm approved roofing system leaving you to focus on what matters most.
This may be all that is specified.
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.
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.
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.
This may be all that is specified.
Fm global wind ratings explination.
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.
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.
Provide perimeter and flashing details to fm global for review.
Fm wind rating specified only.
