ul 580 roof panel rating...ul15, ul60, ul90, etc

huangyhg

ul 580 roof panel rating...ul15, ul60, ul90, etc.
i got a question from an architect on what rating the roof panel needs to achieve in the ul 580 test.  the arch is writing his specs for a particular project.  any thoughts?  should they specify fm 4474 ratings instead?  when do you use fm and when ul?
thanks
most architects specify a class 90 rating.  
assuming that the architect is going to use a standing seam roof system over open framing (i.e. not a composite system with metal roof over rigid board insulation and metal deck), fm 4471 (not fm 4474) provides a better evaluation of how the roof system will perform under uplift wind loads.  actually, astm e 1592 seems to be the current "state-of-the-art" method for testing standing seam panels.  this test method is required by aisi (naspec) and all major manufacturers should be able to supply you with their allowable design values.