UL 580 roof panel rating...UL15, UL60, UL90, etc.

[hippo11]

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

 

[j19]

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.