Changes to the latest editions of the model building codes have removed exemptions from fire testing for certain roof assemblies that previously were granted fire classifications without testing. If you are involved in the manufacturing, design, specification or installation of architectural metal panel, metal shingle, tile or slate roof systems, you should be aware of these revisions and the effects they may have on roof assembly designs.
The model building codes and most jurisdictions' codes historically have exempted certain roof covering types from fire testing and granted them fire classifications without testing. For example, the International Building Code,® 2006 Edition considered roof coverings of brick, masonry, slate, clay or concrete roof tile, exposed concrete decks, and ferrous or copper shingles or sheets to be Class A without fire testing. Similarly, roof coverings of other (nonferrous or copper) metal sheets and shingles were considered Class B without fire testing. At the time, the codes granted these roof coverings exemptions because they were thought to be inherently fire-resistant.