NRCA and the National Slate Association (NSA) recently conducted limited fire testing of slate roof systems. If you supply, design or install slate roof systems, I encourage you to be aware of the building code-related circumstances that necessitate this work and the test results.
In the International Building Code, 2009 Edition (IBC 2009), an exception from fire testing in the code's previous editions was removed. The exception waived slate roofs from fire testing to determine their fire classifications. With IBC 2009, newly installed slate roof systems installed on combustible roof decks need to be tested and have a listing of their fire classifications. For additional information, see "New fire classifications," April issue, page 24.