Fire Resistance of Natural Slate Roofing

Burning brand test in progress.

Fire Resistance Testing of Natural Slate Roofing

The National Slate Association (NSA) and National Roofing Contractors Association (NRCA) recently teamed-up to conduct testing of the fire resistance of a slate roofing system in accordance with UL 790, “Standard Test Methods for Fire Tests of Roof Coverings.”

The testing was inspired by a modification in the International Building Code (IBC), the 2009 edition of which identifies slate roof covering assemblies as having a Class A fire resistance just when mounted over a fireproof roof deck. Previous editions of the IBC marked slate roofing treatments as having a Class A rating when set up over combustible and also fireproof roofing system decks. The examination setting up included nominal 1/4-inch thick, North American slate roof shingles laid with a 3-inch headlap over No. 30 felt underlayment on a 1/2-inch plyboard roofing system deck. The examined assembly attained a Class A ranking.

While it is really hoped the positive test outcomes can be utilized to substantiate the fire resistance of likewise created slate roof covering assemblies, NSA as well as NRCA will remain to interact to excluded slate roofing system coverings from examining to establish their fire classification in future editions of the IBC. For questions connected to these examination records, please consult with the National Slate Organization toll free at 866-256-2111 or email them.

These photos are property of Mark_S_Graham, see additional photos on Flickr.