United Roofing's Blog

Fire Ratings and Your Roof

Fire Resistance Ratings In fact, the materials that you use for your roof must be fire resistant and have a rating to let you know how much safety and protection the roof will provide. Regardless of the type of roof you choose to have installed, it is important to understand fire resistance ratings and choose your roof according to the desired rating you prefer. Fire Ratings for Roofing Material The independent, for-profit company Underwriters Laboratories Inc (UL) has developed a series of laboratory tests to measure how well roofing materials (such as shingles) resist fires. These tests are widely accepted by the roofing industry, and the results are widely quoted in industry promotional materials. UL 790, the most widely quoted standard, tests roofing materials’ resistance to fires from external sources — fires that originate outside of the house (such as from a lightning strike). It should be noted that the fire rating is not earned solely by the physical properties of the roofing material, but also by installing the material in the manner recommended by the manufacturer. The UL assigns roof coverings a rating that ranges from Class A (the highest level of protection) to Class C (the lowest level of protection). There are three fire resistance ratings — Class A, Class B, and Class C. Class A offers the highest protection from fire while Class C offers the least amount of protection. A roofing material that receives a Class A, B or C rating should maintain its position on the roof following a fire, and is not expected to generate flying, burning, shards of shingle. Class A roof...