What You Need to Know About Roof Fire Ratings

When getting a new roof, color, material, and style aren’t the only factors you need to consider. You shouldn’t forget about fire ratings, especially if you live in an area that’s prone to wildfires. Roofs come in four fire classifications, namely, Class A, Class B, or Class C. You can get the best fire protection from Class A roofs. Meanwhile, unrated roofs provide little to no fire resistance. 

What You Need To Know About Roof Fire Ratings

Here’s a guide to fire roof ratings from a trusted roofing company. 

Class A Roofing

Class A roofs are the best option for every home. To get this rating, a roof must severe fire exposure. It should be able to experience a maximum flame spread of six feet and resist a burning brand measuring 12”x12” and weighing 2,000 grams. Roofs with this rating can last between two to four hours before igniting. Moreover, Class A roofs resist 15 cycles of gas flam turned on and off. 

Roofing materials that have this rating include clay tiles, slate, asphalt glass fiber composition shingles, and concrete tiles. Assembly-rated Class A roofs refer to systems that meet Class A requirements when combined with other components. For instance, shake roofing with a fire-retardant treatment is considered Class B. However, it can achieve the Class A rating when combined with an underlying material like a Type 72 roll roofing material. 

Class B Roofing 

Class B roofing is moderately effective against fire exposure. Roofs with this rating can experience a flame spread of eight feet and withstand a burning brand meaning 6”6” and weighing 500 grams. It usually takes an hour before they ignite and they can resist eight cycles of gas flames turned on and off. The most common roofing materials under this rating are pressure-treated shakes and shingles. 

Class C Rating

Class C roofing only provides limited fire protection. It can experience a maximum flame spread of 13 feet. Roofs under this fire rating can resist a burning brand measuring 1.5”x1.5” and weighing 1/4 gram. They can only last 20 minutes before ignition and resist three cycles of a gas flame turned on and off. 

Turn to State Roofing for high-quality roof repair and replacement services. Give us a call at (360) 794-7164 or fill out our contact form to schedule a free estimate. We serve clients around Seattle, Brothel, and Everett, WA.

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