What are Asphalt Shingles Made of?
Asphalt roof shingles are the most common covering used on residential properties in North America. Early shingles were made by saturating rag-felts with asphalt and by coating each side of the saturated felt with an asphalt-mineral filler-coat, covering the top surface of the shingle with mineral granules (sunlight and weather resistance) and coating the bottom surface with a material to prevent shingles from sticking together in storage or shipment. Beginning in the 1940’s the felt mat was changed to a zero rag-content using wood fibers and cellulose (newspaper). More recently many manufacturers began producing shingles using a fiberglass mat to replace the felt. The fiberglass mat was thought to have good tear resistance, possibly slightly better fire resistance, and as the mat was generally thinner than the felt mat, we believe that there were also economic advantages for both the manufacturer (less asphalt used in the mat) and the roofing installer (lighter material, easier to ins
