Economical to produce, relatively easy to install and widely available, asphalt shingles are today’s most popular roofing material—not only because they’re less costly than wood, wood shakes, tile, metal or slate, but also because their guaranteed life span pits them favorably against competitors. At least a dozen major U.S. and Canadian building-product manufacturers market asphalt shingles, including GAF, Owens Corning, and CertainTeed.
Asphalt’s primary purpose in roofing shingles is to serve as a waterproofing agent. Asphalt also holds the granules in place and adds to the overall strength of the roofing shingle. The best asphalt will stay flexible and will not dry out or become hard or brittle for the expected life of the roofing shingle.