Asphalt shingles continue to be among the most popular types of roofing because of their durability, longevity, easy installation and low price. Another way asphalt shingles have been perfected over the years is with granules, which shield the shingles from ultraviolet (UV) rays and increase their resistance to fire. If the shingle has no granules, it will be left exposed to sunlight, which will cause it to deteriorate prematurely. But what causes granule loss?