There are two basic types of asphalt shingles. Each consists of a core material that is coated with asphalt, and then covered with granules. This core of base material may be either fiberglass mat or organic felt.
Fiberglass shingles are so called because they are built on a fiberglass mat reinforcement. Asphalt coating is applied directly to this mat and protective colored granules are embedded into the coating. Fiberglass shingles has superior dimensional rigidity, are lighter and offers better heat and humidity resistance than organic shingles.
Owens Corning Fiberglas shingles carry a Class A fire resistant rating from Underwriters Laboratories (UL), the highest fire rating available.