This heavyweight shingle is composed of a resilient, inorganic glass base that is coated and permeated with additional weather-resistant asphalt. As a three-tab, heavyweight shingle, it provides the assurance of long lasting performance and is surfaced with ceramic colored granules, which protect the asphalt from ultraviolet radiation. Each shingle has release tape and mineral powder applied to the underside, thus preventing any sticking in the bundle. Special algae-inhibiting granules have been added to provide long-lasting algae resistance. This shingle performance characteristics, and can be applied to roofs with slopes of greater than 4:12 (underlayment is strongly recommended on slopes below 6:12). They may also be applied on low slope roofs (2:12 to 4:12) providing the deck is covered with two plies of felt cemented together or one ply of any IKO Ice & Water Protector.