An asphalt shingle is a type of roof shingle. They are one of the most widely used roofing covers because they are relatively inexpensive and fairly simple to install.
Two types of asphalt shingles are used: organic and fiberglass or glass fiber. Organic shingles are generally paper (waste paper) saturated with asphalt to make it waterproof, then a top coating of adhesive asphalt is applied and ceramic granules are then embedded. In the case of algae-resistant shingles, a portion of the granules contain leachable copper ceramic coated, designed to protect against discoloration from algae on the roof. This does not protect from moss growth but does slow the growth. Moss feeds on algae and any other debris on the roof. Most manufactures offer a 5 to 10 year warranty against algae growth.