Roof shingles are a roof covering consisting of individual overlapping elements. They are typically flat, rectangular shapes laid in courses from the bottom edge of the roof up, with each successive course overlapping the joints below. Roof shingles are made of various materials such as wood, slate, flagstone, metal, plastic, and composite materials such as fiber cement and asphalt shingles. Ceramic roof tiles, which still dominate in Europe and some parts of Asia, are still usually called tiles.

Asphalt shingles are the most common roofing material in the United States. They are made of a continuous web or sheet of fiberglass mat, which is reinforced with glass fibers of specific length and diameter bound together with stable resins and binders. The fiberglass is wound into large rolls at the fiberglass mill, which are then “unwound” at the start of the roofing shingle manufacturing process. Asphalt is the main water-resistant ingredient in shingles, and it is an end-product of oil refining. The asphalt used in shingles is processed to a higher degree of toughness needed for asphalt shingle performance. The roofing asphalt has to be “oxidized” by blowing air through the hot asphalt, increasing its viscosity. Crushed stone granules are applied to the shingle surface to improve looks and durability.

Composite or synthetic shingles are a relatively new type of shingle material that are made from a blend of materials, including asphalt, fiberglass, and other polymers. They are designed to mimic the look of natural materials such as wood, slate, or clay and aim to increase the durability, strength, and resistance to weather elements relative to these natural materials. Rubber shingle roofs are typically made from 95% recycled material from a variety of sources including recycled tires. Metal roofs may consist of aluminum, zinc, copper, or steel.

In summary, roof shingles can be made of various materials such as wood, slate, flagstone, metal, plastic, and composite materials such as fiber cement and asphalt shingles. Asphalt shingles are the most common roofing material in the United States and are made of a continuous web or sheet of fiberglass mat, which is reinforced with glass fibers of specific length and diameter bound together with stable resins and binders.