Roof shingles are individual overlapping elements used to cover roofs. Typically, they are flat, rectangular shapes laid in courses from the bottom edge of the roof up, with each successive course overlapping the joints below. Shingles are held in place by the roof rafters and can be made of various materials, such as wood, slate, flagstone, metal, plastic, and composite materials like fiber cement and asphalt shingles. Ceramic roof tiles, which still dominate in Europe and some parts of Asia, are usually called tiles.
Roof shingles may deteriorate faster and repel water less effectively than wall shingles. Nonetheless, they are a very common roofing material in the United States.