Roofing is a type of construction work that involves the installation of materials to cover the roof of a building. SLATE is a type of material used in roofing, consisting of thin layers of rock that are layered together and held in place with nails or glue. COVERING is another term for roofing, referring to the process of COVERING the roof of a building with materials such as SLATE, TILE, or THATCH. THATCHING is a type of roofing material made from plant material such as straw, reeds, or grass. THATCH is another term for this type of material. TILE is a type of roofing material made from fired clay or other materials, and is often used to create a waterproof layer on the roof of a building.