Plaster is made of lime or gypsum, sand, and water and is one of the oldest building materials still in use—plaster applied to the Egyptian pyramids four thousand years ago is still hard and holds its integrity. Today it is applied in three layers: a base coat, a thick coat of plaster for strength, and a finishing coat.
Plaster can be applied to many surfaces, including wood lath, metal mesh, wallboard, or masonry. Some homes may even have ornamental plasterwork formed by hand or cast in molds and applied to walls and ceilings. Plaster can be applied so that there are patterns such as swirls and peaks.
Plaster can be painted or pigment can be mixed into plaster before it is applied. Wallpaper and tile can also be easily applied over plaster.
