What is Gypsum Drywall?
A description of gypsum drywall must first begin with a discussion of gypsum itself. Gypsum, a naturally occuring mineral, is composed of calcium sulfate (CaSO4) and water (H2O). Also referred to as hydrous calcium sulfate (CaSO4.2H2O), gypsum is mined from deposits formed by ancient seabeds as a raw material for many different manufacturing, industrial, and agricultural uses. Over 80% of the gypsum mined is used in manufactured products such as drywall. Gypsum possesses many attributes that make it an attractive construction material. Calcined gypsum can be wetted to form a paste that can be directly applied to a structure’s surface or that can be molded into a desired shape; the gypsum hardens upon drying. Gypsum is naturally fire resistant. Gypsum drywall, often referred to as gypsum wallboard or sheet rock, replaced gypsum plaster as the major material used for interior wall surfaces because of its ease of installation. Gypsum drywall consists of approximately 90% gypsum and 10% pa
