Gypsum board is the generic name for a family of panel-type products consisting of a noncombustible core, primarily composed of gypsum, with a paper surfacing on the face, back, and long edges. Often called drywall, wallboard, or plasterboard, gypsum board’s noncombustible core makes it different from plywood, hardboard, and fiberboard. When joints and fastener heads are covered with a joint treatment system, gypsum board provide a monolithic surface that is ready for decorative treatment.
Gypsum board walls and ceilings have a number of outstanding advantages:
- Fire Resistive
- Sound Attenuating
Gypsum board is an excellent fire resistive material. It is the most commonly used interior finish where fire resistance classifications are required. Its noncombustible core contains chemically combined water which, under high heat, is slowly released as steam, effectively retarding heat transfer. Even after complete calcination, when all the water has been released, it continues to act as a heat insulating barrier. In addition, tests conducted in accordance with ASTM E 84 show that gypsum board has a low flame spread index and smoke density index. When installed in combination with other materials it serves to effectively protect building elements from fire for prescribed time periods.