What is Gypsum Board?
Gypsum board is the generic name for a family of panel-type products consisting of a noncombustible core, primarily of gypsum, with a paper surfacing on the face, back, and long edges. Gypsum board is often called drywall, wallboard, or plasterboard and differs from products such as plywood, hardboard, and fiberboard, because of its noncombustible core. It is designed to provide a monolithic surface when joints and fastener heads are covered with a joint treatment system. Gypsum is a mineral found in sedimentary rock formations in a crystalline form known as calcium sulfate dehydrate. One hundred pounds of gypsum rock contains approximately 21 pounds (or 10 quarts) of chemically combined water. Gypsum rock is mined or quarried and then crushed. The crushed rock is then ground into a fine powder and heated to about 350 degreesF, driving off three fourths of the chemically combined water in a process called calcining. The calcined gypsum (or hemihydrate) is then used as the base for gyps
Gypsum Board is also called Drywall, Gyp Board, Rock Lath or Sheetrock. With paper on both sides and a gypsum plaster center, the gypsum board product gained popularity because of ease of installation, compared to plastering. Skilled drywall mechanics achieve reasonably plumb, square and true walls quickly. The traditional gypsum board panel size was 4′ x 8′. But many more options are now readily available. Lengths of 10′ and 12′ are now common, as are 4′ – 6″ width, which are used for 9′ – 0″ ceiling heights. Type X gypsum board varies from regular gypsum board because Type X has noncombustible fibers added to the gypsum to improve fire resistance. The tapered edges along the length of the gypsum board allows drywall finishing compound to be placed without creating much of a raised surface between the adjacent boards. Due to these tapered edges, a more true (or straight) wall can be built. Since the ends of gypsum board are not tapered but are square, it’s desirable to eliminate end b
