Sheetrock is a brand name for gypsum panels produced by USG Corporation, but it's become commonly used as a generic name for all gypsum panels or drywall. It's manufactured by layering gypsum plaster between sheets of paper to produce a solid panel used to finish interior walls and ceilings. Typically the size and grade of Sheetrock needed will depend on the application, and on local building codes.
Standard Sheetrock is made of regular gypsum, without special treatments or coatings, and is commonly used for interior walls and ceilings in new construction or remodeling projects. Fire-rated, or type X Sheetrock, has additives mixed into the core material. It is manufactured to look like regular Sheetrock, but the additives make it fire-resistant. It's typically used in commercial and multi-family construction where fire-rated material is required. Greenboard, or moisture-resistant Sheetrock, is manufactured with a water-resistant core. It has a chemically treated paper cover and is typically used in areas where moisture is present, such as bathrooms and laundry rooms. Moisture-resistant Sheetrock panels are also available with a fire-resistant core. Blue boards, or veneer plaster base, are treated with a blue paper for use with veneer plaster.
Size and Thickness
The most commonly used size of Sheetrock is 4 feet wide and 8 feet long. These panels are ideal for small and medium sized jobs. Standard Sheetrock in thicknesses of 1/2 and 5/8 inch are used in new residential construction where only a single layer of material is needed. The 5/8-inch Sheetrock is more durable, with greater resistance to fire and impact. The 3/8-inch Sheetrock is used when repairing residential drywall or in remodeling projects, and can be applied in double layers if needed. Sheetrock in 1/2-, 3/8- or 5/8-inch thicknesses are available in 8- through 12-foot lengths.
Quarter-inch Sheetrock is recommended for repairs or remodeling in residential applications and is ideal on curved surfaces because it can be applied in several layers. Typically, these thinner Sheetrock panels are readily available in 4-by-8-foot lengths only because they're fragile and easily damaged in longer lengths.
Core Boards and Liner Boards
Core board is typically 1 inch thick and is used in applications such as partitions. Core boards are available in 24-inch widths with different edge shapes. Linerboards are available in 3/4- and 1-inch thicknesses. These panels may have a coated or printed design or surface that needs no finish treatment. Linerboards are manufactured to be fire-resistant core and are coated with moisture-resistant paper.
Cement Board/Wonder Board
Cement board, also called wonder board, has a core of Portland cement that's reinforced with a glass fiber mesh. It's designed to withstand exposure to moisture without deteriorating and is typically used in bathtubs, kitchens and laundry areas as a base for tile. Standard wonder board panels are 5 feet long and 1/2 inch thick. They are available in 32- or 36-inch widths. The smaller size ensures minimal cutting when installing. You can also custom order 5/8-inch thick panels that are 32 or 48 inches wide and 32 to 96 inches long.