When most people think of drywall, they probably picture the standard 4x8 panel that's been in use since drywall first became popular. But this is by no means the only size or type of drywall available today. Panels come in lengths up to 16 ft., in 48-in. and 54-in. widths and in a wide variety of special-use panels, including moisture-resistant, fire-resistant and abuse-resistant panels, 1/4-in. flexible panels, 1/2-in. high-strength ceiling panels, and foil-backed panels. In this section, We'll guide you through the various types, their uses, the thicknesses and lengths available and the framing specifications for each type. With this information, you'll be able to make the right decision about what type of drywall to order when it comes time to plan the job.

Regular drywall 

Regular drywall panels are 48 in. wide and come in a variety of lengths from 8 ft. to 16 ft. (see the image). Panels are available in four thicknesses (5/8 in., 1/2 in., 3/8 in. and 1/4 in.), each with specific applications (and framing requirements).

Five-eighth-inch regular drywall

Five-eighth-inch drywall is the thickest regular drywall available and provides the best single-layer application on walls and ceilings over wood and metal framing. The panels provide greater resistance to fire and deaden sound better than the other thicknesses; and because the panels are stiffer, they are more resistant to sagging. Five-eighth-inch drywall can be used on walls and ceilings with framing members (wall studs and ceiling joists) spaced up to 24 in. on center (o.c). If you install (or "hang") the panels parallel to ceiling joists, the joists should be no farther apart than 16 in. o.c. to prevent sagging. If you hang 5/8-in. panels perpendicular to ceiling joists, a water-based texture can be applied only if the ceiling joists are 16 in. o.c. or closer (again, to avoid sagging).

Half-inch regular drywall

Half-inch drywall is the most commonly used drywall in both new construction and remodeling. It is usually used as a single layer over wood or metal framing, but it can be installed in two layers (with staggered seams) to increase fire resistance and sound control. The framing requirements for 1/2-in. drywall are the same as for 5/8-in. panels. If the framing is farther apart than the recommended spacing, wood or metal furring strips can be attached across the framing to the specified on-center spacing.

Three-eighth-inch regular drywall

Three-eighth-inch drywall was initially used to replace wood lath as a backing for plaster. When drywall first became popular, 3/8 in. was widely used on walls and ceilings in new construction, but it was eventually replaced by the more durable 1/2-in. drywall. Today, 3/8-in. drywall is used mainly in repair and remodeling work to cover existing surfaces or as a backing for paneling. It is also used in double-layer applications. The maximum distance between framing members on walls and ceilings is 16 in. o.c. For installation on studs and joists that are more than 16 in. o.c. apart, use a double layer of 3/8-in. drywall with adhesive applied between the two layers.

Quarter-inch regular drywall

Quarter-inch drywall is a lightweight panel that is used to cover old wails and ceiling surfaces in remodeling jobs or for sound control in double-layer or multilayer applications. When hanging 1/4-in. drywall over old plaster or drywall, adhesive is used between the old surface and the new drywall in combination with screws to help strengthen the panels and reduce sag. The thin panels are too weak to install in a single layer over bare studs or joists without backing. Regular 1/4-in. drywall is easily bent and can be used to form curved surfaces with long radii (5 ft. or more) if applied dry, or shorter radii (3 ft. or more) if applied wet. A better choice for curved surfaces, however, is Win. flexible drywall, which is discussed later in this chapter. Maximum on-center framing for 1/4-in. regular drywall is 16 in. (either as a double layer or as a single layer over an existing solid surface).