Fasteners

Figure 5-3.—Drywall fasteners. sanding, ensure you’re wearing the required personnel protective gear to prevent dust inhalation. A foot lift helps you raise and lower drywall sheets while you plumb the edges. Be careful when using the foot lift—applying too much pressure to the lift can easily damage the drywall. Fasteners Which fasteners you use depends in part upon the material underneath. The framing is usually wood or metal studs, although gypsum is occasionally used as a base. Adhesives are normally used in tandem with screws or nails. This allows the installer to use fewer screws or nails, leaving fewer holes that require filling. For reasons noted shortly, you’ll find the drywall screw the most versatile fastener for attaching drywall to framing members. NAILS.— Drywall nails (fig. 5-3, view A) are specially designed, with oversized heads, for greater holding power. Casing or common nailheads are too small. Further, untreated nails can rust and stain a finish. The drywall nail most frequently used is the annular ring nail. This nail fastens securely into wood studs and joists. When purchasing such nails, consider the thickness of the layer or layers of drywall, and allow additional length for the nail to penetrate the underlying wood 3/4 inch. Example: 1/2-inch drywall plus 3/4-inch penetration requires a 1 1/4-inch nail. A longer nail does not fasten more securely than one properly sized, and the longer nail is subject to the expansion and contraction of a greater depth of wood. Smooth-shank, diamond-head nails are commonly used to attach two layers of drywall; for example, when fireproofing a wall. Again, the mil length should be selected carefully. Smooth-shank nails should penetrate the base wood 1 inch. Predecorated drywall nails, which may be left exposed, have smaller heads and are color-matched to the drywall. SCREWS.— Drywall screws (fig. 5-3, view B) are the preferred method of fastening among professional builders, cabinetmakers, and renovators. These screws are made of high-quality steel and are superior to conventional wood screws. Use a power screw gun or an electric drill to drive in the screws. Because this method requires no impact, there is little danger of jarring loose earlier connections. There are two types of drywall screws commonly used: type S and type W. Type S.— Type S screws (fig. 5-3, view B) are designed for attachment to metal studs. The screws are self-tapping and very sharp, since metal studs can flex away. At least 3/8 inch of the threaded part of the screw should pass through a metal stud. Although other lengths are available, 1-inch type S screws are commonly used for single-ply drywall. Type W.— Type W screws (fig. 5-3, view B) hold drywall to wood. They should penetrate studs or joists at least 5/8 inch. If you are applying two layers of drywall, the screws holding the second sheet need to penetrate the wood beneath only 1/2 inch. TAPE.— Joint tape varies little. The major difference between tapes is whether they are perforated or not. Perforated types are somewhat easier to bed and cover. New self-sticking fiber-mesh types (resembling window screen) are becoming popular. Having the mesh design and being self-sticking eliminates the need for the first layer of bedding joint compound. JOINT COMPOUND.— Joint compound comes ready-mixed or in powder form. The powder form must be mixed with water to a putty consistency. Ready-mixed compound is easier to work with, though its shelf life is shorter than the powdered form. Joint compounds vary according to the additive they contain. Always read and follow the manufacturer’s specifications. ADHESIVES.— Adhesives are used to bond single-ply drywall directly to the framing members, furring strips, masonry surfaces, insulation board, or other drywall. They must be used with nails or screws. 5-4