Fasteners for Drywall

This story explains the uses and benefits of various drywall fasteners.

Nails driven into wood split apart wood fibers, and the friction between the nail's shank and the wood gives the fastener its holding power. Although you can purchase smooth-shank drywall nails, those with annular rings (commonly called ringshank) have up to 20 percent more holding power for virtually the same price. Although that may sound like a modest increase in strength, it can make the difference between a smooth wall and one that develops unsightly nail pops.

The vast majority of professional drywallers now choose screws because they have up to 31/2 times the pullout resistance of nails. That translates into far fewer popped fasteners.

Longer is not necessarily better
The prime culprit causing nail pops is framing lumber that has too high a moisture content. As the lumber shrinks (principally in width) during drying, it pulls away from the drywall while the nails try to stay in the same position. When the lumber's movement is stronger than the nail's grip, the nail pops.

Somewhat surprisingly, attempting to prevent the problem by using longer nails for the installation simply makes the situation worse. The deeper you go into lumber, the higher its moisture content, and the more the nail moves when the wood dries. As a result, long nails pop more than short ones.

The best prevention is to use a fastener that produces adequate holding power with minimal lumber penetration. Refer to the chart (opposite right) to choose ringshank nails. Or even better: Select screws when driving into new lumber.

Nail pops are less of a problem in a remodeling project when you're hanging drywall on well-seasoned framing lumber.

Essential fasteners
Annular ring drywall nails offer good pullout resistance in wood. Smooth-shank nails aren't recommended; they work out easily.

Type W bugle head screws have a coarse thread pattern that gives excellent holding power in wood framing.

Type S bugle head screws have a tip that drills its own hole in metal studs and other steel framing members. The fine thread pattern is designed for maximum gripping power in metal. Some type S screws have a high/low thread design like the trim head screw for slightly faster driving.

Type G laminating screws have a large diameter and coarse threads for holding power when driven into gypsum board. This allows you to build multilayer applications without driving fasteners into the framing. The base layer must be at least 1/2-inch thick when using these screws.

Trim head screws attach door jambs, baseboards, and other moldings to drywalled surfaces over metal studs.

The modified truss head screw is the special fastener for joining metal studs to tracks.

Backerboard screws are made from stainless steel or from steel with a special corrosion-resistant coating. The stainless-steel screw shown here has nibs under the head that cut a countersink in cementious backerboard so that the head is flush.

Drive systems
The most-used drive system for drywall screws is the cruciform (cross-shaped) #2 phillips. It's an efficient and time-proven design, but it won't work properly if your drive bit is worn, rounded, or chipped. Replace the bit at the first sign of wear. The phillips ACR bit has ribs that resist the tendency of the bit to lift out of the slot (cam out) under driving stress. When you use an ACR bit, you reduce the need to supply as much downward pressure to keep the bit engaged.

Square drive (sometimes called Robertson) screws are even more resistant to camout. The drive and recess have such tight tolerances that you can achieve a "stick fit" -- where the fastener won't fall off the bit regardless of position. However they are more difficult to load onto the bit than phillips heads. Trim head screws typically have a #1 square recess; #2 square is more common on construction screws.


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