by Myron Ferguson

New mud or tape-on corner beads are more resistant to edge cracking and nail pops than traditional metal corner beads. At the end of a drywall job, I touch up small defects and do a careful cleanup. Then, before I leave the site, I make a final walk-through with the client. This provides a good opportunity to answer any questions and to show off the quality of the job. With the client as witness, I'm also protected from liability for any damage that may occur as other contractors work on the site, such as the door installer who whacks the ceiling, the electrician who slips with the screwdriver, or the mover who damages the outside corner in the foyer. If any such damage occurs and I get called back to make the repair, I'll get paid. Every once in a while, however, I may get a call about an edge crack on a corner bead, or a popped screw or nail along the top edge of a wall — particularly after the first heating season, when the framing has dried and settled. Other common callbacks include loosened or buckled tape in the inside corners, ridging of seams on higher walls — a stairwell wall, for example — or visible ridging on a butted seam. Sometimes, after the painting is done, I'll get a call about seams or fasteners showing through as a different texture (known in the trade as photographing or telegraphing). All of these problems can be prevented or greatly reduced and are easy to correct.

Fastening Drywall

When fastening the drywall, whether with screws or nails, I make certain that the panel is tight against the framing and that the fasteners are properly set (see Figure 1).

I use coarse-thread screws for wood framing and fine-thread for metal. Improper fastener lengths can also cause problems; screws for wood framing should penetrate the framing by 5/8 inch and nails by 7/8 inch. Much shorter or longer is not recommended. Instead of nails, I use screws whenever possible, because they hold much better and are less likely to damage the drywall as they are being installed. The nose of a drywall screw gun also pushes the panel against the framing and limits the screw to exactly the proper depth just below the surface of the drywall, without tearing the paper or damaging the gypsum core. If a screw is set too deep, though, the panel is more likely to pop loose. Other hints. When drywall panels are force-fit into place, they may bow, which can introduce stress and keep the panel from contact with the framing. This creates the possibility of fastener pops. Misaligned and twisted framing can also contribute to fastener failure. Any fastener that misses or is not securely anchored into the framing member may work loose over time and should be immediately removed.

Fastener Spacing
Framing Type	Framing Spacing	Max. Fastener Spacing
Ceiling Joists	16 inches o.c.	12 inches
	24 inches o.c.	12 inches
Wall Studs	16 inches o.c.	16 inches
	24 inches o.c.	12 inches

Floating corner technique. Nail or screw pops and cracking in the seams are common along inside corners at wall-to-wall or wall-to-ceiling intersections. These problems are typically caused by settling stresses or truss uplift. One way to reduce problems is to eliminate fasteners along one or both edges of the corner (Figure 2).Figure 2. Avoid nail and screw pops at wall-to-ceiling intersections by holding back the fasteners on both the wall and ceiling panels. At wall-to-wall intersections, leave the first panel unfastened in the corner and hold it in place with the abutting panel.