Avoid Tapered Edges on Outside Corners
If you hang a sheet of drywall with the tapered edge along an outside corner, it will be hard to install the corner bead accurately (left). The corner of the bead will lie too low, making it difficult to cover with joint compound. The solution is to place cut edges along an outside corner (right).
Check the Fit Before Fastening
Even with careful measuring, you’ll often run into an outlet hole that doesn’t quite fit. The common mistake is to screw the drywall to the framing before trimming the opening. Then the drywall will break around the electrical box (left), requiring extra time to patch. The key to solve this problem is to check the fit before you press the drywall tight to the wall.
After carefully measuring and cutting out the openings in your sheet of drywall, hold the drywall in place. If the fit is close, fasten the sheet with a few screws along the top edge or well away from the outlet openings. Trim excess drywall away along tight box edges with a utility knife (top right) until the drywall slides easily over the outlet boxes (bottom right). Then finish fastening the drywall.
Leave a 1/8-in. Gap
There’s no reason to measure and cut drywall for an exact fit. It’ll usually just cause trouble. Jamming in a piece that’s too tight will crumble the edge or break out a corner (left). And removing a piece to shave a too-tight edge is messy and time consuming. A loose fit avoids this problem. Cut it to leave about a 1/8-in. gap at edges (right). In fact, when you’re hanging the ceiling, keep in mind that 1/2 in. along the perimeter will be covered by drywall on the walls. And the same is true of inside wall corners. So you can safely cut these pieces 1/4 in. less than the actual measurement and leave a gap in the corner if necessary. Even a piece whose edges aren’t covered should be cut a little short. It’s easier to fill a 1/8-in. gap with setting-type compound than to cut and repair a broken edge or corner.