How to Patch Drywall | Martin Painting Co.
Large Holes
Step 1: Check for wires
Photo 1: Draw a rectangle around the break with a straightedge or square. Look or put your hand through the break to feel for wires or other obstructions. Then cut out the section with a drywall saw or utility knife.
Before cutting out the damaged area, check the wall for obstructions. Often you'll find a wire, pipe or duct (Photo 1). If so, work carefully around them with a drywall or keyhole saw. Or make a shallow cut by repeatedly scoring the line with a sharp utility knife. It's easier to add backer board than to try to cut the drywall over studs (Photo 2). Cut the backer boards about 4 in. longer than the height of the hole. Pine or other soft wood works well. Hold them tight to the backside of the drywall when fastening them. Hold the boards carefully so the screw points won't prick your fingers if they pop out the backside. The drywall screws will draw the boards in tight. Sink the screw-heads slightly below the drywall surface.
Step 2: Insert backer boards
Photo 2: Insert 1x4 backer boards at each end of the hole and drive a pair of 1-1/4-in. drywall screws through the drywall into the boards to anchor them. Fit and screw a drywall patch to the boards.
Measure the thickness of the drywall (most likely 1/2 in.), and look for a large enough scrap from a damaged piece at a home center, rather than buy a full 4 x 8 ft. sheet. Cut it to size and screw it into place, spacing the screws every 6 in. Taping the edges of the patch to make it invisible is the trickiest part of the job (Photos 3 and 4). Buy a gallon tub of drywall compound and a roll of paper tape. You can use mesh tape, but it isn't as strong. If you have a lot of repairs, also buy a sack of 20-minute setting compound. It hardens quickly and doesn't shrink, so it's ideal for filling cracks and gaps before applying the joint tape. For smoothest results, also pick up flexible 6- and 10-in. taping knives.
Step 3:
Photo 3: Lay a 1/8-in.-thick bed of drywall compound over the joints and press paper tape into the compound with a flexible 6-in. knife. Immediately apply a thin layer of compound on top of the tape. Allow to dry.
Apply a coat of compound and tape to each joint (Photo 3). Thin the compound a bit with water to help embed the tape. Smooth the tape with the 6-in. knife, pulling out from the center toward each end. Squeeze some, but not all, of the compound out from under the tape so you don't create a big hump on the wall. Immediately apply a light coating to the topside of the tape, tapering it out onto the wall. The second and third coats are to blend and smooth the taped joints so they'll be invisible when painted. After each coat is dry, set a straightedge against the wall to check for obvious dips and bumps. Knock off bumps and ridges with your taping knife. Add more coats as needed. Then sand, prime and paint.
Tip:
When possible, leave a few inches of drywall at corners so you won't have to spread taping compound onto adjacent walls or ceilings and repaint them as well!
Martin Painting Company Akron/Canton Ohio
