Repairing a Large Hole in Drywall
Repairing large holes in drywall—anything over 6 or 8 inches—is different from repairing a small hole in drywall. Small holes can be patched over with drywall tape or a self-adhesive drywall patch, but large holes need a more rigid material to span over the larger opening. The simplest solution is also the best: cutting a patch from drywall and securing it with wood backing strips and screws. Once the patch is in place, you tape and "mud" (apply joint compound) over the seams, just like when installing new drywall. The result is a permanent repair that is just as strong as the surrounding surface and, if you finish the patch carefully, will not be visible.
Supplies You Will Need
- Framing square
- Drywall saw
- Scrap lumber or plywood strips, at least 3 inches wide
- Tape measure
- Wood saw
- Piece of drywall (thickness must match drywall in repair area)
- 1 1/4-inch coarse-thread drywall screws
- Drill with screwdriver bit
- Self-adhesive mesh drywall joint tape
- Utility knife
- Drywall joint compound
- 6-inch drywall knife
- 150-grit sanding sponge
- Drywall spray texture (optional)
- Primer and paint
Prepare the Opening
Trim the edges of the hole to create straight sides and a square or rectangular overall shape. Use a framing square and a pencil to mark cutting lines on the drywall, then cut along the lines with a drywall saw.
Warning: Make sure there is no wiring or plumbing behind the drywall surface before cutting.
Install the Backing Strips
Cut two pieces of lumber or plywood to a few inches longer than the long sides of the hole. Place one piece into the hole, along one of the long sides, so the strip is centered over the drywall edge (half is behind the drywall and half is exposed. Secure the strip with drywall screws driven through the drywall and into the strip. Keep the screws about 1 inch from the drywall edge, and space them about 6 inches apart.
Repeat the same process to install the other backing strip at the other long side of the hole. If the hole is more than 10 inches wide, cut two short strips to fit between the long strips. Install the short strips along the two shorts sides of the hole.
Install the Drywall Patch
Cut a piece of drywall to fit the hole. It doesn't have to be a snug fit, but the seams should be not more than about 1/8 inch wide. Position the patch over the hole and secure it to the backing strips with screws. Keep the screws about 1 inch from the edges of the patch and space them 6 inches apart. Note: The patch must be the same thickness as the existing drywall; typically, this is 1/2 inch.
Tape the Seams
Cover each seam with self-adhesive mesh drywall joint tape, overlapping the tape strips at the corners, and cutting the strips to length with a utility knife. Make sure the tape lies flat, with no wrinkles or bulges.
Mud the Seams
Cover the drywall tape with a thin layer of drywall joint compound, using a 6-inch drywall knife. You should be able to see the mesh through the compound. Let the compound dry, then scrape the surface with the knife to remove any burrs or clumps. Apply another thin layer of compound, extending it beyond the edges of the first layer. Use the knife to "feather" the edges of the wet compound over the surrounding drywall so it gradually tapers to nothing. Let the second layer dry, then scrape again and add a third layer. Let the third layer dry.
Sand the Mud
Sand the dried compound with a sanding sponge to smooth the surface. Be careful not to over-sand so that the mesh tape shows through. If desired, you can wet-sand with a wet-sanding sponge to keep down dust. Clean off all sanding dust with a dry rag.
If desired, add a surface texture, such as an "orange peel" spray texture, to match the surrounding surface.
Prime and Paint the Patch
Cover the entire patch area with a coat of primer, using a paintbrush. Let the primer dry. Apply two or more coats of paint to match the surrounding area, as needed. Alternatively, if the wall or ceiling could use a new paint job, this is a great time to paint the whole thing, which will help hide the patch.