The challenge of fixing holes in drywall is in covering the gap. To fix a large hole in drywall, make a clean cutout around the hole and insert a replacement piece of wallboard into the hole. (Drywall is also known as wallboard, gypsum board, and Sheetrock.)
Cut a patch from a piece of scrap drywall that’s larger than the hole.
Save yourself time and trouble — make the cut out a square or rectangle, even though the hole may be a different shape.
Trace the patch size over the hole area on the wall.
Place the patch over the hole area and trace around it with a pencil.
Cut out the drywall along the traced lines.
Use a straightedge to guide your knife as you cut the drywall.
If the patch is large, you can make the project go much faster by using a drywall saw to cut the wall. Just be careful to avoid wiring and pipes that may be hidden behind the walls.
Use a sharp utility knife to trim away any loose or protruding paper facing or loose pieces of gypsum.
Drywall is made of a sheet of gypsum, covered on both sides with a layer of paper (a paper facing). Use a sharp utility knife to trim away any loose or protruding paper facing or loose pieces of gypsum.
Position the precut anchor board.
Holding a precut anchor board in the middle, insert it into the hole in the wall. Each end should extend equally underneath the surrounding wall.
You could also use wallboard clips instead of an anchor board.
Secure the anchor board to the wall.
Using wallboard screws and a screw gun, screw through the existing wall and into one end of the anchor board. Maintain pressure on the center of the board to keep it tight against the surrounding walls. Still holding onto the center of the board, fasten the other end of the anchor board to the wall.
Add a "handle" to the patch and place the patch into the hole, butting it up against the anchor board.
To make the handle, insert a screw about halfway into the center of the drywall patch with screwdriver. Leave enough of the screw exposed to form the handle.
Secure the patch into the hole and remove the center screw handle.
Holding the center screw if necessary to keep the patch in place, use the screw gun to insert a screw all the way through the drywall patch and into the anchor board. Repeat this step three more times until the drywall patch is firmly attached to the anchor board.
Apply wallboard tape to the edges of the patch.
Smoothly apply the tape around all for edges of the patch.
Apply wallboard compound over the tape.
Apply a thin coating of the compound to all four sides of the patch. Let the compound dry completely.
Apply a second thin coat.
This application is intended to smooth and conceal the tape. Don’t apply the compound thickly or the repair will be as obvious as the hole was.
Sand the patch until smooth, and wipe up dust with a tack cloth.
Use a fine-grit paper to smooth out the surface.
Paint over the patch with primer.
Don’t skip this step or you’ll end up with a permanently goofy-looking, non-matching area.
Apply touch up paint to the patch in your wall color.
This is why you saved that half a gallon of leftover wall paint.