Method 4-Patches For Truly Large Holes
Go through the third method until you have the rectangle cut out of the wall. At this point, you’re going to need a good screw gun and drywall screws.
Get some plywood and cut it out with a rim about one inch wider than the hole, two inches if you’re worried about your ability to be precise. You’ll need to insert it into the hole in your wall and screw it off, preferably at the corners. If this sounds like it’s going to be difficult, wait for the trick I’m about to give you.
Before insertion, drive a screw on the face of the board towards one side, but inside the outer edges of the rectangle. Let the screw hang out about half an inch past the face of the drywall and balance the board with the top-left or top-right corner up.
Drive the first screw, but not too tight. You’ll be using it as a rotation point holding it to the wall.
Now, you can lift the board up by the screw in the face and do the opposite corner. It’s best to go across diagonally so you have the maximum amount of support from the first two screws. Finish zipping it up with the other two screws and the hard part is done.
Now you’ll need to put in the drywall patch itself. This part is easy enough, and if you’d like you can definitely screw it off to the backing before the next step. Just place the screws near the edge.
Place fiberglass joint tape over the seams, which should be pretty tight anyways, and mud it up. Let the mud dry, sand it smooth, and you have the best repair you can make without actually removing the whole sheet and replacing it.
For what it’s worth, you might find the repair to be troublesome. You have two choices here, either hide it manually with a piece of furniture or hope that your finishing skills are up to par and try to mud, texture, and re-finish the patch-job.
The latter is a pretty simple procedure, but deserves its own guide.