How to Fill Large Holes in Sheetrock and Drywall

Measure the length and the height of the hole with a tape measure. Ensure that you measure the part of the hole that is not broken through as well as the hole itself. Add 6 inches to each measurement. This is the size necessary for the drywall patch.

Draw out a patch, using the measurements from the hole, onto a piece of drywall. Use a straight edge to draw four straight lines, creating a square patch. Cut the patch out of the replacement piece of drywall with a drywall saw or a utility knife.

Place the patch over the hole in the wall. Trace the outline of the patch onto the wall with a pencil. Look or feel inside the wall for any plumbing pipes or electrical wires. If there are any obstructions, you must use care when cutting through the drywall to ensure you do not cut through the obstruction.

Cut the drywall around the hole where you made the tracing using a drywall saw or utility knife. If there are obstructions behind the wall, use the utility knife to cut the wall. When using a utility knife to cut the wall, make three slices inside the tracing as well as slicing through the trace lines. This makes it less difficult to remove the damaged wall.

Remove the piece of wall around the hole. Measure the height of the cut-out hole and add 6 inches. Cut two pieces of 1-by-3-inch board to the height measurement with a circular saw or hand saw.

Insert one board into the hole until it is behind the wall. Hold the board against the back of the wall at one end of the hole. The board should be clearly visible. Screw a drywall screw through the wall and into one end of the board with a cordless screwdriver or drill with a Phillips-head adapter bit. Repeat for the opposite end of the board. Attach the second board on the opposite end of the hole. The boards act as a backing for your patch.

Position the patch into the hole. Screw the patch into the two backer boards. Spread a thin film of drywall compound onto the patch seam with a putty knife. Apply drywall tape to the compound, and smooth the tape with the utility knife.

Apply drywall compound over the tape with the putty knife. Allow the compound to dry thoroughly, usually at least 24 hours. Sand the compound with 100-grit sandpaper once it dries. Wipe off the sanding dust from the wall with a damp cloth. Paint the patched area to match the wall.