DIY Drywall Repair for Large Holes in Walls

This method can be used to repair drywall and plaster holes of about a square foot down to a few inches. The setting and drying times in these instructions assume the use of 30 minute setting-type joint compound like Durabond45®. When using a slower acting compound or ready-mixed drywall compound increase these times by double or more. For help applying joint compound use the techniques on the Skim Coating page.

Using a straight edge, mark the wall surrounding the damaged area to form a square. This will make it easier to cut a new piece of drywall to fill the hole. Cut along the marks with a drywall saw or knife. For plaster with wood lath, use a reciprocating saw to cut cleanly thru the wood strips. Bore a pilot hole large enough for the blade and insert the saw. Keep the saw base pressed firmly against the wall while the saw is running to avoid blade vibration that would crack the surrounding plaster.

If there's any contamination around the hole, seal the wall surface with a shellac–based primer–sealer and let it dry for about an hour before proceeding with the repair. Bubbling may develop in the finished repair if contamination prevents bonding between the wall and joint compound.

Measure the squared hole and cut a piece of drywall to be about 2 inches wider on all sides than the opening. Turn the drywall patch over and with a pencil, mark the location of each side of the hole on the back. Mark the patch to be just a little smaller than the opening so it will fit easily into place.

With a sharp drywall knife, score each mark, tracing the lines as accurately as possible.

Snap the drywall along one side at a time and pull the gypsum away leaving the facing paper attached to the patch.

With all four sides removed the patch should look like the one here. Test the patch for size by placing it in the opening. Be sure it fits easily, trim the gypsum if necessary for a smooth fit.

Mix a cup of setting joint compound as described in Skim Coating Techniques. Thin the mud with a little extra water. This will make it easier to apply the new patch to the wall. Apply a thick coat of the mixed mud around the perimeter of the hole to be patched. Let mud coat the inside edges of the hole also.

Press the drywall patch into the opening. Lightly press the paper flaps into the mud so they make good contact. Push lightly on the center of the patch to be sure it is seated into the hole and level with the wall or slightly indented. Don't allow the patch to sit above the wall level. This will create a bulge in the finished repair.

Use a drywall joint knife to squeeze the mud from between the wall and the paper edges of the patch. Work around the perimeter of the patch. Press the joint knife hard against the wall to squeeze all but a very thin coat of mud from between the paper and the wall stroking away from the center of the patch. Return the excess mud to the rim of the pan with each stroke.

Avoid repeated skimming in one place, the drywall paper will be softened by the wet mud and may tear. If this happens straighten out the tear and skim it lightly. If the new patch is not level with the wall, gently push it to level or slightly indented before the mud sets. A slight depression will allow for building the wall surface up with the subsequent coats of mud. Allow the mud to set for about 30 minutes or more. Be sure the mud has set before continuing.

Mix more mud and apply it over the entire patch and onto the surrounding wall. Immediately skim off the excess and return it to the pan. Try to leave a level coat of mud over the patch. The patch will still have a rough finish and will need a couple more coats of mud to smooth it out. Allow the mud to set for 30 minutes and sand with 120 medium grit sandpaper to remove any protrusions such as ridges or bubbles in the mud surface. Mix and apply another batch of mud and skim the excess using perpendicular strokes to the previous coat.

Allow the final coat of mud to set and dry for at least an hour. Sand the repair lightly, feathering the edges into the surrounding surface. Brush any dust from the repair before priming and painting. If you are using flat latex finish paint, you can use it to prime the repair. If you are using semi–gloss or other shiny paint, prime with flat latex paint or a latex primer first.