Backer-Strip Patch a Fist-Size Hole
Category: Drywall ·
Difficulty: Intermediate ·
Time: 1.8h ·
Estimated cost: $32
Tools needed
- Drywall jab/keyhole saw
- Drywall T-square (4 ft)
- Utility knife
- Drill/driver with drywall dimpler bit
- 6" taping knife
- 12" taping knife
- Mud pan
- Sanding sponge (220 grit)
Materials needed
- 1/2" drywall scrap (for the plug) (1 pc)
- 1x3 furring / plywood backer strips (2 ea)
- 1-1/4" coarse-thread drywall screws (1 lb) (1 lb)
- Paper joint tape (250 ft) (1 roll)
- Setting-type 'hot' compound (bag) (1 bag)
- All-purpose joint compound (quart) (1 qt)
- Drywall primer/PVA (quart) (1 qt)
Execution steps
Square the hole
Cut the ragged hole into a clean rectangle with a jab saw and T-square — straight edges are far easier to patch.
Duration: 10 min
Install backer strips
Slide a furring/plywood strip behind the wall, longer than the opening. Hold it tight to the back of the drywall and screw through the existing wall into the strip on each side, dimpling the heads just below the surface without tearing the paper.
Duration: 15 min
Cut and fasten the plug
Cut a drywall plug to fit the opening with a ~1/8" gap. Screw it to the backer strips, again dimpling each head.
Duration: 15 min
Tape the seams
Bed paper tape over all four seams in a thin coat of mud, pulling it tight with the 6" knife to squeeze out excess.
Duration: 15 min
Three coats of mud
Fill and feather in three progressively wider coats — the first in setting-type mud — letting each dry before the next.
Duration: 30 min
Sand, prime, paint
Sand flush, prime the bare mud, and paint two thin coats feathered into the wall.
Duration: 25 min
Safety first
- Kill the breaker for nearby outlets, switches, and light cans before cutting into the wall.
- Don't break the paper face when dimpling screws — a torn-paper screw pops later.
- Wear a dust mask and eye protection.
When to hire a pro
Holes with a broken stud, plumbing, or live wiring in the cavity — or anything bigger than ~10" — call a pro or move to a stud-to-stud replacement.
Back to all DIY Guides ·
AyX Estimator — Take the guess out of construction.