How to Fix an Oversize Electrical Box Cutout

Updated: Aug. 18, 2023

Fast fix for a common goof

FH11JAU_FIXBOX_01-2Family Handyman
An oversize drywall cutout around an electrical box can ruin the appearance of an otherwise perfect taping job. The best way to fix it is with drywall compound and joint tape.

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Permanent repair

Photo 1: Fill with setting-type compound

Bevel the edge of the drywall with a utility knife. Then fill in the gap with fast-setting joint compound.

Photo 2: Mud and tape

Spread the fast-setting compound into the gap and surrounding area and embed the tape right up to the edge of the electrical box. Let it set up and apply the final two coats of lightweight compound. Sand with a medium-grit sanding sponge.

We’ve all done it—cut the electrical box opening too large. Sure, you can cover it with jumbo electrical covers, but that can look pretty stupid, especially if there are other boxes nearby. Instead of squishing joint compound into the gap (it’ll always crack), try this fix.

First prepare the gap and fill it with compound (Photo 1). Then apply joint tape and additional mud coats (Photo 2).

Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • Dust mask
  • Taping knife
  • Utility knife

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here’s a list.

  • Lightweight joint compound
  • Medium grit sanding sponge
  • Paper joint tape
  • Setting-type joint compound