Repairing Damaged Corner Bead: Dents, Cracks, and Separation

Published December 29, 2024 by Mike Sullivan

Key Takeaways

  • Minor dents can be filled with joint compound without removing the bead
  • Corner bead that's pulled away from the wall needs to be re-secured with screws
  • Severely damaged sections should be cut out and replaced with new bead
  • Use setting compound for corner repairs since it's harder and more dent-resistant
  • Metal corner bead dents easier than paper-faced or vinyl alternatives

Moving a couch down the hallway is how I learned about corner bead repair. The couch won. The corner lost. What had been a crisp 90-degree edge was now a crumpled mess of dented metal showing through cracked mud.

I stood there looking at it, genuinely unsure what was under the surface. I'd patched holes before, fixed nail pops, even taped a few seams. But corners had always been this mysterious structural thing I assumed required professional intervention.

Turns out corner bead is just a strip of metal or plastic that reinforces drywall corners. When it gets damaged, you either repair it in place or cut out the bad section and install new bead. Both are totally doable. The couch damage took me about two hours to fix, including drying time between coats.

What Corner Bead Actually Is

Corner bead is a long strip of material, usually metal, that covers the outside corners where two pieces of drywall meet. It serves two purposes: it creates a straight, crisp corner line, and it protects the vulnerable drywall edges from impact damage.

The bead itself is covered with joint compound during finishing, so you don't see it when the wall is done. What you see is a smooth corner that's actually just mud over a metal or plastic core.

Most homes built before the 2000s have metal corner bead. Newer construction often uses paper-faced or vinyl bead, which is more flexible and less prone to denting. My 1978 house has original metal bead everywhere, and after 45 years of use, plenty of it shows wear.

Fixing Minor Dents

Small dents where the corner still has its basic shape are the easiest to fix. You don't need to touch the bead itself.

Scrape away any loose or flaking compound around the dent. Use a 6-inch knife. Get back to solid material but don't go crazy trying to strip the whole corner.

Fill the dent with joint compound. I prefer setting compound for corners because it dries harder and resists future impact better than regular mud. Push the compound into the dent firmly, then smooth it to match the surrounding surface.

Let it dry completely. Setting compound cures in 45 to 90 minutes depending on the type. Apply a second coat if needed, feathering the edges. Sand smooth when fully cured.

The repair won't be as strong as an undamaged corner, but it will look fine and hold up to normal use. I've got several repaired dents that have lasted years without issue.

Reattaching Loose Corner Bead

Sometimes corner bead pulls away from the wall without actually denting. You'll see a gap between the bead and the drywall, often with cracked mud running along the edge. This happens when the original nails or staples lose their grip, or when the house settles and puts stress on the corners.

First, scrape away the loose compound along the separated edge. You need access to the bead itself.

Push the bead back against the drywall and secure it with drywall screws. I use 1-1/4 inch screws, one every 8 to 10 inches along the loose section. The screws should go through the bead flange into the framing behind the drywall. If you can't hit framing, at least get solid drywall purchase.

Cover the screw heads and re-mud the corner. Apply thin coats, letting each dry before adding the next. Three coats is typical. Sand smooth and prime before painting.

Replacing Severely Damaged Sections

When the bead is crushed, bent, or otherwise mangled beyond simple filling, you need to cut out the damaged section and install new bead. This sounds intimidating but it's really not bad.

Removing the Old Bead

Score the mud about 2 inches away from the corner on both sides using a utility knife. Pry off the loose compound to expose the bead flanges. Use a hacksaw or metal snips to cut the bead above and below the damaged area. Pry the damaged section off the wall. It's usually held on with nails or staples that pull out fairly easily once the mud is cleared.

Installing New Bead

Cut a new piece of corner bead to fit the gap. Home Depot sells 8-foot lengths for about $4. Test fit it in place, trimming as needed for a snug fit against the existing bead at top and bottom.

Secure the new bead with drywall screws every 8 inches. Make sure it's aligned with the existing corner line above and below. Even a slight jog will be visible after painting.

Apply compound over the new bead, feathering into the existing finish on both sides. This takes three coats minimum to blend properly. Sand, prime, paint.

The Paper-Faced Alternative

After repairing my third corner in the same hallway, I started using paper-faced corner bead for replacements. It's a metal or plastic core with paper flanges instead of metal ones. The paper embeds into the mud instead of just being covered by it, which creates a stronger bond and smoother finish.

It's also more flexible. The couch incident that crushed my metal bead probably would have only dented paper-faced bead, if that. Carlos, my painter friend, switched to paper-faced years ago and swears by it.

The installation is slightly different since you embed the paper flanges in wet mud rather than screwing through metal. But the results are worth the learning curve.