Looking for advice on how to repair this large and deep damage to an outside corner on an old wall. Materials are plaster over rock lath, for what it's worth. You can see the rock lath through the plaster in the first photo. Haven't found anything online about how to repair a corner with damage this deep.

In the second picture you can see the big picture of what I'm repairing. Just as a sanity check, I'm repairing the other smaller corner cracks with mesh tape. There are also some small hairline cracks that I'm skimming over. If any of that sounds wrong, please let me know.

Corner Damage Big Picture

1 Answer 1


I think I'd be installing modern corner bead. I expected to see an early version of it in your corner, but there's apparently nothing.

Grab a stick of corner bead and some long drywall nails. Pre-drill the plaster if you have to, then nail it on, making sure to get good penetration in the framing.

I'd use a setting-type joint compound for the rough fill to add toughness, then skim with your favorite joint compound.

  • I agree with corner bead otherwise next time it gets bumped it has to be repaired all over again.+
    – Ed Beal
    Commented Dec 10, 2018 at 19:46
  • That makes a lot of sense. Think the whole corner should be done or just the area around the damage?
    – TypeKG
    Commented Dec 11, 2018 at 0:23
  • To keep everything on plane I would run a full-height bead. I think you'd have a hard time blending it in otherwise.
    – isherwood
    Commented Dec 11, 2018 at 2:21

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