How to: Repair Damaged Walls & Ceilings
If you’ve been a homeowner for long enough, then you have probably at some point witnessed a wall in your property bubble up and start to crumble.
When plaster is applied to the wood or metal wire lath foundation, it is held in place by certain “keys” which form when the plaster is pushed through the lath. Over time, however, these “keys” can start to break-down, which in turn results in crumbling, cracking plaster falling off the lath.
Alternatively, water damage and plumbing issues can cause discoloration and peeling. Installing poor quality plaster is just asking for trouble, as plaster can be damaged by simple acts like installing wall hangings, moving furniture around which scratches the walls; it really doesn’t take much.
Fortunately, it’s quite simple to repair these minor flaws in your wall and ceiling plaster, and with some guidance you can easily do it yourself! Here’s how:
If the plaster is firmly stuck to the lath behind it, then you can fix it. If, however, when you push the wall, the plaster flexes likes it’s been detached from its foundation, you’re going to need a professional’s help.
- - Widen the crack slightly with a can opener and scrub the area with a solution of water and TSP.
- - Cover the groove with small pieces of fiberglass-mesh joint tape.
- - With a small putty knife, apply a setting-type joint compound to the crack. Smooth it over, and let it dry.
- - Apply another coat of compound and then sand it lightly, so it blends into the wall smoothly.
- - Paint over.
Large cracks are a little bit trickier, but are fixed in a similar way to small cracks.
- - Widen the crack and dampen the edges with a sponge.
- - Half fill with patching plaster, and then, once it has dried, score the plaster with a nail. This will allow the next batch of plaster to latch on and stay in place.
- - Apply more patching plaster and let it dry.
- - Apply a coat of finishing plaster, sand, and paint.
While cracks and holes can, most often, be easily fixed, sagging plaster is an indicator of deeper issues. This shows that the keys keeping the plaster and lath firmly together are starting to weaken, or that the lath is pulling away from its foundation.
The first sign of this is usually sagging, which could eventually lead to the entire plaster surface collapsing.
While some say you can do this yourself, we do recommend hiring a professional for such repairs, as a sagging ceiling can be difficult and dangerous to repair on your own.