Filling Cracks In Plaster Walls

Expert advice and detailed instructions on repairing the most common plaster wall and ceiling problems including cracks holes and sagging.

Filling cracks in plaster walls.

Treat minor cracks in plaster similar to a drywall crack with joint compound. No matter what the cause. However if the plaster separates from the lath or the structure of the wall it s called blown plaster and it requires a more extensive repair. The plaster keys holding it to the underlying lath can also crack and break over time causing the plaster to partially separate from the wall.

How to repair plaster walls 1. When you hit lath stop the bit won t go through wood pull out the bit and drill another hole about 3 inches from the first and about 2 inches from the crack. Once repaired patch dried apply prime coat over the filled in crack and surface surrounding area. For more about how plaster walls are built see plaster wall construction over time these.

To repair small cracks in plaster you ll need patching compound medium and fine grit sandpaper a sanding block a putty knife a masonry chisel a paintbrush a rag and a screwdriver. Expansion and contraction of the wood studs as they shrink and expand with changing humidity levels can cause the plaster to crack. Some like a small hairline crack usually aren t a big deal. If you are patching a large crack then undercut it remove all the loose plaster and dampen the surface like similar to small crack.

There are a couple of reasons why cracks can form in plaster walls. However if the plaster is pulling away from the lath you first need to shore up the wall with a two step process. For finishing you ll need primer and paint. This will hide the repaired area and gives a fine smooth finishing.

And certain key areas such as above and beside doorways and windows are classic areas of cracking. Repairing small cracks in plaster is easy compared to plastering a whole room. But plaster walls respond to inevitable foundation shifts and climatic changes and can begin to crack. Homes are constantly settling as different construction materials expand and contract at different rates.

Plaster applied to wood lath is held in place by the keys that form when it squishes through the lath. Using a 3 16 inch masonry bit drill a hole in the plaster about 2 inches from the crack. Whether drywall plaster or concrete walls are susceptible to cracks even walls in newly built homes are prone to cracks which normally occur from settling. Mix a batch of plaster and fill the.

Plaster repair is much.