Filling Cracks In Plaster Walls

For more about how plaster walls are built see plaster wall construction over time these.

Filling cracks in plaster walls.

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. Expert advice and detailed instructions on repairing the most common plaster wall and ceiling problems including cracks holes and sagging. Everyday life with its bumps and bangs also takes its toll on plaster walls. Homes are constantly settling as different construction materials expand and contract at different rates.

And certain key areas such as above and beside doorways and windows are classic areas of cracking. Once repaired patch dried apply prime coat over the filled in crack and surface surrounding area. Some like a small hairline crack usually aren t a big deal. Expansion and contraction of the wood studs as they shrink and expand with changing humidity levels can cause the plaster to crack.

If you are patching a large crack then undercut it remove all the loose plaster and dampen the surface like similar to small crack. Repairing small cracks in plaster is easy compared to plastering a whole room. Cracks can appear for a number of reasons. Plaster applied to wood lath is held in place by the keys that form when it squishes through the lath.

Mix a batch of plaster and fill the. There are a couple of reasons why cracks can form in plaster walls. How to repair plaster walls 1. 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.

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. This will hide the repaired area and gives a fine smooth finishing. 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. However if the plaster is pulling away from the lath you first need to shore up the wall with a two step process.

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. No matter what the cause. For finishing you ll need primer and paint.

Treat minor cracks in plaster similar to a drywall crack with joint compound.