Problems With Plaster Walls

Superficial Cracks

• Moderate settling of the house can cause small hairline cracks, but more commonly these occur as the plaster ages and slightly weakens. Because the cracks are small, there is no reason to remove and repair the plaster. Instead, the crack can be filled in with a small amount of drywall patching compound and sanded to a smooth finish.

Deep Cracks

• If the plaster has deep, wide cracks more than 1/4 inch wide, it could be a sign of structural issues with the home, especially if the cracks are near the corners of the house, doors or windows. If you have deep cracks, remove any loose or broken pieces of plaster inside the crack and patch the crack with mesh tape and drywall compound. Deeper cracks can be a sign that the plaster ears between the lath have begun to break off and can no longer hold the plaster in place on the wall.

Bulging or Sagging Plaster

• If the plaster is bulging or sagging away from the wall, it indicates a major problem with the plaster. When this problem occurs, the plaster ears have broken off from the lath. If this is a new problem, you might be able to correct it by trying to screw the plaster back into the lath, then patching over the screw holes. If the bulge is severe, tearing out the plaster and either re-plastering or hanging new drywall on may be your only option.

Difficulty Removing Plaster

• Removing plaster walls can be a problem because of the weight of the material, plus the underlying lath means you have to remove two layers of material. Removal first requires you to scrape the heavy plaster off the wall with a shovel and dispose of it. Once that is done, you have to go back and pry all of the wood lath off the walls. From start to finish, it's a messy and strenuous job.