How to Repair Plaster in an Old House

Cracks

• 1

  Protect the floor and area under the walls that you are repairing by laying down a tarp. Use a dust mask and eye protection when working on old surfaces and keep the air well ventilated.

• 2

  Drill holes into the plaster abound 2 inches from the crack line on either side. Make sure the masonry bit goes through the plaster and just touches the wood lathe in the wall. Drill holes from the top of the crack all the way down to the bottom every 3 inches.

• 3

  Vacuum out the holes with a vacuum cleaner using the hose attachment to remove all the dust and plaster particles.

• 4

  Spray each hole with the adhesive prep and allow it to dry for about 10 minutes or according to the directions on the container.

• 5

  Squeeze a small amount of plaster adhesive into each of the holes until the space is filled. Wipe up any extra that overfills the holes with a clean and damp sponge or rag.

• 6

  Screw plastic plaster washers directly into the center of the crack aligned with the holes drilled, but only use one washer for every 6 inches. Tighten the screw gently into place, bringing the plaster back into contact with the wooden lathe. Dry the adhesive overnight.

• 7

  Remove the plastic washers and apply a thin layer of joint compound to the entire area. Wait for the compound to dry, sand smooth and reapply the compound to any unsmooth areas. Dry, sand and apply again if necessary. Paint as desired.

Bulging Plaster

• 8

  Secure any bulging plaster by using thin plaster washers to push the plaster toward the lathe in the wall. Use as many as necessary for a snug fit, tightening them so that they are just below the surface of the wall.

• 9

  Apply a thin layer of joint compound to the area covering the washers. Dry overnight and sand smooth. Reapply layers of compound until the wall is smooth.

• 10

  Wipe down the area with a damp sponge or rag to remove the excess dust.

Plaster Holes

• 11

  Clean out the area inside the hole using a vacuum cleaner with a hose attachment.

• 12

  Cut a section of wire mesh with a pair of tin snips so that it fits into the hole, flush against the lathe. Screw it in place with a few drywall screws.

• 13

  Spray the area with a mist of water to dampen the lathe, preventing the old surface from pulling the moisture from the new plaster too quickly.

• 14

  Apply a layer of perlite gypsum plaster so that the wire mesh is covered and the hole is mostly filled. Allow the plaster to dry completely.

• 15

  Smooth a layer of joint compound over the hole so that it's flush with the surface. Dry overnight and sand it smooth. Wipe down the surface with a damp rag to ready the surface for paint.