Cracks occur in plaster walls when there is stress within the material of which the wall is constructed. This stress might be the result of a structural fault or of a minor movement of the earth beneath the building. In the case of a structural fault professional help might be required to correct the problem. In the case of soil movement, which often follows heavy rain or extended periods of drought, the cracks can simply be filled and painted over.
Steps in repairing plaster wall cracks:
- remove all loose plaster
- mix plaster and water to a consistency like toothpaste and push into the cracks to fill their full depth.
- Use a putty knife or other similar tool to scrape off excess filler and even off the surface of the repair.
- Leave enough filler so that it is just a little proud of the wall surface.
- Allow to dry thoroughly, overnight if necessary. Follow directions on filler packaging.
- Sand the repair until the wall is smooth.
- Remove dust.
- Coat with an indoor undercoat and then with two coats of top coat.