How to Plaster Old Walls

The easiest way to repair cracked, wavy plaster walls is with more plaster. A process called skimcoating flattens and smoothes those wavy old walls by filling in the contours and indentations with a paper-thin layer of new plaster. See your local home improvement store for plaster that can be used for skimcoating.

10-inch wide drywall knife
Plaster
Paper drywall tape
Drywall sander
Paint and paint rollers and brushes

Instructions

- 1
  Use your wide drywall knife to remove all loose paint and plaster from the wall, scraping it thoroughly. Dig out around any deep cracks or holes with the corner of the knife to remove all the loose plaster.
- 2
  Spread plaster over the holes and cracks. Rip off pieces of drywall tape to fit into any of the holes, setting the tape in the plaster. Spread more plaster over it, using the drywall knife to get it smooth and flat.
- 3
  Let it set for 12 hours.
- 4
  Spread a thin layer of plaster over the entire whole wall with the drywall knife, starting at one end and working across. Drag the long edge of the knife over the surface at a shallow angle, so the plaster left on the wall is generally paper-thin, but thicker where it fills in holes, cracks and depressions.
- 5
  Let the plaster dry for four hours. Scrape the knife over it to remove off any ridges.
- 6
  Spread a second coat of plaster over the wall in the same manner as the first coat, keeping it thin and flat. Let it dry. Scrape it flat.
- 7
  Apply a third coat. Let it dry for 12 hours. Lightly sand it, making sure it's flat. Re-paint the wall.

Animals That Nest in Walls

How to Remove Plaster From Drywall

Wall Repairs