In this video, This Old House general contractor Tom Silva explains how to patch plaster.
1 Measure area of plaster wall that's loose or damaged and needs to be replaced.
2 Cut a drywall patch slightly larger than the damaged wall section.
3 Hold drywall patch against plaster wall, and mark its outline with utility knife.
4 Using a utility knife, score the plaster along the patch outline.
5 Pry off the loose plaster with a painter's tool; clean up the debris.
6 Set the drywall patch against the wall and secure it with 1 ¼-inch drywall screws.
7 Cover the seams around the patch with adhesive-backed nylon joint tape.
8 Apply a thin coat of joint compound to the taped seams and to screw heads.
9 Allow compound to dry, then sand lightly with 150-grit sandpaper.
10 Apply a second, slightly wider coat of joint compound to the seams.
11 Allow second coat of compound to dry; sand with 150-grit sandpaper.
12 Apply a third, even wider coat of joint compound to the seams.
13 Smooth dried compound with 320-grit sandpaper.
14 Finish the wall with a coat of primer and two paint topcoats.
3 to 6 hours, depending on size of repair
Repairing plaster is always dusty, dirty work, but it's not particularly difficult
used to measure damaged wall area
used to drive drywall screws
used to apply joint compound
used to hold joint compound
used to patch plaster
used to make straight drywall cuts
3. 1 ¼-inch drywall screws
used to secure drywall patch
4. Adhesive-backed nylon joint tape
used to bridge seams between drywall and plaster
5. Joint compound
used to fill seams around drywall patch
6. 150-grit and 320-grit sandpaper
used to sand dried joint compound
7. Primer and paint
used to protect floor
9. Wet/dry vacuum
used to collect dust and debris
10. Plastic trash bags
used to collect plaster pieces