Repairing Loose Plaster

Before you jump into a plaster repair, learn a little about how the plaster was applied when your house was built. That way, you'll understand how it came loose and what you need to accomplish to fix it.

When the plasterer pushed some of the first coat through the spaces between the lath boards, it oozed behind the strips, creating "keys" that lock the plaster to the strips. Impact or other damage can break the keys, and the plaster can sag from the ceiling or bulge on the wall. Then it's likely to crack.

In a repair job, your first task is to create a new mechanical bond between the surface plaster and the supporting framework. Using special plaster repair washers and screws, attach loose plaster to joists and studs where possible and to lath where necessary.

After you've secured the plaster, the repair proceeds essentially like a drywall finishing project: filling gaps with setting-type compound, embedding tape, and sanding to a smooth surface.

Checklist

Time
The project time depends upon the size of the repair; you also need to allow setting and drying time for the compounds

Tools
Stud finder, drill/driver, drywall mud pan and knife, utility knife

Skills
Using a stud finder, driving screws, applying tape and joint compound

Prep
Remove loose plaster chips, locate studs or joists

Materials
Plaster repair washers with screws, drywall tape, setting-type and premixed compounds, sanding screen