How to Fix a Hole in a Plaster Ceiling From a Water Leak

Cut into the plaster just outside the hole using a utility knife. If the plaster around the hole is water-stained or bubbled, cut around this section and into the undamaged plaster surrounding it. Remove the damaged plaster and create a square shape that is slightly larger than the damaged portion of plaster.

Remove any loose plaster still attached to the wooden lath behind it. If the wood or surrounding plaster is still moist, leave the ceiling to dry before attempting to patch the hole.

Measure the square you’ve cut using a tape measure and use these measurements to draw an identically-sized square on a piece of drywall and then cut the square from the drywall using a drywall knife.

Place the cut drywall into the cut-out section of plaster to ensure it fits. If it is too large, trim the sides in increments until it fits snugly into your ceiling.

Apply wood glue to the back of your drywall square. The back of the drywall is typically brown or gray in color. The front is white.

Place the drywall square into the cut out portion of ceiling and press it into the wood lath and hold it there for about a minute.

Drill about two to three drywall screws into two sides of the drywall to secure it to the lath behind. Smaller patches of less than 1 foot may require only a single screw on each side.

Tape all edges of the patch square using drywall tape and press out any pockets of air.

Apply a thin layer of drywall joint compound or a ready-mix plaster over the patch using a putty knife. Cover the entire patch piece, extending the compound out past the edges of the tape.

Smooth the compound or plaster to blend the edges of the patch into the ceiling and allow the patch to set and dry for about 60 to 90 minutes.

Smooth a second thin layer of compound or plaster and allow this to dry as well. You may require several thin coats of compound to build up the patched area so that it is flush with the remaining ceiling and the edges are no longer visible. Do not try to patch in a single thick coating. This will take longer to dry and may not hold, resulting in cracking and crumbling later.

Sand the patched area lightly to smooth out any bumps and paint to match the rest of the ceiling.