How to Repair Water Damage to Plaster

The sort of trowel that would be used to spread joint compound.

Water damage to plaster in the home can be a real eye sore. Additionally, once the plaster is wet there is the increased potential for mold problems. Repairs to plaster that has been water damaged can be accomplished with the right materials and a little patience. The cost of all the materials needed depends on the size of the repair but generally the job can be completed for under $50, according to 2010 prices.

Things You'll Need

• Utility knife
• Pencil
• Claw hammer
• Joint compound
• Drywall sandpaper
• Trowel
• Box fan
• Carpenter's square
• Clothe or sponge

Instructions

1. Draw a square around the damaged area using a carpenter's square and a pencil. Be sure to include a couple of inches on all sides of the damage to make sure that all the damaged plaster is repaired.

2. Cut out and remove all the plaster in the square with a utility knife. It may require many passes with the utility knife to remove all the plaster but removing all the old plaster will insure a better job upon completion.

3. Remove or pound flat any nails that may be sticking up in the lathe that is under the plaster. The idea is to get the surface as smooth as possible.

4. Place a box fan by the open area and run for as long as it takes until the surface feels completely dry. If any moisture gets trapped in the wall it could cause mold problems in the future.

5. Smooth joint compound into the area with a trowel. The object is to spread the joint compound into the affected area as smooth as possible. Steady and even strokes with the trowel works best. Make sure to work the joint compound into the area so that there are no low or high areas and no air pockets. Let the joint compound dry for 24 hours.

6. Sand the area lightly with drywall sandpaper to smooth out any ridges or high spots that may have developed in the drying process. Wipe with a damp clothe or sponge before painting to remove any drywall dust from the sanding.