To fix a water-damaged ceiling, repair the source of water leakage in the roof, dry the ceiling, fill any holes in the ceiling with joint compound or plaster, and sand, prime and paint the ceiling. Paint the entire ceiling with uniform paint for the best results.
- Fix the leaking roof, and dry the ceiling
Repair the broken roof, or replace the leaking pipe to stop farther water leakage. Cover the floor and furniture with a tarp, and use towels to blot both sides of the ceiling to remove excess water. Repeat the blotting as needed, and change saturated towels until the ceiling stops dripping. For a bulging ceiling, put a bucket below the ceiling, poke the ceiling with a knife, let all the water collect in the bucket, and allow the ceiling to dry. Drying the ceiling prevents mold.
- Fill the holes, and sand the ceiling
If necessary, scrape the ceiling with a paint scraper to remove chipping paint and smooth the ceiling surface. Fill the holes with joint compound or plaster, and sand the surface again.
- Apply primer, and paint the ceiling
Apply a primer coat to the ceiling, let the primer dry, and apply another coat. Leave the second coat to dry, and paint the entire ceiling with uniform color.