How to Fix a Bubbled Ceiling

Scrape off the bubbles, using a scraping tool. If the ceiling is covered with wallpaper, remove the strips of wallpaper on the affected area to check for bubbles underneath.

Fill in holes and cracks with drywall compound. Smooth the compound with a putty knife, leaving a small mound extending past the surface of the ceiling. Drywall compound tends to shrink as it dries. Allow the compound to dry before proceeding.

Sand the treated areas with sandpaper until the compound is flush with the ceiling's surface. Feather the edges of the compound with sandpaper to make it blend in with the ceiling.

Apply a skim coat over the treated area if there was no existing paint on the wall. Allow this coat to dry before proceeding.

Sand the entire ceiling in preparation for painting or wallpapering. You should paint all areas of the ceiling exposed to water vapor to prevent future bubbling.

Apply a layer of vapor lock primer to the affected area, using a paint roller. Allow the primer to dry overnight, and do not use the shower or stove in the affected room during this period.

Apply two coats of acrylic latex paint over the primer, using a paint roller. Allow the ceiling to dry thoroughly between coats, and do not use the shower or stove in the affected room until the last coat is completely dry.