- Before treating the stain, locate its source, which may be a water leak.
- To get rid of any potential mold, stir up a 50/50 mix of bleach and water.
- Wear rubber gloves and use a sponge to wash the stain or carefully spray the mixture in a spray bottle. It’s possible the bleach/water mix could remove the stain, but unlikely. The goal here is to kill the mold.
- Once the bleach mix has dried, use an oil or shellac-based primer to cover the stain. It can be a spray can primer or a traditional brush or roll-on primer. Spray or brush on one coat.
- Once the primer has dried, use an acrylic or water-based paint and paint brush to cover the stain. It’s likely the entire ceiling or wall will need a fresh coat to make it match.