To clean mold from the ceiling, wash the affected area with a store-bought mold cleaner, or a mixture of dish soap and water. Let the area dry. Now it’s time to get out the big guns to kill the mold—bleach. Mix one-quarter cup of bleach with one quart of water and apply the solution with a spray bottle or sponge.
There are a couple of ways to prevent the black mold growth on your bathroom ceiling. Check these following steps out: Spray the bathroom ceiling and wall regularly with the combination of water and hydrogen peroxide. If you find them dirty, scrub with the brush and clean up with water.