Combine 1 part bleach with 5 parts water and gently dab the mixture onto the stains using a soft cloth.
Mildew stains on popcorn ceiling.
If its just a darkening of the ceiling and its really only a sand texture you can clean the surface using a bleach and water solution to remove any loose mold growth let dry then paint using a good quality mold resistant primer.
Lightly mist the area to prevent additional water damage.
Zinzer makes several types.
Mix water with bleach in a spray bottle and apply to the ceiling.
If the ceiling holds up to the liquid test you can remove the yellow stains and mildew using a bleach solution.
Repeat the process as needed to completely.
To prevent mold regrowth coat your ceiling with a stain killing primer then paint over it with a mildew resistant.
Other than aesthetic purposes mildew removal is necessary to prevent the spores from spreading and further contaminating the bathroom.
Also depending upon how much mold or mildew it is that you have.
Humid air and poor ventilation contribute to mildew growth on bathroom ceilings.
If your ceiling is moldy you may have a water leak in it or behind the walls.
Lightly mist the area to prevent.
Mildew is a fungus that contains a musty odor and appears as multicolored spots on ceilings.
Here are some tips on how to clean popcorn ceilings remove cobwebs stains and discolorations and return them to their mid 20th century glory.
Many homeowners got rid of their popcorn ceilings in the half century since they were all the rage.