Lightly mist the area to prevent additional water damage.
Mildew stains on popcorn ceiling.
Water mildew and smoke stains.
Mildew is a fungus that contains a musty odor and appears as multicolored spots on ceilings.
Lightly mist the area to prevent.
Mix water with bleach in a spray bottle and apply to the 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.
Also depending upon how much mold or mildew it is that you have.
To prevent mold regrowth coat your ceiling with a stain killing primer then paint over it with a mildew resistant.
A leaky roof may cause yellow water marks or mildew to form on a your popcorn ceiling.
If your ceiling is moldy you may have a water leak in it or behind the walls.
Here are some tips on how to clean popcorn ceilings remove cobwebs stains and discolorations and return them to their mid 20th century glory.
Humid air and poor ventilation contribute to mildew growth on bathroom ceilings.
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.
Zinzer makes several types.
Combine 1 part bleach with 5 parts water and gently dab the mixture onto the stains using a soft cloth.