Mold on the Bathroom Ceiling: Clean It, Fix the Moisture, Keep It Away

A bathroom ceiling is the warmest, most humid surface in the room after a hot shower. Moisture condenses there, and if it does not dry before the next shower, mold has everything it needs. The spots you see are a symptom; the problem is moisture. The EPA states it directly: the key to mold control is moisture control.

Is it surface mold or something bigger?

What you see	Likely situation
Small scattered black or gray spots, mostly above the shower	Surface mold from condensation
Spots return within weeks of cleaning	Ventilation not removing moisture
Brown ring or stain with mold in it	Possible leak from above, roof or plumbing
Ceiling feels soft, sags or crumbles	Water damage in the drywall: needs repair
Mold over a large area, or musty smell throughout	Larger moisture problem, possibly hidden
Mold on a textured “popcorn” ceiling	Do not scrape; see below

Size up the job

The EPA says that if the moldy area is less than about 10 square feet, roughly a 3-foot by 3-foot patch, in most cases you can handle the job yourself. If there has been a lot of water damage, mold covers more than 10 square feet, or the water was contaminated, such as from sewage, the EPA recommends following its professional remediation guidance or hiring an experienced contractor.

Protect yourself

The EPA recommends gloves, goggles and an N-95 respirator when cleaning mold, to avoid breathing mold and spores. Open a window and run the exhaust fan. Keep children and anyone with asthma or allergies out of the room while you work.

Clean small areas

1. Mix mild detergent in warm water.
2. Scrub the mold off the ceiling with a sponge or soft brush. The EPA recommends scrubbing mold off hard surfaces with detergent and water and drying completely.
3. Wipe with clean water and dry the area thoroughly with rags and a fan.
4. Bag and discard the rags.

Absorbent materials that are moldy, such as ceiling tiles, may need to be removed and replaced, the EPA notes, because mold can be hard to clean out of porous materials.

Fix the moisture

• Run the exhaust fan during every shower and afterward until the mirror and walls are clear of fog, or install a timer or humidity-sensing switch so it runs long enough automatically.
• Check the fan works. Hold a piece of tissue near the grille; it should be pulled firmly against it. Clean the grille and fan of dust.
• Make sure it vents outdoors. A fan that exhausts into the attic puts moisture where it causes more damage. If you are not sure, check in the attic.
• Keep the door or a window open after showering.
• Look for leaks above the ceiling if a stain accompanies the mold.

Repaint only after it is clean and dry

The EPA warns not to paint or caulk moldy surfaces: clean up the mold and dry surfaces before painting, because paint applied over moldy surfaces is likely to peel. Once the ceiling is clean and dry, prime with a stain-blocking primer and use a paint labeled for bathrooms or high humidity, in a satin or semi-gloss finish that sheds moisture.

Textured ceilings

Older popcorn and textured ceilings can contain asbestos; the EPA lists textured paint and patching compounds used on walls and ceilings among products that may contain it. Do not scrape or sand a textured ceiling to remove mold. Have it tested by an accredited professional first, and consider professional cleanup.

Common mistakes

• Painting over mold.
• Cleaning without fixing ventilation, so mold returns.
• Using a fan vented into the attic.
• Scrubbing a textured ceiling of unknown composition.

When to call a pro

Call a mold remediation professional for areas larger than about 10 square feet, for mold that returns quickly despite good ventilation, or when there is a strong musty smell suggesting hidden mold. Call a contractor or electrician to install or reroute an exhaust fan, a roofer or plumber if there is a leak above, and an accredited asbestos professional before disturbing textured ceilings.