Black spots on a bathroom ceiling: mold, mildew or a leak?

Do this first: check the ceiling before you clean

Before you scrub, check whether this is surface growth or a ceiling getting wet from above. That decides whether it is a weekend chore or a call to a pro.

1. Look at the pattern. Note whether the spots are scattered specks over the shower or tub, or one blotch with a defined edge.
2. Touch the area lightly with a gloved hand. A sound ceiling feels firm and dry. NC State Extension lists discoloration, sagging, bowing and wet spots on ceilings as moisture signs to check for. ^[1]
3. Measure the patch. EPA's line for doing the job yourself is about 10 square feet, roughly a 3 foot by 3 foot patch. ^[2]
4. Think about what sits above the ceiling: another bathroom, a toilet or tub, the attic or the roof. CDC says mold grows where there is moisture, such as around leaks in roofs, windows or pipes. ^[3]
5. Test the exhaust fan. With the fan running, hold a single sheet of toilet paper in front of it. If the paper stays in place, the fan is working. ^[1]
6. Take a dated photo of the spots so you can tell later whether they are spreading.

What are the black spots on a bathroom ceiling?

Often, the spots are mold feeding on moisture from your shower. EPA notes that showering adds to indoor humidity, and that when warm, humid air contacts a cold surface, condensation may form. ^[4] A ceiling under an attic or roof can be that cooler surface. EPA says adding insulation to cold surfaces such as roofs helps reduce condensation. ^[5]

Mold or mildew? FEMA describes mildew and molds as fungi, simple microscopic organisms that thrive anywhere there is a moist environment. ^[6] University of Florida Extension puts it plainly: mildew is a type of mold. ^[7] In everyday speech, many people say mildew for thin gray or black growth in a bathroom. UGA Extension notes that mildew typically appears on surfaces such as bathroom tile. ^[8]

The label does not change what you do. CDC says it is not necessary to know what type of mold you have, and all molds should be treated the same with respect to health risk and removal. ^[9] If you can see it, EPA says that in most cases sampling is unnecessary, and CDC does not recommend mold testing. ^{[10] [3]}

What about black mold? Black color is not a diagnosis. CDC says mold can look like spots of many different colors and can smell musty. Exposure to damp and moldy environments may cause a variety of health effects, or none at all. People with asthma or mold allergies may have severe reactions, and people with weakened immune systems or chronic lung disease may get lung infections from mold. ^[3] If you have health concerns, EPA says to talk with a health professional before you start cleanup. ^[10]

Surface growth or a leak from above: how to tell

Shower mold tends to stay thin and on the surface. A leak tends to leave a wet, growing blotch and damaged drywall.

Spots that keep returning on drywall can mean the growth is in the material, not just on it. EPA says absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy, because mold can grow on or fill in the empty spaces and crevices of porous materials and may be difficult or impossible to remove completely. ^[10]

Water from above can also hide mold. EPA lists roof materials above ceiling tiles, from roof leaks or insufficient insulation, and areas inside walls around leaking or condensing pipes as places mold hides. It warns that investigating hidden mold requires caution when it means disturbing places where mold may be growing; removing wallpaper, for example, can release a massive amount of spores. If you believe you have a hidden mold problem, EPA says to consider hiring an experienced professional. ^[10]

Wet drywall has a short window. EPA says wallboard may be dried in place only if there is no obvious swelling and the seams are intact; if not, it should be removed, discarded and replaced. ^[11] Massachusetts guidance says to cut out wallboard that has not dried enough within 48 hours. ^[12]

How to clean small surface spots safely

If the patch is under about 10 square feet, EPA says that in most cases you can handle the job yourself. Its method is simple: scrub mold off hard surfaces with detergent and water, and dry completely. ^{[2] [5]} On a ceiling, do this only if the drywall is firm and dry and nothing above is leaking.

1. Turn on the exhaust fan, and open a window or the door for fresh air. ^[3]
2. Put on an N-95 respirator, long gloves that reach the middle of the forearm, and goggles without ventilation holes. ^[10] Goggles matter more overhead, where loosened bits fall toward your face.
3. Set up a steady step ladder, and cover the tub, floor and anything below with an old sheet or plastic.
4. Mix detergent and warm water in a bucket.
5. Scrub the spots with a sponge or soft brush. Wring it out often so you do not soak the drywall.
6. Wipe the area with a clean, damp cloth, then dry it completely. Leave the fan running. ^[5]
7. Bag the used sponges and rags for the trash, and wash the clothes you wore.
8. Wait to prime or paint until the ceiling is clean and fully dry. ^[10]

What about bleach? EPA says using a biocide such as chlorine bleach is not recommended as a routine practice during mold cleanup. ^[10] If you choose to use it, CDC says to use no more than 1 cup of household laundry bleach in 1 gallon of water and to open windows and doors for fresh air. Never mix bleach with ammonia or other cleaners. ^[3] EPA gives the same warning: never mix chlorine bleach solution with other cleaning solutions or detergents that contain ammonia, because toxic fumes could be produced. ^[10] If you washed the ceiling with detergent first, rinse with plain water before any bleach goes on.

How to stop the spots from coming back

The way to control indoor mold growth is to control moisture. ^[5] For mold in the shower or elsewhere in the bathroom that seems to reappear, EPA says more ventilation, running a fan or opening a window, and cleaning more often will usually prevent it from recurring, or at least keep it to a minimum. ^[2]

• Run the fan every shower. EPA says to run the bathroom fan or open the window when showering. ^[10] NC State Extension says everyone in the household should turn the fan on when showering or bathing, and open a window if there is no fan. ^[1]
• Keep it running after. The Department of Energy's Building America Solution Center recommends leaving the fan running for one hour after a shower for humidity control, and using a timer switch so it shuts off on its own. ^[13]
• Make sure it vents outside. The fan should vent outdoors, not into the attic, a crawlspace or the space between floors. ^[13]
• Watch the humidity. EPA says to keep indoor relative humidity below 60 percent, ideally between 30 and 50 percent. ^[10] CDC's advice is no higher than 50 percent. ^[3] A hygrometer from a hardware store shows the number.
• Dry condensation quickly. If you see condensation or moisture collecting on windows, walls or pipes, EPA says to act quickly to dry the surface and reduce the moisture source. ^[10]
• Address a cold ceiling. EPA says adding insulation to cold surfaces such as roofs helps cut condensation. ^[5]
• Paint only after cleaning. Clean and dry the ceiling before painting, and consider a paint with a mold inhibitor added, as CDC suggests. ^{[10] [3]}
• Clean on a schedule. CDC suggests cleaning bathrooms with mold-killing products and keeping carpet out of bathrooms. ^[3]

When a mold remediation company makes sense

Call a mold remediation or water damage restoration company that serves your area when any of these apply:

• The moldy area is larger than about 10 square feet. For that size, EPA points readers to its remediation guide for schools and commercial buildings, which it says applies to other buildings too. ^[2]
• The spots come back soon after a careful cleaning, even with the fan running and humidity under control.
• Water is coming from above: an upstairs bathroom, plumbing, the attic or the roof. EPA suggests an experienced professional when you suspect hidden mold. ^[10]
• The drywall is soft, swollen or sagging. EPA says wallboard with obvious swelling or failed seams should be removed and replaced. ^[11]
• There has been a lot of water damage, or the water was sewage or otherwise contaminated. EPA says that calls for a professional with experience cleaning buildings damaged by contaminated water. ^[10]
• Someone in the home has asthma, mold allergies, a weakened immune system or chronic lung disease. ^[3] Ask a doctor whether they should stay out of the cleanup.

If you hire a contractor, EPA says to make sure they have experience cleaning up mold and to check references. ^[2] For budgeting, HomeAdvisor's June 2026 cost guide puts mold remediation at an average of $2,368, with a typical range of $1,223 to $3,757. ^[14]

Insurance depends on the cause. Washington's insurance commissioner says homeowner insurance usually covers sudden leaks but may not cover gradual leaks, and usually does not cover mold unless it comes from water damage the policy covers. Some insurers provide limited mold coverage. ^[15] Check your own policy and talk with your insurer.

Renting? Report the spots and any leak to your landlord in writing. EPA tells renters to report all plumbing leaks and moisture problems right away to the building owner or manager. ^[10]

Common questions