Your place · Cleaning and laundry
Mold and moisture: what to watch for
Mold grows wherever things stay wet. Dry leaks and spills within 24 to 48 hours, keep humidity below 60 percent, and fix the water problem, or the mold comes back. You can usually clean a patch under about 10 square feet yourself with detergent, water, gloves and goggles. Anything bigger, anything after sewage or a flood, and every leak in a rental goes to your landlord, in writing.
What to know
- Look and sniff. Mold can be spots of many colors, and it can smell musty. If you see or smell it, remove it. Source: CDC
- Renting? Report every plumbing leak and moisture problem to your landlord or building manager right away. Source: EPA Take photos first, and put the report in writing so there's a record.
- Size it up. If the moldy area is under about 10 square feet, roughly a 3-by-3-foot patch, you can usually clean it yourself. Bigger than that, a lot of water damage, or water from sewage calls for a professional. Source: EPA
- Suit up: long gloves to mid-forearm, goggles without vent holes and, to limit what you breathe in, an N-95 respirator that fits properly. Source: EPA
- Scrub hard surfaces with detergent and water, then dry them completely. Source: EPA
- Throw out what you can't clean. Porous things like ceiling tiles and carpet may have to go, because mold fills their tiny spaces and can be impossible to remove completely. Source: EPA
- Check your work. You're done only when the water problem is fixed, there's no visible mold or musty smell, and the spot still looks dry a little while later. Source: EPA Stains can remain even after the mold is gone.
If it doesn't work
- Landlord ignoring a leak that keeps coming back? EPA says renters can contact local, state or federal health or housing authorities, including the state health department. Source: EPA See Your rights as a tenant.
- Musty smell but no visible mold? It may be hidden behind drywall or wallpaper, under carpet, or above ceiling tiles. Pulling off wallpaper can release a cloud of spores, so consider a professional. Source: EPA
- Mold near the heating or cooling vents? Don't run the system if you think it's contaminated. It could spread mold through the whole place. Source: EPA Tell your landlord.
- Mold keeps coming back in the shower? Run the fan or open a window, and clean more often. Source: EPA
- Thinking about a mold test? If you can see mold, testing usually isn't needed, and there are no federal limits to test against. Source: EPA
Good to know
Keep humidity down
Keep indoor humidity below 60 percent, ideally 30 to 50 percent. Vent the dryer and stove outside, use the air conditioner or a dehumidifier when needed, and run exhaust fans or open a window when you shower, cook or run the dishwasher. Source: EPA
Stop condensation
Open doors and windows when you can, use fans, raise the temperature a little, and insulate cold water pipes. Source: EPA
How it can affect you
For some people, mold causes a stuffy nose, sore throat, coughing or wheezing, burning eyes or a rash. People with asthma or mold allergies can react badly. Source: CDC Mold can irritate the eyes, skin, nose, throat and lungs even in people who aren't allergic. Source: EPA If you have health concerns, talk to a doctor before you clean.
A message to your landlord (made-up example)
"Hi, this is Jordan in 3B. There's a leak under the bathroom sink and a patch of mold about the size of a dinner plate on the cabinet floor. Photos attached. Can someone come fix the leak this week? I've put a towel down and I'm keeping the area dry until then."
Hiring help
If you hire someone, pick a contractor with mold experience, check references, and ask them to follow EPA's mold remediation guidance. Source: EPA
Sources
- U.S. Environmental Protection Agency A brief guide to mold, moisture and your home
- Centers for Disease Control and Prevention About mold and your health
- U.S. Environmental Protection Agency Mold
Lesson H3.4 · Last checked October 2, 2026 against the sources listed.
Find it online: