A little mold on a bathroom wall, a window sill or a cabinet back is common in Florida, and the EPA says you can usually clean it yourself if the area is less than about 10 square feet. This guide follows the EPA's home mold guidance step by step: what to buy, how to clean, what to throw away, and the points where you should stop and call a pro.
Stop and call a pro before you start if:
- The mold covers more than about 10 square feet (bigger than roughly a 3-by-3-foot patch). For more than that, the EPA points to its professional remediation guidance. In Florida, mold assessment and remediation over 10 square feet are licensed work when you hire someone, unless an exemption applies (s. 468.8411); homeowners working on their own home are exempt (s. 468.841).
- Sewage or floodwater caused it. The EPA says to "call in a professional who has experience cleaning and fixing buildings damaged by contaminated water." See our floodwater cleanup guide.
- You have asthma, a weakened immune system or other health concerns. The EPA says to "consult a health professional before starting cleanup," and that people with breathing problems or weakened immune systems should stay away from moldy sites.
- The mold is in your A/C system or ducts. The EPA says "Do not run the HVAC system if you know or suspect that it is contaminated with mold." Our advice: have a licensed HVAC contractor look at it.
- The home was built before 1978 and you'd be sanding or scraping paint. It may have lead-based paint; the EPA recommends testing first or hiring a lead-safe certified contractor.
- The ceiling is sagging, or water reached outlets or the electrical panel. Our advice: stay out of that area and call a licensed electrical contractor.
What you'll need
Safety gear (from the EPA's mold guide)
| Item | Why | Where to buy |
|---|---|---|
| N-95 respirator | The EPA says you may want to wear one to avoid breathing in mold or spores | Home Depot · Lowe's |
| Long gloves (to mid-forearm) | Keeps mold off your skin; the EPA says ordinary household rubber gloves work with water and mild detergent | Home Depot · Lowe's |
| Goggles without vent holes | Keeps spores out of your eyes | Home Depot · Lowe's |
Cleaning supplies
| Item | Why | Where to buy |
|---|---|---|
| Household detergent and a bucket | The EPA says to scrub hard surfaces with detergent and water | Home Depot · Lowe's |
| Stiff scrub brush and sponges | The EPA says to scrub mold off hard surfaces | Home Depot · Lowe's |
| Heavy plastic trash bags | For moldy materials that have to go | Home Depot · Lowe's |
| Fan or dehumidifier | Drying the area completely | Home Depot · Lowe's |
| Hygrometer (humidity meter) | Checking that indoor humidity stays below 60% | Home Depot · Lowe's |
Step by step
Step 1: Measure the moldy area
Use a tape measure. The EPA's do-it-yourself limit is about 10 square feet: if the mold covers more than about 10 square feet, or you find more once you start, stop here and see the box above. Our advice: take photos with the tape in view for your records.
Step 2: Find and fix the moisture
The EPA's first rule: "The key to mold control is moisture control." It also warns that if you clean the mold but don't fix the water problem, the mold will most likely come back. Our advice: look for the source (a dripping pipe, a leaking window, a roof leak or condensation). Plumbing and roof repairs go to a licensed plumber or roofer.
Step 3: Put on your gear
N-95 respirator, long gloves and goggles without vent holes, the gear the EPA lists for mold cleanup. Our advice: put it on before you start, keep it on until you're done, and keep children and pets out of the room.
Step 4: Scrub hard surfaces with detergent and water
The EPA says to "Scrub mold off hard surfaces with detergent and water, and dry completely."
About bleach: the EPA says using a biocide such as chlorine bleach "is not recommended as a routine practice during mold cleanup," because dead mold can still cause allergic reactions and has to be removed, not just killed. If you do use bleach, the CDC says to use no more than 1 cup of bleach in 1 gallon of water, and never mix bleach with ammonia or other cleaners: the EPA warns the fumes can be toxic. The EPA also says to always ventilate the area when using disinfectants or biocides.
Step 5: Bag what can't be cleaned
The EPA says absorbent or porous materials, "such as ceiling tiles and carpet, may have to be thrown away if they become moldy," because the mold may be "difficult or impossible to remove completely." Our advice: seal them in heavy plastic bags before carrying them through the house.
Step 6: Dry everything
Dry the area completely; fans and a dehumidifier help. The EPA says that if wet materials are dried within 24 to 48 hours of a leak, "in most cases mold will not grow." If you can already see mold, the EPA says to clean it first, then start the fans.
Step 7: Don't paint over it
The EPA says "Do not paint or caulk moldy surfaces," and to clean up the mold and dry the surface before painting, because paint applied over mold "is likely to peel."
Step 8: Check that it's done, and keep it dry
The EPA says the job isn't finished until the water or moisture problem is completely fixed, and that "Visible mold and moldy odors should not be present." Keep indoor humidity below 60 percent, ideally between 30 and 50 percent, and check it with a hygrometer.
How long it takes
The drying is what matters. The EPA says to dry water-damaged areas and items within 24 to 48 hours to prevent mold growth.
Stop and call a pro if, once you start, you find:
- Mold spreading past about 10 square feet, the EPA's do-it-yourself limit.
- Mold on the back of drywall or other hidden places; the EPA lists "the back side of dry wall" among spots where hidden mold grows.
- A moldy smell after cleaning and drying; the EPA says "Visible mold and moldy odors should not be present" when the job is done.
- Our advice: soft or rotted wood, or water damage around wiring.
If drywall, flooring or trim has to be replaced once the mold is handled and the leak is fixed, that's where we come in: see our storm and water damage repair service. We're a licensed general contractor, not a licensed mold assessor or remediator. For larger mold jobs, read when you need a licensed mold pro.
Frequently asked questions
How big a mold patch can I clean myself?
The EPA says that if the moldy area is less than about 10 square feet, roughly a 3-by-3-foot patch, you can usually handle the job yourself.
What should I clean mold with?
The EPA says to scrub mold off hard surfaces with detergent and water and dry them completely. It doesn't recommend bleach as a routine practice.
Can I paint over mold?
No. The EPA says not to paint or caulk moldy surfaces; clean and dry them first, because paint over mold is likely to peel.
Do I need to test the mold first?
Usually not. The EPA says that if visible mold growth is present, sampling is unnecessary in most cases.
Sources
- U.S. EPA: A brief guide to mold, moisture and your home
- U.S. EPA: Mold cleanup in your home
- U.S. EPA: Flood cleanup to protect indoor air and your health
- CDC: Mold clean up guidelines
- U.S. EPA: Lead-safe renovations for DIYers
- Florida Statutes 468.8411: Mold-related services definitions
- Florida Statutes 468.841: Exemptions