How to get rid of mold yourself (and when you should not)

How big of a mold problem can you clean yourself?

EPA’s rule of thumb is about 10 square feet. In EPA’s words, if the moldy area is “less than roughly a 3 ft. by 3 ft. patch,” in most cases you can handle the job yourself. That is enough for a typical patch on a bathroom ceiling, a window frame or the back of a closet wall.

Size is not the only test. EPA and CDC add several conditions that make DIY a poor choice even for a small area:

• There has been a lot of water damage, such as a burst pipe or roof leak.
• The water was sewage or other contaminated water.
• Mold is in the heating and cooling system or near its air intake.
• You have health concerns. CDC says people with mold allergies, immune suppression, lung disease or asthma should not do the cleanup.

Measure the total of all patches, not just the largest one. If you are close to 10 square feet, or you think the mold continues behind the surface, read mold removal vs remediation before you start. For broader background on identification, health and cost, see the mold hub.

What should you do before you start cleaning?

Fix the water first. EPA’s first cleanup step is to fix plumbing leaks and other water problems as soon as possible. If the leak keeps going, the mold comes back. For a roof leak, a slow drain or condensation, a temporary stop is better than nothing while you schedule the repair.

Then set up the room:

• Close interior doors to keep dust in the work area.
• Open a window to the outside if you can.
• Move or cover nearby belongings with plastic.
• Turn off central air if its vents are in the room, and cover the supply and return vents with plastic and tape.
• Lay plastic on the floor below the work area.

Do not point a fan at the mold while you work. EPA lists using fans to dry items among the actions likely to stir up mold and raise exposure. Fans help afterward, once the mold is gone.

Photograph the damage before you clean, with dates. If you later file an insurance claim or report the problem to a landlord, those photos are your record. Our emergency mold steps cover the first 48 hours in more detail.

What protective gear do you need?

CDC’s minimum for mold cleanup is at least a NIOSH Approved N95 respirator, protective gloves (non-latex, vinyl, nitrile or rubber) and goggles that provide complete eye protection.

EPA adds detail. Gloves that reach the middle of the forearm are best. Ordinary household rubber gloves are fine with plain water and mild detergent, but if you use bleach or a strong cleaner, choose natural rubber, neoprene, nitrile, polyurethane or PVC. Goggles should have no ventilation holes. A respirator only works if it fits, so follow the fit instructions that come with it. EPA put N-95 respirators at about $12 to $25 in its home guide.

Wear old clothes you can wash right away in hot water, or disposable coveralls. Take them off before you walk through the rest of the house.

People who should not do the work at all, according to CDC: those with mold allergies, those with immune suppression or underlying lung disease, and those with chronic respiratory disease such as asthma. Our mold cleanup PPE guide covers fit, respirator types and disposal.

How do you clean mold off hard surfaces?

EPA’s method is simple: “Scrub mold off hard surfaces with detergent and water, and dry completely.” It works on tile, glass, metal, plastic, sealed countertops, finished wood and similar surfaces.

1. Mix a bucket of warm water and a household detergent or dish soap.
2. Wet the surface first. Dry brushing throws spores into the air.
3. Scrub with a stiff brush or sponge until no mold is visible.
4. Wipe with clean water and a fresh rag.
5. Dry the surface completely with towels, then a fan pointed at it once cleaning is done.
6. Put used rags and sponges in a plastic bag, seal it and throw it out.

EPA warns that mold can leave stains and cosmetic damage, and “it may not be possible to clean an item so that its original appearance is restored.” A faint stain on grout or wood after cleaning is not proof that mold remains, but fuzzy growth or a musty smell means you are not done.

EPA does not recommend bleach as a routine part of cleanup. If you choose to use it, CDC’s limit is no more than 1 cup of bleach per gallon of water, never mixed with ammonia or other cleansers. Our what kills mold page compares bleach, vinegar, hydrogen peroxide and commercial products.

Which surfaces can you clean, and which should you throw away?

The dividing line is whether the material is porous. EPA explains that mold “can grow on or fill in the empty spaces and crevices of porous materials, so the mold may be difficult or impossible to remove completely.”

For drywall, see mold on drywall. For anything expensive or sentimental, EPA suggests consulting a restoration specialist before you clean or discard it.

How do you remove moldy materials without spreading spores?

Moldy porous items come out in plastic. EPA’s professional guidance is to seal moldy materials in plastic bags before carrying them out of the work area, and to wrap large items in plastic sheeting sealed with tape. That keeps spores from shaking loose as you walk through the house.

Some tips for small DIY jobs:

• Mist the moldy material lightly with water before you handle it to keep dust down.
• Cut drywall or carpet into pieces small enough to fit in a bag.
• Seal the bag inside the room, then carry it straight outside.
• EPA says bagged mold debris can usually go out as ordinary construction waste. Check your local hauling rules.

Be careful with older homes. EPA says the federal lead paint rule generally does not apply to homeowners working in their own pre-1978 home, but it does apply if you rent out the home, run a childcare center there or renovate it to sell. EPA still recommends lead-safe practices. In an older home, do not cut, sand or tear any material you suspect contains asbestos. EPA says removal must be done only by a trained and accredited asbestos professional.

How do you know the mold is gone?

EPA gives a short test for homeowners:

• The water or moisture problem is completely fixed.
• Visible mold and moldy odors are gone. Stains alone may remain.
• When you check again shortly after cleanup, there are no signs of new water damage or mold growth.
• People can use the room without health complaints.

EPA calls this “a judgment call.” There is no number to hit. CDC does not recommend routine mold testing, and EPA notes there are no federal limits for mold to test against. A test kit cannot tell you whether a small, cleaned area is now safe.

Look again a week later and after the next few showers, storms or humid days. If mold returns in the same spot, the moisture source was not fully fixed, or the growth reaches deeper than you could see. That is the point to bring in a professional.

How do you stop mold from coming back?

Keep things dry. EPA says that if wet or damp materials are dried within 24 to 48 hours after a leak or spill, in most cases mold will not grow.

EPA’s humidity target is below 60 percent relative humidity, ideally between 30 and 50 percent. CDC recommends no higher than 50 percent, all day long. A hygrometer, which EPA says costs about $10 to $50, shows where you stand.

Other EPA prevention steps:

• Run the bathroom fan or open a window when you shower. CDC recommends exhaust fans in bathrooms and kitchens that vent outside.
• Vent clothes dryers to the outside.
• Keep air conditioner drip pans clean and drain lines flowing.
• Insulate cold water pipes and other surfaces where condensation forms.
• Use air conditioning or a dehumidifier when needed.
• Clean gutters and slope soil away from the foundation.

Renters should report leaks and moisture problems to the landlord right away. EPA says that if persistent water problems are not addressed, you can contact local or state health or housing authorities. For more, see mold prevention.