How to Remove Black Mold Safely: Step by Step, and When to Call a Professional

Black mold is removed the same way as any other mold. The CDC says all molds should be treated the same with respect to health risks and removal, so the question is not what color it is but how big the area is, what it is growing on, and whether the water that feeds it has been fixed. Small patches on hard surfaces are often a job you can do yourself. Larger areas and mold inside walls are not.

This guide walks through how to remove black mold safely, what products actually do, and where the line is between a DIY job and a professional one. For background on what black mold is, see our black mold guide.

Before you start: is this a DIY job?

Answer these first:

• How big is it? The EPA says homeowners can often clean areas smaller than about 10 square feet, roughly a 3 by 3 foot patch.
• What is it growing on? Hard surfaces such as tile, glass, metal, and sealed wood can be cleaned. Porous materials such as drywall, ceiling tiles, carpet, and insulation usually have to be removed.
• Is the water fixed? If the leak or humidity problem is still active, the mold will return.
• Where did the water come from? Mold from sewage or floodwater calls for a professional.
• Is it in the air conditioning system? The EPA advises not running a system you suspect is contaminated, and cleaning it is a professional job.
• Who lives here? Anyone with asthma, mold allergies, chronic lung disease, or a weakened immune system should stay away from the work and should not do it.

If any answer points to a professional, see DIY vs. professional mold removal.

What you need

• An N-95 respirator
• Long gloves, such as rubber or nitrile
• Goggles without ventilation holes
• Detergent, water, a scrub brush, and disposable rags
• Heavy plastic bags for moldy materials and used rags
• A fan to exhaust air out a window, and a dehumidifier or fans for drying

Step by step

1. Fix the moisture source. Repair the leak, clear the drain, or lower the humidity first.
2. Isolate the area. Close the door, keep people and pets out, and if possible put a fan in the window blowing out. Close air conditioning vents in the room so spores are not pulled into the system.
3. Put on your protective gear.
4. Keep dust down. Lightly misting the moldy surface with water before you work helps keep spores from becoming airborne.
5. Scrub hard surfaces. Use detergent and water and a brush, then wipe clean.
6. Remove porous materials that are moldy. Cut out moldy drywall, carpet, or ceiling tile, and bag it in the room before carrying it out.
7. Dry everything. The EPA advises drying water-damaged areas within 24 to 48 hours.
8. Clean up. Wipe nearby surfaces with a damp cloth, bag the rags, and wash your work clothes separately.
9. Check the result. No visible mold, no mold-damaged material, no musty smell, and no remaining moisture.

What kills black mold? Bleach, vinegar, and other products

The EPA does not recommend biocides such as bleach as a routine part of mold cleanup. Two reasons matter: dead mold can still cause allergic reactions, so killing it without removing it is not enough; and no product reaches reliably into porous materials like drywall and wood.

If you do use bleach on a hard surface, the CDC's cleanup guidance calls for a solution of no more than 1 cup of bleach per gallon of water, with good ventilation. Never mix bleach with ammonia, vinegar, or other cleaners, because the fumes can be toxic.

Vinegar and other household products are popular, but no product makes it safe to leave moldy drywall, carpet, or insulation in place. The part that matters is physical removal and drying.

Removing black mold from specific surfaces

• Tile, grout, and caulk: scrub with detergent and water; replace caulk that stays stained. See black mold in the shower.
• Painted drywall: light surface spots can sometimes be wiped off. If the stain remains or the drywall is soft, it needs to be cut out. See mold behind drywall.
• Wood: surface growth on sealed or raw wood can be cleaned and, on raw framing, lightly sanded while wearing a respirator. Wood that is soft or rotted is replaced.
• Carpet: wall-to-wall carpet with mold growth is usually removed. See mold under carpet.
• Concrete and block: scrub with detergent and water and dry; deal with the moisture coming through.

When to stop and call a professional

• The area turns out to be larger than about 10 square feet
• You find mold on the back of drywall, in insulation, or under flooring
• The mold is in the air conditioning system or ducts
• The water came from a flood or sewage
• The smell persists or the mold returns within weeks
• Anyone in the home develops symptoms or is at higher risk

Professionals use containment, HEPA air filtration, and controlled removal so spores do not spread. See what is mold remediation.

What it costs

DIY removal of a small area costs little more than protective gear and supplies. Professional remediation of a small area typically runs about $500 to $1,500, per HomeGuide, and national cost guides put typical jobs at about $1,100 to $3,400. See our mold remediation cost guide.

Next step

If you own your home and the black mold is larger than a small patch, inside walls, or keeps coming back, call the number on this page to be connected with an independent local mold removal company.