How do you get rid of black mold?

Key facts

• EPA, moldy-area size under which in most cases you can handle the job yourself (national): "If the moldy area is less than about 10 square feet (less than roughly a 3 ft. by 3 ft. patch), in most cases, you can handle the job yourself"

  Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.

• EPA, indoor humidity target (national): "If possible, keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity."

  Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

• EPA, drying window after a leak (national): "If wet or damp materials or areas are dried 24-48 hours after a leak or spill happens, in most cases mold will not grow."

  Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

• EPA mold course, job size bands (national): "Remediations generally can be divided into small (less than 10 square feet of mold), medium (10-100 square feet of mold) and large jobs (more than 100 square feet of mold)."

  Source: EPA, Mold Course Chapter 4, read 24 October 2026.

• EPA remediation guide, containment range (national): "Limited containment is generally recommended for areas involving between 10 and 100 square feet (ft2) of mold contamination."

  Source: EPA, Mold Remediation in Schools and Commercial Buildings, Chapter 3, read 24 October 2026.

• EPA remediation guide, minimum respirator when cleaning a small area (national): "Minimum: When cleaning up a small area affected by mold, you should use an N-95 respirator."

  Source: EPA, Mold Remediation in Schools and Commercial Buildings, Chapter 3, read 24 October 2026.

• EPA mold course, bags for discarded materials (national): "Mold-contaminated building materials that cannot be salvaged should be double-bagged in 6-mil or thicker polyethylene bags."

  Source: EPA, Mold Course Chapter 4, read 24 October 2026.

• Minnesota Department of Health, winter humidity range (Minnesota): "To keep indoor surfaces as dry as possible, try to maintain the home's relative humidity between 20-40 percent in the Winter and less than 60 percent the rest of the year."

  Source: Minnesota Department of Health, Mold in Homes, read 24 October 2026.

How do you permanently get rid of black mold?

EPA says that if there is mold growth in your home, you must clean up the mold and fix the water problem, and that if you clean up the mold, but don't fix the water problem, then, most likely, the mold problem will come back. It also says it is impossible to get rid of all mold and mold spores indoors, and that indoor mold growth can and should be prevented or controlled by controlling moisture indoors. EPA gives a humidity target: "If possible, keep indoor humidity below 60 percent (ideally between 30 and 50 percent) relative humidity." After a leak, EPA says that if wet or damp materials or areas are dried 24-48 hours after a leak or spill happens, in most cases mold will not grow.

Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026: "If you clean up the mold, but don't fix the water problem, then, most likely, the mold problem will come back." "Run the bathroom fan or open the window when showering."

Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

Minnesota Department of Health, Mold in Homes, read 24 October 2026, on its winter range: "To keep indoor surfaces as dry as possible, try to maintain the home's relative humidity between 20-40 percent in the Winter and less than 60 percent the rest of the year."

Source: Minnesota Department of Health, Mold in Homes, read 24 October 2026.

How toxic is black mold in a house?

Florida's health department says all indoor mold growth should be removed promptly, no matter what type(s) of mold is present, or whether or not it can produce mycotoxins. EPA's mold course says to remember that mold comes in many colors, not just black, and the Minnesota Department of Health says any mold indoors is a problem. On health, EPA says molds produce allergens (substances that can cause allergic reactions), irritants, and in some cases, potentially toxic substances (mycotoxins), while Florida's health department says the toxic effects of certain molds are not well understood. On testing, EPA says that in most cases, if visible mold growth is present, sampling is unnecessary, and New York's health department says mold testing is not recommended. EPA: "If you have health concerns, consult a health professional before starting cleanup."

Source: Florida Department of Health, Mold, read 24 October 2026.
Source: EPA, Mold Course Chapter 3, read 24 October 2026.
Source: Minnesota Department of Health, Mold in Homes, read 24 October 2026.
Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.
Source: New York State Department of Health, mold guidance, read 24 October 2026.
Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.

Florida Department of Health, Mold, read 24 October 2026: "The toxic effects of certain molds are not well understood, and are currently a controversial topic in the medical and scientific community."

Source: Florida Department of Health, Mold, read 24 October 2026.

What kills black mold completely, and does bleach work?

EPA says that in most cases, it is not possible or desirable to sterilize an area, and that dead mold may still cause allergic reactions in some people, so it is not enough to simply kill the mold, it must also be removed. EPA says the use of a chemical or biocide that kills organisms such as mold (chlorine bleach, for example) is not recommended as a routine practice during mold cleanup, and Florida's health department says using bleach or other chemicals to kill indoor mold growth is not needed in most cases. If you choose to use disinfectants or biocides, EPA says to always ventilate the area and exhaust the air to the outdoors, and to never mix chlorine bleach solution with other cleaning solutions or detergents that contain ammonia.

Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.
Source: Florida Department of Health, Mold, read 24 October 2026.

New York State Department of Health, mold guidance, read 24 October 2026, on places that cannot be kept dry: "In areas where it is impractical to eliminate the moisture source, diluted chlorine bleach (one cup of bleach in five gallons of water) can be used to keep mold growth under control."

Source: New York State Department of Health, mold guidance, read 24 October 2026.

Can you get rid of basement mold yourself?

EPA's size line answers it: if the moldy area is less than about 10 square feet, in most cases, you can handle the job yourself. For wet carpet, concrete and drywall, EPA's mold course gives drying steps. It says that to dry carpet and backing within 48 hours, remove water with a wet vacuum, pull the carpet and pad off the floor and dry them using a fan to blow air over them. It says water can be removed from concrete or cinder block surfaces with a water-extraction vacuum, and that drywall may be dried in place if there is no obvious swelling and the seams are intact; otherwise, removal is necessary. It also says wet vacuums should be used only when materials are still wet, otherwise they may spread mold spores. Florida's health department says that when water stands for even 24 hours, common molds can take hold.

Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.
Source: EPA, Mold Course Chapter 4, read 24 October 2026.
Source: Florida Department of Health, Mold, read 24 October 2026.

EPA, Mold Course Chapter 4, read 24 October 2026: "Drywall, also known as gypsum board or gypsum wallboard, may be dried in place if there is no obvious swelling and the seams are intact. Otherwise, removal is necessary."

Source: EPA, Mold Course Chapter 4, read 24 October 2026.

Which black mold jobs can you handle, and which need a pro?

Treat the patch size as the first fork and the water source as the second. A patch under about 10 square feet, with its leak already fixed, sits inside EPA's small-job line; hidden mold and sewage water fall outside it. Work in this order, and stop at any step that turns up more mold or more water than you expected. This is practical reasoning, not legal advice and not a finding from any agency.

Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.
Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

1. Measure the visible patch. Washington's health department: "A small area is less than about ten square feet, or a patch three feet by three feet square."

   Source: Washington State Department of Health, Mold, read 24 October 2026.

2. Find and fix the water problem first. EPA: "Fix plumbing leaks and other water problems as soon as possible."

   Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.
   Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

3. Put on protection before you touch it. EPA: "Minimum: When cleaning up a small area affected by mold, you should use an N-95 respirator." EPA also says: "Long gloves that extend to the middle of the forearm are recommended." "Goggles that do not have ventilation holes are recommended."

   Source: EPA, Mold Remediation in Schools and Commercial Buildings, Chapter 3, read 24 October 2026.
   Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

4. If you suspect the heating and cooling system is contaminated, leave it off. EPA: "Do not run the HVAC system if you know or suspect that it is contaminated with mold - it could spread mold throughout the building."

   Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.

5. Scrub hard surfaces. Minnesota's health department: "Scrub surfaces with a stiff brush, hot water and household detergent. The goal is to remove the physical mold growth."

   Source: Minnesota Department of Health, Mold in Homes, read 24 October 2026.

6. Bag building materials that cannot be salvaged. EPA's mold course: "Mold-contaminated building materials that cannot be salvaged should be double-bagged in 6-mil or thicker polyethylene bags."

   Source: EPA, Mold Course Chapter 4, read 24 October 2026.

7. Dry the area, then deal with your cleaning supplies. EPA: "Dry all items completely." Florida's health department: "Throw away any sponges or rags used to clean mold."

   Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.
   Source: Florida Department of Health, Mold, read 24 October 2026.

8. Wait to paint. EPA: "Do not paint or caulk moldy surfaces." "Paint applied over moldy surfaces is likely to peel."

   Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.

Hire a pro when one of these agency lines fits your job:

• The patch is bigger than the small-job line. Washington's health department: "If you have a lot of mold damage (more than ten square feet) consider hiring a cleaning professional."

  Source: Washington State Department of Health, Mold, read 24 October 2026.

• The water was sewage. EPA: "If the water and/or mold damage was caused by sewage or other contaminated water, then call in a professional who has experience cleaning and fixing buildings damaged by contaminated water."

  Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.

• You suspect hidden mold. EPA: "If you believe that you may have a hidden mold problem, consider hiring an experienced professional."

  Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

• You cannot use a respirator or are sensitive to mold. Minnesota's health department: "Review your health status, and if you cannot use a respirator or have sensitivity to mold, consider hiring a mold remediation professional."

  Source: Minnesota Department of Health, Mold in Homes, read 24 October 2026.

What to ask for in writing if you hire:

• How and when the water or moisture source will be fixed.

  Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

• The measured size of the moldy area and the containment planned for it, against EPA's small (less than 10 square feet), medium (10-100) and large (more than 100) remediation bands.

  Source: EPA, Mold Course Chapter 4, read 24 October 2026.
  Source: EPA, Mold Remediation in Schools and Commercial Buildings, Chapter 3, read 24 October 2026.

• Which porous materials come out, and how they are bagged and carried out.

  Source: EPA, Mold Course Chapter 4, read 24 October 2026.
  Source: New York State Department of Health, mold guidance, read 24 October 2026.

• The company's experience with mold. EPA: "If you choose to hire a contractor (or other professional service provider) to do the cleanup, make sure the contractor has experience cleaning up mold."

  Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.

• Whether any bleach, other biocide or ozone is planned, and why.

  Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.
  Source: Minnesota Department of Health, Mold in Homes, read 24 October 2026.

What should you look for before calling the job done?

Use EPA's own finish line rather than how the wall looks after one scrub, and judge the result by moisture, smell and regrowth. EPA: "Please note that mold may cause staining and cosmetic damage."

Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

1. The water or moisture problem is fixed. EPA: "You must have completely fixed the water or moisture problem before the cleanup or remediation can be considered finished."

   Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

2. No visible mold and no moldy smell remain. EPA: "Visible mold and moldy odors should not be present."

   Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

3. A humidity meter reads inside EPA's humidity target.

   Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

4. Moldy porous items were dealt with. EPA: "Absorbent or porous materials, such as ceiling tiles and carpet, may have to be thrown away if they become moldy."

   Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.

5. Nothing was painted or caulked over mold.

   Source: EPA, Mold Cleanup in Your Home, read 24 October 2026.

6. A return visit shows no regrowth. EPA: "You should have revisited the site(s) shortly after cleanup and it should show no signs of water damage or mold growth."

   Source: EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026.

Who sees your contact details when you post on InstaBids?

Contact details stay hidden until the homeowner picks a contractor and they confirm the connection.

Source: InstaBids process and privacy, live-page excerpts, read 24 October 2026.

Sources for the facts on this page

• EPA, Mold Cleanup in Your Home, read 24 October 2026
• EPA, A Brief Guide to Mold, Moisture and Your Home, read 24 October 2026
• EPA, Mold Course Chapter 3, read 24 October 2026
• EPA, Mold Course Chapter 4, read 24 October 2026
• EPA, Mold Remediation in Schools and Commercial Buildings, Chapter 3, read 24 October 2026
• Minnesota Department of Health, Mold in Homes, read 24 October 2026
• New York State Department of Health, mold guidance, read 24 October 2026
• Washington State Department of Health, Mold, read 24 October 2026
• Florida Department of Health, Mold, read 24 October 2026
• InstaBids process and privacy, live-page excerpts reviewed 24 October 2026.