How to clean mold?

Why are molds a concern?
Is there a mold problem?
How can you tell if it is mold?
How much mold is growing?
How to clean mold?
Dealing with an ongoing mold problem.
Preventing mold.
Mold-Proofing your home, basement.
Mold-Proofing your home, bathrooms, kitchen, laundry.
Mold-Proofing your house, closets and bedrooms, exterior.
Should I have my house air tested for mold?
The air feels dry, can I humidify?
What advantages do HEPA vacuums provide?
Is vacuuming with a HEPA or externally exhausted vacuum cleaner recommended for serious mold problems only?
Where do you find a HEPA vacuum cleaner?

When should you seek professional help?

You may need professional help when:

• There is a lot of mold
• The home is very damp and moist
• Mold comes back after repeated cleaning
• A family member suffers from asthma or respiratory problems or other health problems that appear to be aggravated inside the home

How do you get professional help?

Contact your local CMHC office for a list of individuals who have completed the CMHC Residential Indoor Air Quality Investigator program. A trained IAQ investigator, who operates a private business and sells his/her services, examines the indoor air quality of your home and documents your concerns. He/she identifies the problems, finds their sources and suggests solutions in a written report. Recommendations are provided to you in an action plan that consists of various options to improve the indoor air quality in your home.

How to clean up mold problems

"Small areas" of mold can be cleaned with a detergent solution.
Wear a mask, safety goggles and rubber gloves.
Seek professional help if there is a lot of mold or if mold comes back after cleaning.

Bleach is NOT recommended

The presence of organic (humic) materials, the pH (acidity/alkalinity) of the water, the surface material and contact time affect the effectiveness of bleach for disinfection. Since these factors are not generally controlled, bleach cannot be relied upon for disinfection. The most compelling reason for advising against bleach is that fumes are harmful but in addition, overuse of bleach will result in increased releases of chlorinated effluents which can be harmful to the environment.

"Small area" clean-up
You can clean up "small areas" of mold (fewer than three patches, each smaller than a square meter) yourself. The minimum protective wear needed are:

• safety glasses or goggles;
• a disposable dust mask (3M 8210 or equivalent)
• household rubber gloves.

Infants and other family members with asthma, allergies or other health problems should not be in the work area or adjacent room during the cleaning.

Washable surfaces:

Scrub with an unscented detergent solution; then sponge with a clean, wet rag and dry quickly.

Using an unscented detergent will make it easier for you to detect residual moldy odours.

Moldy drywall:

Clean the surface with a damp rag using baking soda or a bit of detergent. Do not allow the drywall to get too wet.

Mold that comes back after cleaning is usually an indication that a source of moisture has not been removed. Seek professional help from a trained IAQ investigator.

"Moderate area" clean-up

Clean "moderate areas" of mold, but wear proper protective equipment and follow precautions.
Seek professional help if there is a lot of mold or if mold comes back after cleaning.
If you follow the proper procedures and use the proper protective equipment, you can clean up "moderate areas" of mold. "moderate areas" means more than 3 patches of mold, each smaller than one square meter, or one or more isolated patches larger than one square meter but smaller than 3 square meters (size of a 4 x 8 foot sheet of plywood).

General cleaning

Vacuum surfaces with a vacuum cleaner which has a High Efficiency Particulate Air (HEPA) filter or is externally exhausted. Scrub or brush the moldy area with a mild unscented detergent solution. Rinse by sponging with a clean, wet rag. Repeat. Dry quickly. HEPA vacuum the surfaces that were cleaned as well as surrounding areas.

Cleaning wood surfaces

Vacuum loose mold from wood surfaces using a HEPA or externally exhausted vacuum. Try cleaning the surface of the wood with detergent and water. Rinse with a clean, damp rag and dry quickly. If the staining does not come off, sand and vacuum the surface of the wood with a vacuum/sander combination. It is important to vacuum at the same time to prevent mold spores from being dispersed into the air. Note that wood affected by rot may need to be replaced.

Cleaning concrete surfaces

Vacuum the concrete surfaces to be cleaned with a HEPA or externally exhausted vacuum cleaner. Clean up surfaces with detergent and water. If the surfaces are still visibly moldy, use TSP (trisodium phosphate). Dissolve one cup of TSP in two gallons of warm water. Stir for two minutes. Note: TSP must not be allowed to come in contact with skin or eyes. Saturate the moldy concrete surface with the TSP solution using a sponge or rag. Keep the surface wetted for at least 15 minutes. Rinse the concrete surface twice with clean water. Dry thoroughly, as quickly as possible.

Moldy drywall

The paper facings of gypsum wallboard (drywall) grow mold when they get wet or repeatedly wet and don't dry quickly. Cleaning with water containing detergent not only add moisture to the paper but also can eventually damage the facing. If the mold is located only on top of the painted surface, remove it by general cleaning (see above). If the mold is underneath the paint, the moldy patch and other moldy material behind it are best cut out and the surrounding areas also cleaned. This should be done by a mold clean-up contractor. New materials may become moldy if the moisture entry has not been stopped. If this is the case, replacement of the materials should be deferred until the source of the moisture is corrected. The affected areas should be temporarily covered with plastic sheeting and sealed at the edges.

Any areas that show new patches of mold should be cleaned promptly.