Mold Removal

What are some initial steps to prepare for mold remediation?


Basement Mold.
Image Credit: Phillip Bouton

Determine the source of the mold. Fix any leaks or sources of moisture before attempting to remove the mold. If you can’t determine the source of the mold or the mold is in a hidden or inaccessible location (such as an attic crawl space), you may need to hire a mold inspector.

Assess the size of the mold or moisture problem and the type of materials affected. Is it something you can handle on your own or do you need to call a mold remediator or contractor? If the size of the moldy area is less than 10 square feet (approx. a 3 feet x 3 feet patch), the EPA suggests a nonprofessional can handle it. If over 10 square feet, consider hiring a professional mold remediator and consult the EPA’s Mold Remediation in Schools and Commercial Buildings.

If the air conditioning and heating ducts may be involved, see the EPA’s Should You Have the Air Ducts in Your Home Cleaned?

If sewage or other contaminated water caused the mold damage, hire a professional mold remediator.

Consider any health concerns you or your family may have prior to beginning work and talk to your doctor, if needed, before starting remediation.

What are some effective cleanup methods?

Wet vacuum: Use a vacuum cleaner designed to collect water and remove water from floors, carpets and hard surfaces. It’s important to remove all moisture within a 24 to 48 hour period to prevent the growth of mold.

Damp wipe: Scrub mold off hard surfaces with water and detergent and dry completely. The EPA does not recommend the use of bleach. However, other sources suggest the limited use of bleach (one cup per gallon of water) is acceptable. Bleach, by itself, does not remove mold. Removing the mold by scrubbing it off surfaces is required.

Discard: Throw out damaged materials. It’s important to double bag the moldy materials in plastic sheeting and seal to contain the spores.

HEPA Vacuum: A HEPA vacuum is recommended for the final cleanup after the moldy area has been thoroughly dried and all damaged materials have been removed. Dispose of the filter and contents of the vacuum in well-sealed plastic bags.

Homes that have been flooded may pose unique challenges. See the EPA’s Flood Cleanup and the Air in Your Home. See also the EPA’s Fact Sheet, Flood Cleanup: Avoiding Indoor Air Quality Problems.

For detailed information on these methods, see Additional Resources.

Are there new evidence-based techniques for mold cleanup?

Three recent studies tested different approaches to clean up:

Tea tree oil was found to be the most effective antifungal agent in a study that compared five agents: Cavicide, Virkon, 70% ethanol, vinegar and a plant-derived compound (tea tree (Melaleuca alternifolia) oil) tested in both a liquid and vapour form. See An Evaluation of Antifungal Agents for the Treatment of Fungal Contamination in Indoor Air Environments, International Journal of Environmental Residential Public Health, June 2015.

Steam-vapor was significantly better than high-flow hot water extraction and hot water and detergent in a study evaluating the growth and removal of fungi on wetted carpet. See Mold Management of Wetted Carpet, Journal of Occupational Environmental Hygiene, 2014.

No statistically significant difference was found in the efficacy for reducing mold in carpet between vacuuming, steam-vapor, Neem oil (tree tree oil) and benzalkonium chloride (a quaternary ammonium compound). However, the steam-vapor treatment was more effective in killing dust mites and denatured dust mite allergen in the laboratory environment than the other treatments. See Inactivation of Dust Mites, Dust Mite Allergen and Mold from Carpet. Journal of Occupational Environmental Hygiene, 2014.

How can I protect myself from mold and mold spores during remediation?

  • An N-95 respirator ($12-25) is recommended to protect from inhaling mold, mold spores and dust. It will filter out 95% of the particulates in the air.
  • Wear disposable protective clothing (paper overalls, head and shoe coverings).
  • Wear long gloves to protect your skin. If using detergent, household rubber gloves may be used but if using bleach, purchase gloves made from natural rubber, neoprene or nitrile.
  • To protect eyes, wear goggles or a full-face respirator.
  • Contain the work site using polyethylene sheeting attached to floors with duct tape. Cover all supply and air vents and doors to prevent mold spores from moving to other parts of your home. An exhaust fan ducted to the outdoors can be used for small DIY jobs.

Additional Resources

Tips for Hiring a Mold Remediation Contractor/Consultant, Wisconsin Department of Health Services
Creating a Healthy Homes: A Field Guide for Cleaning Up Flooded Homes, Enterprise Community Partners and the National Center for Healthy Housing
Mold Remediation Guidelines, NC State University

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