Recommended Steps for Mold Cleanup From Flooded Homes

We are recommending the following steps for contractors and homeowners involved in clean-up efforts:

1.   Prepare the Site

• Have the electrical system checked by a electrician and use only if safe.  If the electrical system was flood damaged, set up generators outside of home. Indoor use of generators will create carbon monoxide hazards.
• Open doors and windows for 30 minutes before working in the home to reduce odor levels and allow for dilution of airborne contaminants.
• Contact your utility and remain out of the home if there is an odor of natural gas. Turn off central air heating/air conditioning system until it has been cleaned or replaced.

 2.   Debris Removal

• Remove all moldy materials and any items that became wet during the flood and cannot be cleaned (e.g. carpets, bedding, couches, electronics that were submerged, flood damaged wallpaper, wallboard, ceiling tile and insulation).
• To access wallboard, wood trim should be removed and discarded or stored off-site for cleaning, if historic. 
• Pots, dinnerware, buckets and anything else that filled with floodwaters need to be removed carefully. They may contain dangerous bacteria.

 3.   HEPA Vacuum

• After furnishings and contaminated debris are removed to storage or discarded, remove mold growth on exposed framing members with dry bristle brushing and HEPA vacuuming simultaneously.
• Reclean any remaining visible areas of growth following this method. Provide the necessary time for dust and spore settling between cleaning rounds. In homes where studs are already fairly dry, we recommend only the dry cleaning/HEPA vacuum step for studs.

 4.   Wet Cleaning

• On wood surfaces such as walls, ceilings, cabinets, floors, where visible mold growth cannot be removed with dry cleaning, damp wipe the surfaces using a non-phosphate detergent and water. Starting at the ceiling, wipe with sponge mops and hand sponges until all visible dirt and stains are removed.
• During damp wiping, minimize the amount of water used to avoid saturating building materials. If wood does become saturated, allow it to dry before next steps.  Failure to allow saturated surfaces to adequately dry may result in water damage (wood rot) or new mold growth.

 5.   Sanitize

• For hard surfaces that will remain in the home, use a disinfectant to kill any remaining mold and other contaminants. Damp wipe all accessible surfaces including tubs, bath and kitchen fixtures, non-wood cabinets and countertops, and vinyl/tile floors with a solution of 1 cup bleach to 1 gallon of water plus non-phosphate detergent.  

 6.   Borate Treatments

• Using a moisture meter, measure wood surfaces for moisture content.  Once moisture content is less than 20%, it is ready for application of a borate solution. 
• Wash or mist the open wall cavities with a borate solution like TermitePrufe or BoraCare prepared to the manufacturer's specifications for wood fungi. These products are more expensive than using household bleach, however borate solutions are not corrosive or whiteners, and are therefore safer to use around metals and valuable wood products. Borates are also more effective at penetrating wood and killing all parts of the fungi. These products can be applied with a paint brush, paint roller, trigger spray bottle or from a tank sprayer. A pesticide applicator's license may be required if these treatments are done by someone other than the owner of the home or building.

 7.   Final Drying

• Open all windows for at least seven dry-weather days after this treatment so the house can dry out.
• If the home must be secured or there is inclement weather, use mechanical dehumidification to dry the home.  Options include a dehumidifier that empties into the toilet or a clean window air conditioner. 
• Try to avoid contaminating the home with mold or debris from the outside of the home. For example, wear disposable booties over shoes when entering the home.