by Shane Henson — September 30, 2013—Catastrophic floods can cause more than just widespread damage to facilities; they often lead to mold that inevitably adds to the cost of repairing a facility. To assist facilities professionals, the Healthy Facilities Institute (HFI), Healthy House Institute (HHI), and The Institute of Inspection, Cleaning and Restoration Certification (IICRC) recently outlined Five Steps to Prevent Mold Growth after a Catastrophic Flood:
Step One: Check it out!: Once a building is flooded from a river, lake, stream, hurricane or rainstorm, inspecting and documenting damage is very important for several reasons, including insurance and tax purposes. Electrical, gas, structural, and other safety hazards present must be eliminated before assessing physical damage to the building and contents.
Once health and safety hazards have been eliminated, inspect the building and all contents. Generally, the rule of thumb is that everything below the water line gets thrown out. Building materials and contents above the water line should be inspected for discoloration, odor, and damage.
Step Two: Get it out!: Extract standing water with a pump or wet vacuum from slabs, basements, crawlspaces, heating systems, and anywhere water could be sitting. Shovel or flush out remaining silt and sand with water.
Next, remove all wallboard material (e.g., plaster, drywall, paneling), finished flooring (e.g., carpet, hardwood, vinyl flooring), insulation, and any other wet materials that are below the water line. Remove contents damaged by floodwater. Keep a record of your activities before, during, and after cleanup. Take photo or video recording inventory of discarded material.
Step Three: Clean it up!: Start with vacuuming as much loose debris and soil as possible. It is preferable to use a HEPA vacuum, but a simple wet/dry vacuum can work. When using a wet/dry vacuum, attach a hose to the exhaust and vent the exhaust air to the outside. This keeps dust, spores, and other fine particles from being suspended in the air and settling back on clean surfaces.
Clean framing with a pressure washer or low-pressure flushing. Scrub framing with a mild detergent (e.g. dish soap) to remove embedded soils. Wipe all adjacent surfaces with a mild detergent. Rinse by low-pressure flushing or wiping with clean water. Vacuum all remaining moisture using a wet/dry vacuum.
If mold is visible and remains after cleaning, additional scrubbing or multiple rounds of cleaning may be necessary. If significant mold growth is present, or if occupants have immune deficiencies, are elderly, pregnant, or if there are young children present, an IICRC-certified restorer should be contacted.
After all surfaces are clean, wipe surfaces with a sanitizer such as a solution of up to one-fourth cup of bleach to one gallon of water. After 20 minutes, wipe surfaces using clean water. This step helps neutralize remaining or embedded contaminants. For those with chemical sensitivities, perform multiple rounds of cleaning as an alternative to using bleach.
Step Four: Dry it out—quickly!: Mold spores are everywhere, and it is impossible to remove all spores and potential contaminants. All spores need to grow is moisture. To inhibit future mold growth, dry affected areas as quickly as possible, preferably within 24 to 48 hours from the completion of cleaning and sanitizing.
The key is directing warm, dry air across wet surfaces. This directed airflow should be exhausted outside or collected using dehumidification equipment. Take care to not spread contaminants. Properly directing airflow may require putting up barriers or containing the affected areas to prevent the spread of contaminants to unaffected areas.
In a community-wide flood, the availability of power and rental equipment to complete structural drying can be a challenge. If drying cannot be properly initiated, contact an IICRC-certified firm.
Step Five: Keep it dry!: The cardinal rule for preventing mold growth is to keep surfaces dry. Strive to ensure your home stays dry and you will be following industry best practices for preventing mold growth and protecting the health of others in your home. Try to keep indoor humidity below 50 percent using air conditioning or a dehumidifier.
Tip: Use a water-sensing alarm (battery-operated) in moisture-prone areas such as next to the washer, hot water heater, in the basement and other possible wet zones, so you are alerted to the accumulation of excess moisture.
The Healthy Facilities Institute (HFI) strives to provide authoritative information for creating and maintaining clean, healthy indoor environments.
The Healthy House Institute (HHI) provides consumers information to make their homes healthier.
The Institute of Inspection, Cleaning and Restoration Certification (IICRC) is an international, ANSI-accredited standards-development organization that offers certification programs for individuals in 20 plus categories within the inspection, cleaning and restoration industries.
