Hidden mold on underside of sub-floor after a flood

Hidden mold on underside of sub-floor after a flood

The above link provides some good information on the hazards that are inherent to flooded buildings. Good information in the clip includes:
• Chemicals, such as pesticides, gasoline, hydrocarbons, rotted food, and other harmful agents can be transported indoors with flood waters.

• Animal fecal material, carcasses and pathogens are inherent to flood waters.

• Fungi (mold) grow indoors on drywall, wood, and other cellulose contents.

• Mold that grows indoors can make people sick.

• Moldy drywall must be discarded.

The overall message that water damage to buildings is unhealthy was very clear in the news clip. However, due to the shortness of the clip, information was limited. The public should be aware of that many hazards exist after floods. As reported by the World Health Organization (Dampness and Mould, 2009), other harmful agents in water damaged buildings include bacteria, endotoxins and exotoxins from bacteria, mycotoxins from mold, chemicals released from wet building materials, insects, and other contaminants that can be transported indoors with surface and ground water.

The media clip does fall short relative to its discussion about clean-up. The recommendations from the interviewed mold expert do not emphasize that flood clean-up is not a do-it-yourself project. Although the reporter and expert donned protective gear prior to entering a flooded house, the importance of hazard training and medical clearance for using personal protective equipment is not addressed. This could turn into a situation where a little knowledge could be dangerous.

The issue of restoring wood after a flood was misrepresented in the clip. The expert suggested that unless wood was rotted, abrasive cleaning would effectively restore mold contaminated wood after a flood. This is information is not correct. Wood that has been in contact with the flood water is contaminated with the same chemical and biological agents as the drywall that the expert states must be removed. Abrasively cleaning of wood will only address the outer accessible surfaces. Wood has six sides. Ignoring the surfaces that cannot be accessed for cleaning (interface between bottom plates and flooring, stacked studs, etc.) are typically the most contaminated because they remain wet for the longest periods.

The surfaces with trapped contaminants can cause exposure hazards long after restoration and re-build are complete. Contaminants that remain on wood in floor, ceiling, and wall cavities can be liberated with pressure differentials, physical disturbances, and normal living activities. Since people can react to dead mold and other contaminants that remain after a flood, failure to address the “hidden” surfaces could be quite dangerous, especially to people to young children, elderly people, asthmatics, or those that are immune-compromised. Appropriate remediation scopes for damages from catastrophic water losses, such as those caused by Hurricane Sandy, are paramount to preventing future indoor air quality problems.

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