Maryland Green Building Network
    May 6, 2003
    Chesapeake Bay Program Office
    Annapolis, MD
Introductions and Announcements

Sean McGuire, Green Building Network Coordinator, welcomed attendees to the meeting and then reviewed some of the items listed in the previous GBN announcements and alerts.

Mold and Mildew in Buildings – Kevin Powell, NAHB Research Center

Kevin began with a brief introduction to the NAHB Research Center, a non-profit subsidiary of the NAHB. Actually, less than 10% of the Center’s total income comes from NAHB. Instead, the Center receives their income from private companies and industries to test products, provide building science, and conduct market research.

While the media, and some in the legal profession, may overstate the current condition, mold and mildew is in fact a serious problem. Mold is a top concern for homeowners, builders, contractors, realtors, lenders, and others in the development community. In fact, insurance providers are not providing mold coverage and insurance rates are up.

What is mold? Mold is actually nature’s recyclers and naturally lives in many forms. There are more than 100,000 species of mold, and fungi make up about 25% of the earth’s biomass. The risk to people from mold includes those with weakened immune systems, respiratory conditions, the elderly, and infants. The conditions for mold are three-fold: moderate temperature (40-80 degrees), moisture, and an organic source of food. The challenge is that people also like to live in places and buildings that utilize all of these conditions. But the issue that is most easily attacked is moisture. So to address mold, we must address moisture. Some of the ways moisture gets into a building or home is capillary action, vapor pressure, condensation, HVAC condensate, and water intrusion.

Kevin then described some troubleshooting tips. Basically, we need to stop the moisture, but easier said than done. The first step is to aggressively investigate moisture and how moisture is getting into the structure; whether it is water, vapor, or ice. One critical point is to look to the driving force on how exactly the water is getting in or indirectly through a moisture pathway. Kevin demonstrated a detailed tool that analyzes humidity, specifically in bathrooms and kitchens.

Regarding remediation, the best tools available are from EPA and their documentation. Kevin provided copies for both commercial and residential contacts and website information. The basics are: identify the moisture source, stop the moisture source, clean up the mold, replace damaged materials, and protect the health of occupants and workers. Kevin then demonstrated some of the clean-up methods and techniques.

While there is not much research on remediation and mold in structures, the Research Center is currently conducting some studies. The causal factors from mold are from leaks and flooding. This resulted in older homes having more incidents of mold. More than 80% of all mold, not surprisingly, occurs in the kitchen and bathrooms. The Center then looked at case studies to start explaining the mold issue. Some of the areas identified were gypsum, wet attics, and crawlspaces. Kevin then went through a few examples of where mold occurs in the home. Of particular note, ventilating crawlspace is NOT recommended, as condensation occurs in the summer. As in Maryland, codes are not necessarily the answer, as different climates require different approaches.

While there are several treatments for mold, including bleach and borate mold inhibitors, Kevin stated it is a somewhat dangerous approach. The problem is still there and will continue to repeat. Also, some of the chemicals that fix mold are in fact worse than mold, including dursban that was recently identified as a carcinogenic.

To properly address mold, the Center has a ToolBase Hotline: 800-898-2842. Between 15-20% of all calls relate to mold. The ToolBase is also available online at www.toolbase.org. For additional questions or materials, please contact Kevin Powell at 301-430-6287 or kpowell@hagbrc.org. The NAHB Research Center can be contacted by going online to www.nahbrc.org.

Attendees

Return to Green Building Network
Environmental Design Program
DNR Online

Last updated on July 9, 2003