News Brief

Mechanical—Not Natural—Drying Is a Must After a Flood

Long-term research confirms that airing it out doesn’t cut the mustard (or the mold) after major moisture damage.

Photos show the test home during (exterior) and after (interior) three weeks of flooding.

Photos: Home Energy Magazine and Tuskegee University
New research reinforces the importance of forced mechanical drying after long-term flooding. Mimicking conditions during and after Hurricane Katrina, researchers from Tuskegee University built, flooded for three weeks, and then dried a home to determine the effects of long-term saturation, natural and mechanical drying, and mold remediation on the building materials.

The results, published in Home Energy magazine, are a follow-up to earlier Tuskegee research on short-term flooding. The earlier findings suggested natural drying is adequate for homes flooded for three days and left sitting for five days, but long-term flooding likely calls for more aggressive action, author and lead researcher Heshmat Aglan, Ph.D., P.E., explains.

The findings provide empirical support for a variety of recommendations for drying and remediation after long-term flooding:

  • In the study, natural drying was not effective at reducing building material saturation after three weeks of flooding and three weeks of sitting.
  • Mold spores decreased after natural drying began, but forced drying made the process much faster, suggesting the latter is a more effective option after long-term flooding.
  • Absorbent furnishings and cabinetry should be removed from the building during drying.
  • Paper-faced building materials should be completely replaced after long-term flooding. According to Aglan, the paper facing on fiberglass batts and drywall both continued to show mold growth two years after drying and remediation of the test home.


Published December 1, 2014

Melton, P. (2014, December 1). Mechanical—Not Natural—Drying Is a Must After a Flood. Retrieved from—not-natural—drying-must-after-flood

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