Extension Communications
3614 Administrative Services Building
Ames, Iowa 50011-3614
(515) 294-9915
7/12/00
Contacts:
Tom Greiner, Extension Agricultural and Biosystems
Engineering, (515) 294-6360, tgreiner@iastate.edu
Laura Sternweis, Extension Communication Systems, (515)
294-0775, lsternwe@iastate.edu
Replace Flood-Damaged Drywall and Insulation
AMES, Iowa -- Drywall and insulation damaged by floodwater or sewage backup can pose possible health risks and should be replaced, according to Thomas Greiner, an Iowa State University Extension agricultural engineer.
"All drywall and insulation wetted by floodwater must be thrown out to reduce the risk of microbial growth and possible health risks to occupants," Greiner said.
Even when the drywall, sometimes called wallboard, has dried, mud and contaminants are trapped inside. Insulation typically takes a long time to dry, and when wet it provides the perfect fungi growing place. If not dried within 24 hours, drywall and insulation present a permanent health hazard.
Greiner said although it may be possible to dry out small areas of drywall and insulation damaged by rainwater leaks, it is nearly impossible to dry the drywall and insulation damaged by a flood.
"Even 'clean' floodwater will contain microbes and pose a risk," Greiner said. "There is no satisfactory method to clean and dry drywall and insulation in place. Removing the drywall and insulation assures that the wall cavity can be thoroughly cleaned and dried and that fungi growth can be stopped."
Drywall acts like a sponge and absorbs water past the flood line. "At a minimum, the drywall should be removed to 12 inches above the highest water level, or 12 inches above any wet or damp material," Greiner said.
Drywall that has been soaked four or more feet above the floor should be completely removed and replaced. If the damaged area is less than four feet above the floor, the lower four feet of drywall should be removed and replaced with 4 ft. x 8 ft. sheets of wallboard placed lengthwise. All wet insulation should be replaced.
"Removing and replacing the drywall and insulation is usually less expensive and provides more assurance that health problems to occupants will not occur," Greiner said.
For more information about flood cleanup, contact your local Iowa State University Extension county office.
Extension programs are available to all without regard to race, color, national origin, religion, sex, age, or disability.