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. 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.
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. All wet insulation should be replaced. 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.