Prevent further damage to your flooded home – and your health

(03/15/16) BATON ROUGE, La. – A flood-damaged home requires special attention to avoid further damage and health hazards from molds, other fungi, algae and bacteria, according to LSU AgCenter housing specialist Claudette Reichel.

“Wetness and high humidity spur their growth within two to three days, so it’s essential to act fast after a flood,” Reichel said. “Mold and other fungi are bad for the house and for the occupants.”

Mold spores are an allergen, and some types of molds produce mycotoxin, she said, and decay-causing fungi grow in wood that stays wet for an extended period, causing it to lose strength.

“In a nutshell, a wet house is soon an unhealthy house and eventually a rotting house,” Reichel said. “To make matters even worse, such secondary damage may be excluded from coverage on your flood and homeowners insurance.”

If your home was flooded, it should be cleaned and dried quickly and thoroughly to prevent mold and future damage by wood rot. Because flood water may be contaminated with sewage or other biological pollutants, you should use a disinfectant, too, Reichel said.

However, areas that are wet because of clean rainwater, for instance from a leaking roof, may not need to be disinfected.

“All wet areas should be allowed to dry thoroughly before being covered or enclosed,” she said.

Although a professional water damage restoration contractor with special drying equipment is the best and safest way to go, many homeowners may not have that option following a flood, Reichel said.

For safety, wear protective clothing on legs, arms, feet and hands while cleaning up debris. “Wear rubber gloves and goggles while handling flood-damaged items,” she said.

Buildings built before 1978 may have lead-based paint, which can create a health hazard if it’s sanded or scraped. Information on lead-based paint is available online at Any contractor hired to do any work that could disturb paint should be certified by the Environmental Protection Agency as a Lead Certified Renovator.

Choose and use disinfectants carefully because they can pose a hazard. “Commercial disinfecting cleaners need to be diluted as directed to be effective,” Reichel said.

Bleach solutions, such as 1/4 to 1/2 cup of liquid chlorine laundry bleach to a gallon of water, are economical, general-purpose disinfectants, but they can damage finishes, colors and metals, and pose hazards to people.

“Never use chlorine bleach in or near an air conditioning system,” she said. And never mix bleach with products containing ammonia or acids, which can produce toxic fumes.

Remove wet carpets, carpet pads and rugs within 24 hours. “You may be able to clean valuable carpets and rugs, but you should always replace carpet pads,” Reichel said. Also remove vinyl, laminate and other impermeable flooring over wood floors immediately after the flood has receded.

Disinfect concrete slabs and clean wood subfloors.

Drying wood floors may take weeks in our humid climate, less if you can dehumidify the space. “A buckled subfloor may flatten out on drying,” Reichel said. “Be patient.”

For wood floors, carefully remove a board every few feet to reduce buckling and leave the spaces open until the flooring is dry.

Check inside exterior walls for wet insulation and remove all of it, even if it means cutting into wallboard, Reichel said. Flush out the insides of the walls.

Make sure wet areas are thoroughly dry before installing new insulation. If possible, use air conditioning and a dehumidifier to speed the drying by drying the indoor air.

Fiberglass, cellulose and other porous insulation should be replaced with new material. “Saturated insulation will hold water, even if the wall looks dry, and eventually will cause wood rot and mold problems,” Reichel said.

You can eliminate the need to replace insulation in the event of a future flood if you use insulating foam board of extruded polystyrene cut to fit or closed cell spray foam filling up to 60 percent of the wall cavity, she said.

Any wet insulation in an attic should be removed and not replaced until everything is dry.

Open doors on closets and cabinets and remove drawers for drying and to let air circulate. "With slow drying, these may be salvageable, depending on the materials,” Reichel said.

Paneled walls may be saved by prying the paneling loose at the bottom. Remove any wet insulation, wash the wall cavity and prop the bottom of the paneling away from the sill until everything is dry.

Remove vinyl wallpaper to allow drywall or paneling to dry, Reichel said. Removing baseboards will help too.

Refinishing interior walls with latex paint – never vinyl wallpaper – allows the walls to continue to dry to the inside. However, a shellac-based sealer may be needed to cover ceiling water stains before painting.

When replacing flood-damaged material, consider using flood-hardy materials that could withstand future flooding and need only cleaning, Reichel said.

“Choose ceramic tile, solid vinyl tile or solid wood flooring with a vapor permeable finish and elevate equipment when feasible,” she said.

If flooded walls have solid wood studs and plywood or board sheathing, consider using closed cell foam spray insulation or rigid foam boards to fill 60 percent of the wall cavity, and finish with paperless drywall, leaving gaps behind the baseboards.

After another flood, you could then remove the baseboards and flush out the wall cavity, avoiding gutting and replacing water-damaged materials.

For more disaster recovery information, click here. A detailed how-to guide, Rebuild Healthy Homes: Guide to Post-disaster Restoration for a Safe and Healthy Homes is published by U.S. Department of Housing and Urban Development and available online or as a mobile app, Reichel said.

For more information about hazard-resistant and high performance housing click here or visit LaHouse Resource Center near the LSU campus in Baton Rouge.

3/15/2016 8:25:43 PM
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