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Be Safe When Cleaning Up Storm-Damaged Homes, Businesses

Wall voids and mold
Wall voids can create a good environment for mold growth.

Nebraskans left with storm-damaged or flooded homes and businesses need to be cautious cleaning up the mess, a University of Nebraska-Lincoln specialist said.

Areas of the state have experienced flooding in the last few days including along the Missouri River, among other waterways.

Although it's important to clean up flood damage as soon as possible, several safety issues are key, said Shirley Niemeyer, housing and environment specialist in the university's Institute of Agriculture and Natural Resources.

"It's important to use great caution when assessing and working on damaged structures," Niemeyer said. It's also important for home and business owners to contact their insurance companies to determine the extent of coverage and what records, photos or examples are needed.

"Electrical safety is most important in floods," Niemeyer said. "Watch for electrical shorts and live wires. Also, make sure electrical service is disconnected and any outside gas lines are turned off before attempting to do any work in the house."

When it is safe to enter, an electrician should check wiring and appliances for safety before using electricity.

"Equipment and wiring that appears to be safe soon after flooding may fail prematurely and cause a fire or shock hazard," she said. "Replacement often is the best option."

It's also important to clean up household items to prevent mold and odors after water damage, she said.

When cleaning the home, wear protective clothing, hard sole shoes, rubber gloves and an N-95 or a HEPA air filter mask for extra protection against contamination and particles. Also, be sure exposed skin is washed frequently.

It's important to check the siding and roof for damage to keep further moisture out of the house, Niemeyer said.

"There are places that we don't think about where water may have gotten," Niemeyer said. "Crawl spaces, wall cavities and floor joist areas may need to be dried out, especially if there was extensive water damage."

Mold can start growing in 24 to 48 hours, especially next to anything cellulosic, such as paper or wood. To minimize mold and mildew, run a central air conditioner, dehumidifier or fans to accelerate the drying process when electricity is restored and after ensuring the electrical system in our home is safe to use. Make sure the electrical system is protected with ground fault circuit interrupters at the outlets, Niemeyer said.

Water-damaged furniture and household linens need immediate attention to prevent mold, mildew and odors. To begin the cleaning process, air dry all items outside in direct sun, if possible. Materials that could warp or fade should be dried in the shade.

As for materials such as floor coverings and furnishings, it's generally recommended to discard fibrous or porous materials, such as carpets, soft furniture, ceiling tile, and some insulations, as they are hard to completely clean. Hard, non-porous surfaces usually can be cleaned, Niemeyer said.

Success with cleaning carpets and rugs also depends on the extent and type of water damage.

"Clean water, including regular plumbing leaks or rain water through an open window, may be easier to deal with, while carpets and pads contaminated with sewage, flood water or runoff water should be discarded," Niemeyer said.

Carpets soaked with clean rainwater in a small area may be saved, she said. They should be steam-cleaned by a professional carpet cleaner skilled in flood-damaged carpets.

"If you must attempt to salvage carpet contaminated with clean rainwater yourself, discard the pad," she said. "Do not replace carpet and new padding until the flooring and floor joists are thoroughly dry."

To aid in drying, remove surface and subfloors and open up the floor joist area, Niemeyer said. Drying out subflooring, joists and wall cavities can take up to weeks or months. Moisture meters can help determine the moisture content of wood and other materials and to make decisions about when to replace wallboard (drywall) and flooring.

"Wall cavities often are overlooked and not thoroughly dried out, creating a good environment for mold growth," she said.

Moldings, baseboards, drywall and insulation also should be removed well above the apparent water line. Drywall and fibrous or porous insulation should be thrown away. In addition, moisture can seep into other materials. Allow the cavity to thoroughly dry several weeks to months before replacing any type of drywall or wall covering.

"This is critical for preventing mold growth," Niemeyer said. "Keep humidity levels between 30 % to 50 % RH."

"Keep a vigilant eye out for any signs of odors, moisture or mold growth and run a dehumidifier to control moisture levels," Niemeyer said.

moisture meter
Moisture meters can help determine the moisture content of wood and other materials.
Shirley Niemeyer
Dr. Shirley Niemeyer
Emeritus Extension Specialist - Textiles
Dr. Shirley Niemeyer retired on June 30, 2011 after 41 years of service to the University of Nebraska and the citizens of the state and the nation. A passionate and dedicated Extension Specialist, Dr. Niemeyer's research and work on housing issues and the environment provided opportunities for individuals and families across the state of Nebraska and beyond its borders to make informed decisions about their housing and the safety, decency and affordability of their physical and social environment. During the last several years Dr. Niemeyer has focused much of her efforts on the development of the Home Energy Community of Practice, working with other Extension specialists around the US to bring extensive energy conservation information to a broad audience.