Dry Water-soaked Building Materials Quickly

Provided by NDSU Extension Service

Water-soaked building materials and carpet need to be dried quickly to prevent mold growth, says Ken Hellevang, a North Dakota State University Extension Service agricultural engineer.

A number of North Dakotans are faced with cleaning up after recent heavy rains flooded their homes.

Carpet needs to be dried within a couple of days, Hellevang says. The best way to do that is to remove or lift the carpet and get the air moving on both sides of it.

Walls must be opened and ventilated. Walls can remain wet for days if not opened, which will lead to mold growth. Water can soak upward a couple of feet in drywall and other building materials.

Wood submerged in water will absorb a large amount of water. Drying the wood adequately can take days or weeks. The drying time depends on the wood's moisture content and the drying conditions. Also, the wood needs to be exposed so it can dry. "Ventilation usually is the best way to dry things out," Hellevang says. "It can remove several gallons of water per day."

Here are some ways to ventilate a home:

• Provide an entrance and exhaust opening to create cross-ventilation through the house.

• Place a fan, facing outward, in a window or door. Seal the rest of the opening with cardboard, plywood or blankets so the fan can create a vacuum.

• Use fans to circulate air over wet surfaces.

• Face fans into corners or other confined spaces. Hellevang says heat also is an important part of drying out a home because it increases air's moisture-holding ability.

Homeowners should use their furnace or large heaters to warm the air. Open windows and ventilate the home to get rid of the moist air and bring in dry, outdoor air.

Dehumidifiers can help dry out a house if the outside air is humid. Dehumidifiers work most efficiently at warm temperatures. For example, most home dehumidifiers will remove 1 to 2 pints of water from the air per hour at a temperature of 80 degrees and relative humidity of 60 percent.

A wood moisture meter can determine if wood is dry enough for homeowners to start rebuilding. Wood should have a moisture content of less than 15 percent before anyone replaces drywall, paneling or other coverings.

"Rebuilding too quickly can cause continuing problems, such as mold growth, insect infestations and deterioration of the wood and wall coverings," Hellevang says.

Homeowners doing their own repairs may be able to borrow or rent a meter from a hardware store or lumberyard. Some NDSU Extension Service county offices have meters available for checkout. Homeowners who hire a contractor to make repairs should make sure the contractor uses a meter to verify that the wood is dry.