If your home was flooded, make sure it is rebuilt and insulated properly.

“The desire to get flooded homes rebuilt before winter is understandable, but homeowners need to ensure they rebuild right so they do not create long-term problems,” says Carl Pedersen, energy educator with the North Dakota State University Extension Service.

“Flooded homes will need to have the walls open to allow for proper drying, so this is an opportune time to ensure air sealing and insulating is done correctly before wall cavities are closed back up,” he adds. “Rebuilding and insulating your home properly now can reduce your energy use and save you money in the long term.”

Homeowners also need to make sure contractors are using recommended building techniques. While local builders understand the proper way to build homes to withstand harsh Northern winters, contractors from other areas may not have the same attention to detail.

The North Dakota State Building Code has specific insulation requirements based on international codes. However, many jurisdictions have not adopted the most recent requirements for insulation levels in residential buildings, so the individual homeowner needs to ensure contractors install the proper amounts of insulation to provide long-term energy savings as well as comfort once homes are rebuilt.

North Dakota’s Building Code provides requirements for insulation levels in homes based on a particular area’s climate. The values in the code are based on the R-value of the insulation material, which is a material’s resistance to heat flow. Basically, the higher the R-value, the better the material is at insulating.

The requirements for Northern climates are to insulate attics to an R-49 value, which is roughly 18 to 22 inches of insulation, depending on the material being used.

Exterior walls that are above ground should be insulated to at least an R-19 value. If the home was constructed with 2- by 6-inch wall studs, this R-value can be reached easily because most home improvement and hardware stores carry insulation that will meet the R-19 level in a 6-inch cavity. For older homes that may have been built using studs that are only 4 inches deep, you’ll need to use additional techniques to reach the required level.

“By adding an inch of rigid insulation on the exterior of the home and then insulating the stud cavities, the homeowners should be able to reach an acceptable insulation level,” Pedersen says.

Foundation and basement walls also need to be insulated, but homeowners have to select the insulating material carefully because of the moist conditions found in most basements. For example, fiberglass is not recommended in basements because of the moisture problems.

Basement walls should be insulated to at least an R-10 value. Extruded polystyrene foam insulation typically has an R-value of 5 per inch, so insulating foundation walls with 2 inches of the rigid foam boards would meet the requirements.

Air sealing can be just as important as insulating properly. Air leaking out of a home can carry moisture and heat into walls cavities that are not constructed properly. The leaking air will not only cost the homeowner money in heating expenses but could create hazardous conditions due to mold growth.

The NDSU Extension Service and Northern Lights Chapter of Habitat for Humanity are holding a workshop for homeowners on rebuilding flooded homes from 7 to 9 p.m. Aug. 25 at the Grand International in Minot. The topics covered will include insulating, proper air sealing and dry walling techniques. For more information, contact Pedersen at (701) 231-5833 or your local county Extension office.

NDSU Agriculture Communication - Aug. 22, 2011