Can White Foam Board Insulation Be Installed on the Inside of a Wooden Wall?

Identification

• Foam board insulation is used to insulate many areas in residential homes. These rigid panels of insulation reduce thermal resistance and add strength to your home's structure. Foam board insulation sheathing is especially effective in reducing heat transfer through wooden walls. Most foam board insulation is made from polyurethane or polystyrene.

Types

• Beadboard is also known as molded expanded polystyrene foam board, or MEPS. These rigid panels of foam have an R-value of 3.8 to 4.4 per inch of thickness, according to the United States Department of Energy. Polyurethane foam board insulation is also commonly used to insulate interior wooden walls. These foam panels have exceptionally high R-values of 5.6 to 9 per inch of thickness. Both beadboard and polyurethane foam board insulation are available with facings that act as vapor barriers, which is especially important in very cold climates or in hot, humid conditions.

Installation

• How well your foam board insulation works depends largely on proper installation. Therefore, the United States Department of Energy recommends having it installed by a professional contractor. Obtain several written estimates that include the R-value of the insulation used for comparison. Foam board insulation can be installed as a do-it-yourself project for those who have some construction experience. Follow the manufacturer's instructions and adhere to all fire and building codes if you install insulation yourself.

Considerations

• Foam board insulation works best when your home is properly air sealed. Before installation, seal all gaps with caulk to prevent air from moving in and out of your home. Excess moisture can damage your foam board insulation and make it less efficient. If you live in a cold climate or where it is humid much of the year, install an insulation with a vapor barrier. When foam board insulation becomes damp or saturated, mold growth may occur.