Moisture and Pest Management

The right insulation can significantly impact moisture management and is critical to the health, energy performance, sustainability, and overall livability of a raised wood floor home. Particular attention is recommended in coastal and other moisture-rich environments, especially hot, humid climate zones.

When deciding on insulation, consider the minimum R-value required, construction cost, home occupant energy use and related costs, off-gassing of volatile organic compounds, and the insulation’s compatibility with other construction methods and materials used, as well as with both the site-specific and the surrounding environment.

Common thermal barrier-type insulations include options such as fiberglass or cellulose batt, open-cell sprayed cellulose, and closed-cell sprayed foam.

Thermal break insulation, including rigid foam board, is typically installed at the exterior face of the thermal envelope. This type of insulation provides continuous protection, excluding thermal bridging materials, and is often placed behind exterior finish materials or between footings/foundation walls and bearing soils in frost-protected or thermally enhanced foundations.

Radiant barrier-type products, such as foil-faced structural panels, have been proven to enhance home energy performance when sufficient, continuous “air space” is immediately adjacent to the foil surface, but are redundant if insulation eliminates the required void.
Don’t overlook the vapor barrier. Wood and wood fiber-based products must be allowed to “breathe;” otherwise, their service life can be reduced. The improper use of vapor retarders, including insulation products such as closed-cell spray foam which forms a vapor barrier, may damage structural elements where wood products are unintentionally encapsulated.