Draft SPF Builders Handbook

SPFA is offering a compendium of sprayfoam technical, safety, contractor certification, and installation information of specific interest to homebuilders. Download the draft document.

Why use spray foam insulation?

Spray foam is one of the most advanced insulation and building envelope systems on the market today. Spray foam insulations combine high R-value and air infiltration control, the two major factors in achieving energy efficiency in homes. Most other insulations do very little to control air infiltration which can account for as much as 40% of a home's energy losses. And air leaks don't only allow conditioned air to escape homes, they also can significantly reduce the R-value of traditional insulations due to an effect called wind washing. Research by ORNL shows that an R-19 batt "commonly" installed only performs at an R-13.7 level. Spray foams resist the heat scavenging effects of air movement much better than more traditional fibrous insulations helping to ensure that the insulation will perform much closer to its listed R-values. This provides much more value to your customers for the same listed R-value because it:

A more consistent air and thermal barrier can also potentially reduce your liability by reducing the likelihood of condensation which can lead to premature deterioration of the home exterior and mold growth.

There are two types of spray polyurethane foam insulations commonly used in residential insulation applications. The first is closed cell foam which is a nominal 2 pounds per cubic foot density. It offers greater than 90% closed cells that are normally filled with inert gases that insulate better than air. The second are referred to as open cell foams and are a nominal 0.5 pound per cubic foot density. In order to drop the density, the cells have to be opened, or less closed cells than a higher density spray polyurethane foam. Both products offer insulation and air barrier characteristics. The physical properties of each should be compared to select the best one for your particular application. Because of their physical differences, some applications may be better than others for each particular product.