Polyurethane is the most common type of spray foam insulation used as an alternative to traditional building insulation.
It was originally used by the military back in the 1940’s in war plane construction. It was not until the 1950s that polyurethane began to be used in home insulation and it didn’t become popular until the 1980’s when a special spray foam nozzle was developed that allowed for easy application, given the need for the spray foam to mix only second before being sprayed, expanding and then drying into a hardened plastic.
Polyurethane spray foam insulation can be applied to a variety of surfaces including onto roof tiles, concrete slabs, into wall cavities, and through holes drilled into a cavity of an existing wall. Although more expensive than traditional building insulation, Polyurethane spray foam insulation offers the highest level of energy efficiency and gives added strength, air integrity, moisture resistance and blocks out molds, pollutants, toxins and dust.
Spray foam insulation can be categorized as open cell or closed cell. Open cell spray foam insulation is less expensive and provides an excellent air barrier but it does not provide a barrier against water vapour. Sponge-like in appearance, it is often used on interior walls as a sound barrier.
Closed cell foam insulation is a much more dense, with a smaller, more compact cell structure. It provides a strong barrier against air and moisture and can be used anywhere – inside and out. Closed cell spray foam insulation is also used to improve the stability of homes in hurricane and earthquake zones. This improved stability makes spray foam an excellent insulation for any new home construction.