Spray polyurethane foam insulation, also called spray foam, is an emerging technology that is regularly used in both residential and commercial construction. Spray foam is a two-component system that is spray applied as a liquid and expands in place to provide an insulation and air barrier in a single application. These products are plastic, so there is no food value for mold or mildew and they can assist earning points for sustainable programs due to their energy efficiency benefits and the use of renewable and recycled materials.
In the world of spray foam there are two categories of products: open-cell and closed-cell foam. Open-cell spray foams are also referred to as low-density, because they are typically less than one pound per cubic foot. These materials are semi-rigid, typically use water as the blowing agent, and achieve excellent sound attenuation properties. On the other hand, closed-cell foam includes an array of products used for interior and exterior insulation and roofing applications. This article will discuss a subset of the closed-cell foam market that is referred to as medium-density foam and is primarily used for interior and exterior insulation. These materials are rigid, have low vapor permeance properties and can be exposed to weather during a typical construction timeframe.