Spray foam is an effective product for many insulation projects if you follow the guidelines below. For guidance on Energy Trust installation requirements, refer to the 2015 Weatherization Specifications Manual, sections IN 1.5, AT 2.7 and UN 2.10.

The following types of spray foam can meet the needs of a variety of insulation projects:

• Closed-cell polyurethane foam is one of the most expensive and effective insulation products on the market. It doubles as an air and vapor barrier with an R-Value of R-6 or more per inch. It also has tremendous strength and durability, with installation densities of approximately two to three pounds per cubic foot. Closed-cell polyurethane foam requires an ignition or thermal barrier after installation to comply with International Building Code requirements.
• Open-cell polyurethane foam is commonly referred to as half-pound foam because it is installed at densities of about 0.5 pounds per cubic foot. With an R-Value of approximately R-3.7 per inch, it is available in a high-expansion spray form and a lower-expansion injectable form. It has very little structural strength and does not act as a vapor barrier because it can absorb water and water vapor, increasing the potential for mold growth. This product is less flammable than other forms of spray foam, and still requires an ignition or thermal barrier after installation to comply with International Building Code requirements.
• Air Krete injectable foam is a low-expansion, non-toxic and non-combustible “green” alternative to polyurethane-based foams. It has an R-Value of R-3.9 per inch and is installed at densities of 1 pound per cubic foot. It is pest and mold resistant. This product is made of air, water and magnesium oxychloride cement, and does not require an ignition or thermal barrier because it is non-combustible.
• Tripolymer injectable foam is a non-toxic, biodegradable and low-expansion injectable foam with very low flammability. With an R-Value of R-5.1 per inch, it is installed at approximately 1.2 pounds per cubic foot. Similar to Air Krete, tripolymer injectable foam is injected into cavities through a fill tube and is commonly used to insulate hollow masonry walls.