Closed Cell Insulation Spray

In the 1970's and 1980's there was a boom for spray foam insulation of both new and old homes. This insulation was made from a urea formaldehyde foam which was later deemed as a possible carcinogenic agent by the Environmental Protection Agency. In the interim both fiberglass batt and blown-in cellulose insulation became the standard.

Foam is now back in a big way but based on urethane. Open-cell foam is soft and used as the liner of packing delicate instruments. The cells are broken and air-filled but this makes the foam structure weak. Open cell does break down over time and readily accepts water.

Closed cell, on the other hand, dries hard with enclosed air cells for a better insulating quality. It will not break down and is water proof. This foam is applied between the studs of new homes and them it expands. The excess is scraped off an then drywall is attached for a sealed unit unlike fiberglass which can have air channels.

The R-value is also twice that of fiberglass batts.