Open-cell foam has a density of .5 lb per ft, one-quarter of the density of closed-cell insulation. It also has an approximate R-value of 3.8 per inch.
Closed-cell insulation has a density of 2 lbs per ft. Because of its density, closed-cell spray foam insulation acts as an air barrier and as a vapor barrier when installed at a depth of 1.5″ or more.
Both open and closed-cell spray foam insulation is more expensive than other insulation types, such as fiberglass or cellulose.
Spray foam insulation is a very effective type of insulation that you can use for nearly any insulation application. It is a mix of chemicals that, when installed, creates incredibly stable and efficient insulation.