Open Cell vs. Closed Cell Spray Foam
Open cell spray foam is a softer ½ lb density material that is used for interior applications only. Open cell spray foam acts as both an insulation and air-barrier, providing maximum comfort and superior sound control. Because it is water blown, open cell foam is non-toxic and environmentally friendly. Open cell spray foam expands approximately 100 times its volume with less density and can provide more insulation at less cost.
Closed cell spray foam is a rigid material with a 2lb density. Closed cell spray foam can be used to insulate and waterproof the exterior of building. Closed cell spray foam is also used to insulate and waterproof foundations and roofs. The closed cells also contain an environmentally friendly gas that is less dense than air, providing a higher R-value than the open cell spray foam and the highest R-value per inch of any insulation. Closed cell spray foam also provides both insulation and an air barrier. When sprayed at 2 inches or more, closed cell spray foam also provides a built in vapor barrier, which is why it the product of choice for freezers and coolers.
Both open and closed cell spray foams have a class 1 fire rating.