Open Cell Polyurethane Foam R Value

Polyurethane and polyisocyanurate are both closed cell foams.

Open cell polyurethane foam r value. Open cell spray foam r values. Just like for open cell foam r values are additive. It performs much better than any form of batt for stopping air flow but it is not as complete of an air seal as closed cell spray foam. By expanding 100 times its original size icynene seals cracks and gaps in attics walls ceilings and other spaces where air might escape.

The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. Open cell spray foam has an r value of about r 3 7 per inch while closed cell spray foam has an r value that may be as high as r 6 5 per inch. Two inches of closed cell foam will provide r12 r14 of insulation. Open cell spray foam typically has an r value of 3 5 per inch and it should be noted that open cell does not form a tight air seal.

If you want to install spray foam in a stud wall and price is no object then it would seem to make sense to specify closed cell spray foam right. Closed cell spray foam insulation closed cell spray foam has a far better r value per inch than other less effective insulations like cellulose fiberglass or even open cell foam. They sport an r value of 6 0 8 0 per inch of insulation about double their open cell foam counterparts.