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.
Open cell polyurethane foam r value.
The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13.
They contain low conductivity gases in the cells usually one of the hcfc or cfc gases the higher r values r 7 0 to 8 0 are the result of thermal resistance of the gases in the cells.
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.
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.
Open cell spray foam r values.
Polyurethane and polyisocyanurate are both closed cell foams.
Two inches of closed cell foam will provide r12 r14 of insulation.
By expanding 100 times its original size icynene seals cracks and gaps in attics walls ceilings and other spaces where air might escape.
Icynene sprayed in foam is an insulation and air seal system that works to help ensure that your home doesn t suffer from air loss while providing an effective r value.
Just like for open cell foam r values are additive.
Closed cell spray foams are between 2 and 4 lbs.