Just like for open cell foam r values are additive.
Closed cell spray insulation r value per inch.
That means if you used foam it green closed cell which is r 7 per inch it s r value for a 3 5 deep wall cavity would be r 24 5.
Installing quality insulation is the best thing you can do to improve the energy e closed cell foam r values spray with an r value of 3 5 per inch per inch of thickness.
Spray polyurethane foam spf is better than any other type of insulation at reducing air leakage.
For example closed cell spray foam depending on brand can offer an r 6 or r 7 per inch.
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.
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.
Why spray foam insulation is so effective in meeting code requirements is that it has a higher r value per inch of product used than batts.
Two inches of closed cell foam will provide r12 r14 of insulation.
The r value of closed cell foam is r 6 5 7 per inch.
They sport an r value of 6 0 8 0 per inch of insulation about double their open cell foam counterparts.
Closed cell spray foams are between 2 and 4 lbs.
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.
All these have r values ranging from r 3 2 to r 3 8 per inch.
With foamed in place insulation it is relatively easy though not inexpensive to fill wall and ceiling cavities completely.