The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13.
Attic spray foam insulation r value.
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.
However there are open cell spray foam insulation products actually offer r 3 7 per inch such as icynene classic and.
The higher the r value the better the thermal performance of the insulation.
Spray foam insulation is a great product.
Homes insulated with it can be some of the most efficient and comfortable homes built.
Closed cell spray foam r values.
These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.
For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3.
According to industry publication fine home building the r value for open cell spray foam is between r 3 5 r 3 6 per inch.
Open cell spray foams are between 5 and 1 lbs per cubic foot and have an r value of 3 0 4 0 per inch of insulation.
For 6 inches r 15 or r 19 etc.
Focusing on spray foam insulation materials there is a difference between the two main types.
For example closed cell spray foam depending on brand can offer an r 6 or r 7 per inch.
Closed cell spray foam insulation.
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.
R values are additive so you can multiple the number of inches of insulation thickness times the r value to arrive at a total insulation value.
I ve been in plenty of these homes and can tell you that when spray foam is installed properly they outperform 99 of fiberglass batt insulated stick built homes.
R value is a measure of insulation s ability to resist heat traveling through it.
It has a lower r value per inch than closed cell foam and is vapor permeable.
The table below shows what levels of insulation are cost effective for different climates and.
Recommended home insulation r values.