The table below shows what levels of insulation are cost effective for different climates and.
Spray foam roof insulation r value.
Closed cell spray foam r values.
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 m not going to dive into the energy code here but these numbers apply to many climate zones the latter being allowed under the ua tradeoffs rule.
The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13.
4 8 7 21.
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.
It has a lower r value per inch than closed cell foam and is vapor permeable.
Recommended home insulation r values.
R 0 77 30 phenolic foam insulation r values.
For 6 inches r 15 or r 19 etc.
Open cell spray foam insulation is air impermeable and is applied with a minimum of 3 5 on average and can be used for attics interior floors walls and soundproofing.
Since closed cell foam has a higher r value per inch installers generally spray 2 in walls and 3 in rooflines to meet the energy code requirements of r 13 and r 19 respectively.
A typical 2 4 stud filled with open cell spray foam will have an r value.
Corrosion problems when in contact with steel roofing moisture.
Focusing on spray foam insulation materials there is a difference between the two main types.
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.
These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.
Very good air bypass leak sealing properties.
Phenolic foam spray insulation.
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.
R value is a measure of insulation s ability to resist heat traveling through it.
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.
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.
4 5 21.
8 3 4 4 8 2 20.
Closed cell spray foam insulation.
For example closed cell spray foam depending on brand can offer an r 6 or r 7 per inch.
Having an r value in the neighborhood of r 7 per inch and the ability for some products to be applied 5 inches at once high r value applications are easily achieved.
Insulation level are specified by r value.