Does this vary by product.
R value of canned spray foam insulation.
These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.
But are canned spray foams open or closed cell.
Canned spray foam is widely used to seal between a window frame and it s rough opening and around all sorts of envelope penetrations.
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.
All these have r values ranging from r 3 2 to r 3 8 per inch.
Two part closed cell spray foams have r values ranging from r 5 to r 6 per inch.
All those openings in your home are like tunnels for heat and air.
Traditional insulation such as cellulose or fiberglass is not comparable to spray foam insulation in r value as those insulation methods use r value of heat transfer.
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 your attic to reach r 30 if you live in zones 2 or 3.
Simple question folks.
However there are open cell spray foam insulation products actually offer r 3 7 per inch such as icynene classic and.
And if they re open cell my hunch based on stated r values then are they reliable air barriers if they re less than 3 5 to 5 5 inches thick.
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.
Touch n foam 2 component spray foam expands and touch n foam 2 component spray foam expands and cures quickly to fill cavities gaps cracks expansion joints and other sources of air leakage in a building envelope.
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.
Great stuff gaps and cracks insulating foam sealant is the original gap and crack attacker.
Closed cell spray foam r values.
Closed cell spray foam insulation.
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.
For 6 inches r 15 or r 19 etc.
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 foams are between 5 and 1 lbs per cubic foot and have an r value of 3 0 4 0 per inch of insulation.
Spray foam insulation seals these gaps and prevents air and moisture penetration in wall cavities rim joists attic top plates and more.
For example closed cell spray foam depending on brand can offer an r 6 or r 7 per inch.
Open cell foam insulation values r3 r4.
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.