Spray Foam Insulation R Value 2x4

In a 2x4 wall you can use spray foam but it has to be closed cell not open cell.

Spray foam insulation r value 2x4.

Insulation is rated in two ways r value and u value. Closed cell foam is r 7 25 per inch. How to achieve r 21 in a 2x4 wall. 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.

Our open cell foam product has an r value of 3 5 per inch and in most applications a house constructed with 2x4 studs will have 3 5 inches of open cell foam thus resulting in a total r value of 12. Closed cell s obvious advantages compensate for its slightly higher price tag of 15 to 30 for the same thickness. The r value is a calculation which measures the flow of heat through an insulation product or its. Foam it green sprays on fast creating a seamless air and moisture barrier.

Ultimate spray foam insulation has a few different foam products of different densities. And with an r 7 per inch you get to r 21 in 3 inches of foam. But that carries it s own added cost. Code is all about sealing and insulating now.

Open cell spray foam typically has an r value of 3 5 per inch and it should be noted that open cell does not form a tight air seal. They sport an r value of 6 0 8 0 per inch of insulation about double their open cell foam counterparts. Just like for open cell foam r values are additive. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation.

Closed cell spray foam aka two pound foam is denser than open cell at about 2 pounds per cubic foot. Two inches of closed cell foam will provide r12 r14 of insulation. Closed cell spray foams are between 2 and 4 lbs. Its r value is roughly 6 5 per inch.

The installed insulation r value depends somewhat on the system manufacturer but generally speaking high density foam 2 0 pcf ranges between r 5 5 and r 6 5 per inch for the aged r value and low density foam 0 5pcf has an r value of approximately r 3 6 inch. To meet r 20 requirement if that is what code says in your location. 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.