Spray In Foam Insulation R Value

By expanding 100 times its original size icynene seals cracks and gaps in attics walls ceilings and other spaces where air might escape.

Spray in foam insulation r value.

For 6 inches r 15 or r 19 etc. The r value of spray foam insulation is approximately 6 per inch so those using spray foam as their insulator will need about 6 3 inches of thickness to reach r 38. Open cell foam insulation values r3 r4. However there are open cell spray foam insulation products actually offer r 3 7 per inch such as icynene classic and.

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. Focusing on spray foam insulation materials there is a difference between the two main types. 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. The r value of fiberglass insulation is approximately 2 2 per inch so much thicker fiberglass insulation is required to achieve the same r value of 38.

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. Rigid foam boards trap air or another gas to resist conductive heat flow. Bulky materials resist conductive and to a lesser degree convective heat flow in a building cavity. 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.

The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. 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. Closed cell spray foam insulation. 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.

Insulation materials run the gamut from bulky fiber materials such as fiberglass rock and slag wool cellulose and natural fibers to rigid foam boards to sleek foils. All these have r values ranging from r 3 2 to r 3 8 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 r values.

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.