Spray In Foam Insulation R Value

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.

Spray in foam insulation r value.

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. 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. Closed cell spray foam r values.

Icynene sprayed in foam is an insulation and air seal system that works to help ensure that your home doesn t suffer from air loss while providing an effective r value. 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. Rigid foam boards trap air or another gas to resist conductive heat flow. 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.

Bulky materials resist conductive and to a lesser degree convective heat flow in a building cavity. Closed cell spray foam insulation. The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. 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.

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. 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. 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. 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.

However there are open cell spray foam insulation products actually offer r 3 7 per inch such as icynene classic and. For example closed cell spray foam depending on brand can offer an r 6 or r 7 per inch. For 6 inches r 15 or r 19 etc. Open cell foam insulation values r3 r4.

Focusing on spray foam insulation materials there is a difference between the two main types.