Spray Foam Insulation R Values Per Inch

The closed cell spray foam stops air infiltration and provides about an r 5 per inch.

Spray foam insulation r values per inch.

Comparing fiberglass to foam fiberglass is the less expensive choice for wall insulation and is the spray foam insulation rental industrial spray foam insulation jun 12 2017 focusing on spray foam insulation materials there is a difference. Open cell foam insulation values r3 r4. For example closed cell spray foam depending on brand can offer an r 6 or r 7 per inch. 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.

Products with a higher r value provide greater insulation. Varies widely but filling a 2 4 cavity to r 13 with closed cell spray foam costs about 3 50 to 5 25 per sq. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system. 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. 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 foam r values spray with an r value of 3 5 per inch per inch of thickness. 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.

For example a wall with 3 fiberglass batting r value of 10 8. That means if you used foam it green closed cell which is r 7 per inch it s r value for a 3 5 deep wall. The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. All these have r values ranging from r 3 2 to r 3 8 per inch.

Spray foam insulation vs fiberglass r value is about equal for open cell insulation and about double for closed cell insulation per one inch layer. Closed cell spray foam insulation. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and an inch of blown cellulose in an attic has an r value of 3 2 3 7. 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.

Insulate rim joists and other large areas with this product meant for big jobs. Eco spray foam insulation. 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. 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.

Made with plant based products such as soy eco spray foam is more eco friendly. And roofs closed cell spray foams provide a higher r value per inch than less expensive insulation types like fiberglass cellulose or open cell foam.