Spray Foam R Value Chart

Installing more insulation in your home increases the r value and the resistance to heat flow.

Spray foam r value chart. The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. It has a lower r value per inch than closed cell foam and is vapor permeable. Closed cell spray foam insulation is vapor and air impermeable and is applied with a minimum of 2 on average with use on on interior and exterior building applications. 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.

These r values are a sum meaning this should be the total r value once you add up the entire depth 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. The r value for open cell is typically around 3 7 at 1 thick and varies by manufacture. 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.

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 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. A typical 2 4 stud filled with open cell spray foam will have an r value between 10 5 and 14.

As a benchmark one inch of solid wood has an r value of 1. 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 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 insulation.

Closed cell spray foam insulation. 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. Use the following chart to estimate an ideal r value for your insulation project. 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 in your attic to reach r 30 if you live in zones 2 or 3.

The r value of some insulations also depends on temperature aging and moisture accumulation. The r value for closed cell is typically around 6 7 at 1 thick and varies by. For example closed cell spray foam depending on brand can offer an r 6 or r 7 per inch. As always should you have any questions or require any assistance in planning your spray foam insulation job please contact us we are always happy to help.

All these have r values ranging from r 3 2 to r 3 8 per inch.