1 Inch Spray Foam R Value

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.

1 inch spray foam r value.

For 6 inches r 15 or r 19 etc. 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. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.

Walls below grade and above grade. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. 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. 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.

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 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. 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.

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. Why spray foam insulation is so effective in meeting code requirements is that it has a higher r value per inch of product used. 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.

I m building at 11 000 feet in colorado. The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13. What really matters is the r. 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.

As a benchmark one inch of solid wood has an r value of 1. All these have r values ranging from r 3 2 to r 3 8 per inch. A 3 5 inch deep fiberglass rockwool or recycled denim batt for a typical 2 4 wall may say it provides r 11 or r 13 depending on fiber density. Closed cell spray foam insulation.

2 6 construction and have the building weather tight but framing exposed inside.