Spray Foam R Value Per Inch

Spray foam insulation is the new ish kid on the closed cell foam generally provides the most r value per inch of any widely available option making projects like reclaiming an attic into there must be a better way than pricey spray foam insulation to make a home more energy efficient.

Spray foam r value per inch.

Closed cell spray foam insulation. Jun 12 2017 in regards to closed cell sprayed in foam insulation r value can range between r 4 9 to r 7 1 per inch. Closed cell spray foam provides a higher r value per inch 6 5 than less expensive insulation types like cellulose and fiberglass 3 5 to 3 7. A typical 2 4 stud filled with open cell spray foam will have an 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. The r value of closed cell foam is r 6 5 7 per inch. 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. For example blown fiberglass typically has an r value of only r 2 to r 3 per inch depending on compression density and moisture.

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. Most spray polyurethane foam is called two component foam. All these have r values ranging from r 3 2 to r 3 8 per inch. 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. The r value of. With foamed in place insulation it is relatively easy though not inexpensive to fill wall and ceiling cavities completely. 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.

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. For example closed cell spray foam depending on brand can offer an r 6 or r 7 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. 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.

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. Gear obsessed editors choose every product we review. 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 insulation products such fiberglass batt insulation standard fiberglass insulation batts or blankets provide an r value of 2 2 to 3 8 per inch of thickness.