Spray Foam Roof Insulation R Value

During the 1970s in idaho s snake river valley my firm insulated the walls of many new homes with 1 25 inches of spray in place polyurethane foam.

Spray foam roof insulation r value.

4 5 21. Very good air bypass leak sealing properties. As a benchmark one inch of solid wood has an r value of 1. Closed cell spray foam insulation is vapor and air impermeable.

8 3 4 4 8 2 20. 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. Using this value we were putting an r of 1 25 x 9 09 11 36 in the walls.

Insulation level are specified by r value. The r value of closed cell foam is r 6 5 7 per inch. So let s find out what you need and discuss how you can get there effectively but also cost efficiently. Corrosion problems when in contact with steel roofing moisture.

Recommended home insulation r values. The higher the r value the better the thermal performance of the insulation. In regards to closed cell sprayed in foam insulation r value can range between r 4 9 to r 7 1 per inch. All these have r values ranging from r 3 2 to r 3 8 per inch.

R 0 77 30 phenolic foam insulation r values. By expanding 100 times its original size icynene seals cracks and gaps in attics walls ceilings and other spaces where air might escape. The r value for open cell is typically around 3 7 at 1 thick and varies by manufacture. Contractors often use it to insulate under slabs ceilings walls and roofs.

It performs much better than any form of batt for stopping air flow but it is not as complete of an air seal as closed cell spray foam. Innovations such as icynene proseal le allows for an initial pass of five inches 5 to achieve r 35. The table below shows what levels of insulation are cost effective for different climates and. Open cell spray foam typically has an r value of 3 5 per inch and it should be noted that open cell does not form a tight air seal.

R value is a measure of insulation s ability to resist heat traveling through it. Open cell spray foam insulation is air impermeable and is applied with a minimum of 3 5 on average and can be used for attics interior floors walls and soundproofing. 4 8 7 21. Closed cell insulation products such as icynene proseal allow builders and architects the ability to achieve r 21 in a three inch pass.

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. Phenolic foam spray insulation. In 1970 the popular number for the r value of one inch of urethane foam was 9 09 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.