Spray Foam Roof Insulation R Value

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

Spray foam roof insulation r value.

In 1970 the popular number for the r value of one inch of urethane foam was 9 09 per inch. 4 5 21. Contractors often use it to insulate under slabs ceilings walls and roofs. R value is a measure of insulation s ability to resist heat traveling through it.

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. Closed cell insulation products such as icynene proseal allow builders and architects the ability to achieve r 21 in a three inch pass. 8 3 4 4 8 2 20. The higher the r value the better the thermal performance of the insulation.

The r value of closed cell foam is r 6 5 7 per inch. The r value for open cell is typically around 3 7 at 1 thick and varies by manufacture. In regards to closed cell sprayed in foam insulation r value can range between r 4 9 to r 7 1 per inch. As a benchmark one inch of solid wood has an r value of 1.

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. Insulation level are specified by r value. 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.

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. Corrosion problems when in contact with steel roofing moisture. Closed cell spray foam insulation.

All these have r values ranging from r 3 2 to r 3 8 per inch. Open cell spray foam r values. 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. 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. Phenolic foam spray insulation. 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.

Very good air bypass leak sealing properties. 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. Icynene sprayed in foam is an insulation and air seal system that works to help ensure that your home doesn t suffer from air loss while providing an effective r value. Along with knowing the r value of a particular insulation it is also important to calculate the r value of a total system.