Spray Foam Insulation R Value Chart

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.

Spray foam insulation r value chart.

Closed cell spray foam insulation. 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. 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. 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.

The higher the r value the better the thermal performance of the insulation. 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. Recommended home insulation r values. The r value is r 3 5 to r 3 6 per inch so filling a 2 4 cavity yields about an r 13.

The table below shows what levels of insulation are cost effective for different climates and. 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. The overall r value of a wall or ceiling will be somewhat different from the r value of the insulation itself because heat flows more readily through studs joists and other building materials in a phenomenon known as thermal bridging. For example insulation that is compressed will not provide its full rated r value.

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. Insulation level are specified by r value. Closed cell spray foam r values. For example closed cell spray foam depending on brand can offer an r 6 or r 7 per inch.

The common denominator among varieties of insulation is the r value. 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. All these have r values ranging from r 3 2 to r 3 8 per inch. A higher r value prevents more heat from escaping through the insulation.

Homes generally try and reach an r value of 38 with their insulation. In comparison an inch of blown fiberglass insulation has an r value of 3 1 3 4 and. These r values are a sum meaning this should be the total r value once you add up the entire depth of insulation. R value is a measurement of thermal resistance and measures the ability of heat to transfer from one side of an object to another.

Use the following chart to estimate an ideal r value for your insulation project. 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. As a benchmark one inch of solid wood has an r value of 1.