R value is a measurement signifying a material's resistance to heat transfer. A material with a high R Value has a high resistance to heat transfer. R value of a Dura-Foam roof is measured by using the conservative factor of R 6.25 per inch of polyurethane foam. At this rate, a foam roof having a thickness of 1.5" adds an R 9.4 to the roof structure. The actual R value of our polyurethane foam is higher than 6.25, but we use this number to comply with standard building practices accepted by the International Code Council (ICC).

Knowing of how R values are calculated helps to understand why polyurethane foam insulates more effectively than fiberglass and other types of insulation. The test for R Value takes place in an environment with zero humidity and zero air infiltration. In the real world, fiberglass and other types of insulation absorb moisture due to varying humidity levels and they also allow air infiltration. On the other hand, our Spray Polyurethane Foam always has zero humidity and zero air infiltration because it is is closed cell and seamless. Inch for inch, polyurethane foam is has a higher R value and works more effectively than any other type of building insulation. For this reason, a Dura-Foam roof with as little as 1" of foam will completely transform the comfort and efficiency level of a building.