We are pleased to announce the availability of an updated Foam-Control Long-Term Thermal Resistance (LTTR) brochure providing R-value test data on commercially available Polyiso and XPS insulations. The brochure was previously available with R-value data up to an age of 6 months. Now R-value data is available up to an age of 12 months. And, the R-values of the Polyiso and XPS continue to decline.

R-value data was obtained by tests conducted at an ISO 17025 accredited laboratory using ASTM C518, “Standard Test Method for Steady-State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus”. Three 2” thick Polyiso and two 2” thick XPS commercially available insulations were obtained from major industry suppliers. The insulations were tested immediately upon receipt and at regular intervals thereafter for 1 year. R-value data was obtained at mean temperatures of 75 F and 40 F.

The R-value data obtained raises questions on the performance of Polyiso and XPS as they age and when used in cold climates.