Polyiso Roof Insulation R Value Per Inch

Dated its r value recommendations for polyisocyanurate insulation used in roof systems.

Polyiso roof insulation r value per inch.

Fm approved subject to the conditions of approval as a roof insulation when installed as shown in the current edition of the factory mutual research approvals guide. Membrane roof systems 2015 nrca had recommended designers use in service r values of 5 0 per inch thickness in predominant. Jm is proud to be a pima member and have its product third party certified under the pima quality mark program. Polyiso has a high r value per inch compared to other insulation products.

Jm revised lttr values. Polyiso still remains the highest r value per inch of any available insulation. It has one of the highest r values per inch of thickness among common insulations. However labeled r value differs from in service r value for many insulations.

Polyiso is unique in that the r value increases with the thickness of the foam so three inches of polyiso has a higher r value per inch than two inches. Let s use the r value of iko s polyiso insulation enerfoil tm as an example. Jm suggests that design professionals use 5 7 r inch as a design specification for its foam products. Membrane roof systems 2011 and the nrca roofing manual.

R value chart for enerfoil tm rigid foam faced insulation conditioned per atsm c1289 test method astm c518 1 2. Polyisocyanurate insulation is a common commercial and residential roof and wall insulation. Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness.