Polyiso Roof Insulation R Value Per Inch

In the nrca roofing manual.

Polyiso roof insulation r value per inch.

Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness. However labeled r value differs from in service r value for many insulations. Let s use the r value of iko s polyiso insulation enerfoil tm as an example. Benefits of energyguard polyiso roof insulation include.

Polyisocyanurate insulation is a common commercial and residential roof and wall insulation. R value chart for enerfoil tm rigid foam faced insulation conditioned per atsm c1289 test method astm c518 1 2. Jm suggests that design professionals use 5 7 r inch as a design specification for its foam products. 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.

Jm revised lttr values. Building science corporation bsc and others have been examining this difference. 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. Polyiso has a high r value per inch compared to other insulation products.

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. Membrane roof systems 2015 nrca had recommended designers use in service r values of 5 0 per inch thickness in predominant.