Polyiso Roof Insulation R Value Per Inch

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

Polyiso roof insulation r value per inch.

Jm revised lttr values. Polyiso has a high r value per inch compared to other insulation products. 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. 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.

Benefits of energyguard polyiso roof insulation include. Membrane roof systems 2011 and the nrca roofing manual. Jm suggests that design professionals use 5 7 r inch as a design specification for its foam products. However labeled r value differs from in service r value for many insulations.

It has one of the highest r values per inch of thickness among common insulations. In the nrca roofing manual. Dated its r value recommendations for polyisocyanurate insulation used in roof systems. Building science corporation bsc and others have been examining this difference.

Let s use the r value of iko s polyiso insulation enerfoil tm as an example. 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.