Polyiso Roof Insulation R Value Per Inch

Polyiso offers a r 6 5 and the highest r value per inch when compared to other insulation.
Polyiso roof insulation r value per inch. Lttr value published by polyisocyanurate insulation manufacturers for 1 and 1 5 inch thick samples. Conditioned per atsm c1289 test method astm c5181 2. Jm revised lttr values. 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. 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. Membrane roof systems 2015 nrca had recommended designers use in service r values of 5 0 per inch thickness in predominant. R value chart for enerfoil tm rigid foam faced insulation.
Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness. Membrane roof systems 2011 and the nrca roofing manual. Thickness inches r value in i p imperial rsi r value in metric 0 5. Dated its r value recommendations for polyisocyanurate insulation used in roof systems.
As a reasonable estimate of the actual thermal performance of polyisocyanurate insulation over the lifespan of a roof assembly. In the nrca roofing manual. Since 1987 the national roofing contractor s association nrca has recommended designers use r 5 6 in. Polyiso has a high r value per inch compared to other insulation products.
Because it s highly energy efficient with the highest r value ratings per inch the use of iso 95 gl insulation in a firestone roofing system provides a cost effective solution for today s oof design r challenges and is preferred for any and every roofing system. Polyiso still remains the highest r value per inch of any available insulation. Not all industry stakeholders are in agreement with the r 6 in. High density polyisocyanurate foam core.
Firestone iso 95 gl insulation the highest thermal ratings.