Polyiso Roof Insulation R Value Per Inch

Jm revised lttr values.

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. As a reasonable estimate of the actual thermal performance of polyisocyanurate insulation over the lifespan of a roof assembly. Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness. 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. High density polyisocyanurate foam core. 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. Lttr value published by polyisocyanurate insulation manufacturers for 1 and 1 5 inch thick samples.

Jm suggests that design professionals use 5 7 r inch as a design specification for its foam products. Polyiso has a high r value per inch compared to other insulation products. Tapered polyiso minimizes the negative effects of ponding water and extends the service life of a roof. Firestone iso 95 gl insulation the highest thermal ratings.

Polyiso still remains the highest r value per inch of any available insulation. Jm is proud to be a pima member and have its product third party certified under the pima quality mark program. Conditioned per atsm c1289 test method astm c5181 2. Thickness inches r value in i p imperial rsi r value in metric 0 5.

Not all industry stakeholders are in agreement with the r 6 in. R value chart for enerfoil tm rigid foam faced insulation. Since 1987 the national roofing contractor s association nrca has recommended designers use r 5 6 in. Dated its r value recommendations for polyisocyanurate insulation used in roof systems.

In the nrca roofing manual. Closed cell polyisocyanurate foam technology provides additional insulation value r value of 2 5 with lightweight and low water absorption characteristics. Membrane roof systems 2011 and the nrca roofing manual.