Polyiso Roof Insulation R Values

Tapered polyiso minimizes the negative effects of ponding water and extends the service life of a roof.

Polyiso roof insulation r values.

Membrane roof systems 2011 and the nrca roofing manual. 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. At one inch thickness enerfoil tm achieves a 6 2 r value or a 1 08 rsi. Jm is proud to be a pima member and have its product third party certified under the pima quality mark program.

Measuring the r value of polyiso roof insulation at the website of pima polyisocyanurate insulation manufacturers association discusses long term thermal resistance lttr the astm standards underlying the r values for polyisocyanurate insulation and provides r values for various thicknesses of polyiso which increases in r value per inch as total thickness of the installation increases. Polyiso still remains the highest r value per inch of any available insulation. 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. Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness.

Jm revised lttr values jm suggests that design professionals use 5 7 r inchas a design specification for its foam products. Membrane roof systems 2015 nrca had recommended designers use in service r values of 5 0 per inch thickness in predominant. Acfoam ii is offered in a variety of thicknesses providing long term thermal resistance lttr values from 5 7 to 26 8. Competitors may require up to 3 1 of insulation to achieve comparable ratings.

But what does that mean and how do researchers determine r value. Carlisle s tapered insulation helps promote rooftop drainage while providing excellent insulating value. Dated its r value recommendations for polyisocyanurate insulation used in roof systems. Polyiso roof insulation is the most widely used product for low slope commercial roofing and provides a high r value that helps meet today s energy code requirements without the added thickness or weight of other products.

More projects select polyiso roof insulation for both new and roof replacement systems than any other insulation product. Polyiso has a high r value per inch compared to other insulation products. Closed cell polyisocyanurate polyiso foam core integrally bonded to non asphaltic fiber reinforced organic felt facers. In the nrca roofing manual.