Polyiso Roof Insulation Thickness

Other materials may only have a fifty percent increase in r value when their thickness is.

Polyiso roof insulation thickness. Designers specify polyisocyanurate insulation be installed in multiple layers with a 1 inch minimum and 2 inch maximum thickness per layer. 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. Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness. So you need to know an insulation product s thickness as well as its r value in order to compare it to another product.

Available in 4ft x 8ft 1220mm x 2440mm and 4ft x 4ft 1220mm x 1220mm panels. 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. As a foil faced polyisocyanurate foam insulation enerfoil tm s r value actually more than doubles when it is twice as thick as you can see from the chart above. There is an exception provided that allows the minimum thickness to be up to 1 less than the prescriptive r value at per foot slope as long as the system r value meets or exceeds that prescriptive r value.

Closed cell polyisocyanurate polyiso foam core integrally bonded to non asphaltic fiber reinforced organic felt facers. In the nrca roofing manual. Acfoam ii is offered in a variety of thicknesses providing long term thermal resistance lttr values from 5 7 to 26 8. 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.

Recognized by the iecc. Membrane roof systems 2011 and the nrca roofing manual. Firestone isogard hd composite cover board is ideal for both new construction and reroof applications with available thicknesses from 1 5 to 4 two board sizes and three coated glass facers that provide mold resistance. It is a thermoset closed cell foam that is an optimal insulation solution for low slope roofs.

Zone 6 requires an r 30 minimum which is 5 2 thick. It can also be used as a roofing cover board and in building envelope applications. Furthermore nrca recommends design ers specify polyisocyanurate insulation be manufactured to have a minimum 20 psi compressive strength grades 2 or 3 and have facers that are compatible with the assembly method and other roof assembly. Dated its r value recommendations for polyisocyanurate insulation used in roof systems.

Membrane roof systems 2015 nrca had recommended designers use in service r values of 5 0 per inch thickness in predominant. This product provides two layers of insulation installed in one application which reduces labor and material costs. Benefits of energyguard polyiso roof insulation include. Polyiso has a high r value per inch compared to other insulation products.