Polyisocyanurate Foam Insulation R Value

Johns manville r panel rigid roof insulation board offers r values of up to r 23 6 providing high thermal efficiency.

Polyisocyanurate foam insulation r value.

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. Excellent lttr value compared to any other fm class 1 rated products of equivalent thickness. Cost polyiso is the most expensive of the foam board insulation products however it s the highest r value. 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.

During late 2014 nrca conducted additional limited r value testing of polyisocyanurate insulation and found r values lower than the current lttr values. Polyisocyanurate polyiso is a closed cell rigid foam board insulation that is bonded to facers on both sides which are composed of various organic and inorganic materials. Polyiso insulation is the best choice as a cost effective energy efficient and environmentally responsible insulation product. Polyiso s unique benefits include highest r value per inch.

The results also are somewhat lower than the results at 25 f 40 f 75 f and 110 f mean test tem peratures from nrca s 2009 testing. Keep in mind that polyiso s r value increases with thickness. A true environmental winner polyiso is a good choice for leadership in energy and environmental design leed credits. Polyiso has a high r value per inch compared to other insulation products.

Polyurethane and polyisocyanurate are both closed cell foams. On tuff r insulation one facer is a continuous sheet of aluminum foil. An insulation material s resistance to heat flow is rated in terms of r value a higher r value means greater insulating effectiveness i e higher resistance to heat flow. So you need to know an insulation product s thickness as well as its r value in order to compare it to another product.

The other is a tri plex facer consisting of a three ply laminate of durable kraft. They contain low conductivity gases in the cells usually one of the hcfc or cfc gases. 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. R panel is manufactured with a closed cell polyisocyanurate foam core bonded to fiberglass reinforced facers and designed for use over metal nailable and non nailable roof decks with a variety of membrane systems.