EnergyGuard Perlite Roof Insulation

Credit: GAF Materials Corp.

What makes this product green?

  • Reduces heating and cooling loads


Perlite is an amorphous volcanic rock that is expanded at very high temperatures to create a lightweight insulating material typically used for loose-fill applications. GAF adds up to 50% cellulose fibers and up to 20% asphalt to bind the perlite together in its EnergyGuard boardstock insulation for roofing applications. With inherent fire resistance and insulating value of R-2.78 per inch, EnergyGuard provides an alternative to polystyrene and polyisoPolyisocyanurate foam is usually sold with aluminum foil facings. With an R-value of 6 to 6.5 per inch, it is the best insulator and most expensive of the three types of rigid foam. Foil-faced polyisocyanurate is almost impermeable to water vapor; a 1-in.-thick foil-faced board has a permeance of 0.05 perm. While polyisocyanurate was formerly manufactured using HCFCs as blowing agents, U.S. manufacturers have now switched to pentane. Pentane does not damage the earth’s ozone layer, although it may contribute to smog. boards. It is installed directly on top of a structural roof deck. GAF designed the product for use under built-up roofing or modified bitumen, so some single-ply roofing membranes may not be compatible with it. GAF offers the boards in standard 2'x2' and 4'x4' sizes and 3/4", 1-1/2", and 2" thicknesses.

Manufacturer Information

GAF Materials Corp.
1361 Alps Rd.
Wayne, NJ 07470
Phone: 973-628-3000
Fax: 973-628-3865
Toll-free: 800-766-3411

Listed in: Board Insulation


Jun 16, 2017 5:07 AM ET

Response to Vija Handley
by Martin Holladay

The product described on this page has an R-value of R-2.78 per inch.

Jun 15, 2017 10:46 PM ET

looking for r values of
by Vija Handley

looking for r values of insulation board