GAF, North America’s largest roofing manufacturer, announces the production of high-density polyisocyanurate(ISO) cover boards, which can be used as a protective layer over boardstock insulation or as a recover over an existing roofing system. These cover boards offer superior roof protection from foot traffic, storms, and hail, while also offering the benefit of being easy to install due to their light weight.
GAF offers two versions: HD with over 80 psi, and HD PLUS with over 110 psi compressive strength and a durable coated glass facer. Each of these boards is an ideal choice for protecting your roof from the elements and rooftop traffic. GAF EnergyGuard™ HD is a ” thick high-density ISO cover board with an R-value of 2.5, the highest of any cover board—and, at 11lbs.(HD) 13lbs.(HD PLUS) per 4’ X 8’ board, it’s a fraction of the weight of gypsum cover boards.
http://www.gaf.com/About_GAF/Press_Room/Press_Releases/164691968