ACFoam CrossVent from Atlas Roofing Corp. is an environmentally friendly polyisocyanurate-foam insulation board designed for use over sloped, unventilated roof decks. The product promotes air circulation with vent spacer strips that separate it from 7/16-inch (11-mm) oriented strand board. Installation can be completed without a thermal barrier directly on the roof deck. (800) 933-1476 /