H-Shield NB is a rigid roof insulation composite panel composed of a closed-cell polyisocyanurate foam core manufactured on-line to a fiber reinforced facer on one side and either 7 ⁄16" or 5 ⁄8" oriented strand board (OSB) on the other. H-Shield NB can also be manufactured off-line bonded to 5 ⁄8" or 3 ⁄4" plywood.