#2312 • (18) 4'x4'x2.6" EnergyGuard Polyiso Insulation Sheets Part of GAF EnergyGuard Polyiso Insulation: 4'x4' and 4'x8' (163709) (timed auction by Bid-2-Buy) Status: Sold 2.6" 20 PSI (18) Pieces = 576 Sq. Ft.