Johns Manville Foil Faced Polyiso Foam Insulation 2" x 4' x 8' R-13. Features. 4' x 8' sheet; One side has a reflective foil face typically installed toward the warm air surface to reflect energy back toward the dwelling and the other side has a white non-reflective foil face typically installed toward the exterior.Armaflex light-weight, closed-cell, 1/2", 3/4", or 1" thick, 3' x 4' foam thick sheet insulation is great for both indoor and outdoor installations and works as both an insulator and vapor-retarder by retarding heat gain and controlling condensation drip from chilled water and refrigeration systems.Insulation is an extruded polystyrene foam insulation board that is scored longitudinally on 16” and 24” centers, making it easy to size to commonly used widths. STYROFOAM™ Brand Scoreboard Insulation has excellent insulating characteristics, high resistance to water and water vapor, exceptional compressive strength and long-term durability. Durable Cladded Insulation in Sheets and Rolls. ArmaTuff is the one-step installation solution for thermal mechanical insulation and UV protection of exterior ducts, tanks, vessels, large pipes and fittings. The combination of a tough metal cladding laminated to Armaflex® closed-cell foam insulation provides durable, year-round weather protection.Starting in year five and for the remaining life of the insulation, the R-values of polyiso spray foam and XPS including STYROFOAM™ sheets are below LTTR published R-values. 50 YEAR R-VALUE Most insulation users are interested in a true long-term thermal R-value for their insulations.Choose from our selection of insulation sheets, including over 425 products in a wide range of styles and sizes. In stock and ready to ship.