Johns Manville AP Foil-Faced Polyiso Continuous Insulation board consists of a uniform closed-cell polyisocyanurate foam core bonded on each side to a foil facer. One side has a reflective foil facer and the other a white non-reflective foil facer, allowing the installer to orient the board to suit the application. Polyiso provides one of the highest R-values per inch of any rigid insulation — R-6.0 at one inch — making AP Foil-Faced a go-to choice for above-grade wall continuous insulation.
When properly installed and sealed, AP Foil-Faced functions as a water-resistive barrier, vapor barrier, and air barrier — eliminating the need for additional WRB/AB components in many assemblies. It offers R-values up to R-28 in standard thicknesses, carries an ASTM E84 Class A rating, and has been tested in multiple NFPA 285-compliant exterior wall assemblies.