Part of Super FOIL's next generation of highly specified multifoils with unrivalled thermal performance Super FOIL SF40 is comprised of 37 layers including reinforced heavy duty double-foil outer layers & provides a 3-in-1 insulation solution with radiant barrier vapour control layer delivering a Thermal Resistance of up to 3.47R in a roof construction. Suitable for use in Roofs Walls & Floors in new build & retrofit SF40 is fully certified by BBA agrément LABC & LABSS.