Radiant barrier material for use in an attic insulation and ventilation system

A radiant heat and spray foam insulation barrier and ventilation air flow plenum assembly consisting of:

• a flat topmost layer consisting of a radiant barrier reflective surface having an emissivity rating of 0.1 or less;
• a bottommost layer consisting of a fire-resistant wavy surface;
• a heat-resistant first adhesive rated to at least 325° F.;
• a water-resistant second adhesive;
• and
• a flat middle layer consisting of a fire- and water-resistant flat kraft linerboard bonded by the first adhesive directly to an opposing inward-facing surface of the flat topmost layer and by the second adhesive to a contacting opposing inward-facing surface of the bottommost layer;
• the radiant heat and spray foam insulation barrier and ventilation air flow plenum assembly:
• capable of forming a bottom of a ventilation air flow plenum, the ventilation air flow plenum located adjacent to an underside of a roof decking and extending between adjacent roof rafters from a lower soffit vent to an upper roof vent and to another lower soffit vent;
• and
• is oriented so the flat topmost layer is roof deck-facing to reflect radiant heat entering the ventilation air flow plenum and the wavy bottommost layer is attic floor-facing to receive spray foam insulation.