Insulation panel for a roofing system or the like

A factory assembled, insulation panel for use in a roofing system or the like to insulate the interior of a building from ambient thermal cycling and for insuring water impermeable integrity of the building, said insulation panel being laminated and comprising:

• an insulating drainage course operable to be placed against a waterproofing roof membrane or the like, said insulating drainage course comprising,
• a generally homogeneous association of expanded polystyrene spheres fixed together at points of contact with random voids created throughout the association to render it both insulating and substantially porous to the passage of water, and
• said expanded polystyrene spheres of said insulating drainage course being coated with an outer film of latex bituminous emulsion, the coated spheres being resistant to the penetration of water interiorly within the spheres and concomitantly the latex bituminous emulsion being a waterproofing adhesive such that the spheres are fixed together at contact points to isolate the expanded polystyrene spheres from penetration by water and moisture and to adhere the spheres in a generally homogeneous association which is porous to the passage of water;
• an insulation course of closed cell synthetic polymeric material overlaying said insulating drainage course, said insulation course serving to thermally isolate a building and the waterproofing roof membrane from ambient thermal cycling;
• and
• a water and vapor barrier course co-extensively extending between said insulating drainage course and being composed of a self adhering polymeric emulsion such that said water and vapor barrier course protects said insulation course from penetration of water and water vapor and concomitantly adheres said insulation course to said insulation drainage course, wherein a factory assembled, insulation panel may be combined with other similar panels to form a roofing system or the like with an insulating and drainage course being operable to permit water which reaches a waterproofing membrane to migrate through the insulating drainage course to a drain while the insulation course is protected from water and vapor moisture by the water and vapor barrier course coextensively extending between said insulation drainage course and said insulation course.