Energy-saving protected roof systems

Abstract

A roofing system for a structure having a roof deck with upstanding edges about the perimeter of the roof deck, includes a waterproof membrane on the roof deck and extending from edge-to-edge. A reservoir is defined by the waterproof membrane and edges and may contain a liquid therein, but some embodiments may operate without the reservoir. At least one insulating panel is provided above the liquid reservoir and covers the waterproof membrane on the roof deck from edge-to-edge. A pump has an inlet within the reservoir and an outlet communicating with the surrounding environment for selectively spraying liquid from the reservoir or other source onto the external surface of the panel to cool the liquid in the reservoir. Drains in the panel provide communications between the external surface of the panel and the reservoir for permitting drainage of liquid on the external surface into the reservoir. An overflow drain established a maximum depth of the reservoir, and is located below the external surface of the panel so as not to be clogged by debris. An edge cushion between the edge and the insulation panel is resilient for accommodating reciprocal movement of the panel toward and away from the edge. The roof membrane continuously extends from the roof deck and surrounds an exterior face to the edge cushion extending between the panel and the edge to define the liquid reservoir and seal the roof deck against leakage.