HIGH DENSITY POLYURETHANE AND POLYISOCYANURATE CONSTRUCTION BOARDS AND COMPOSITE BOARDS

摘要

A covered low-slope or flat roof comprising (a) a roof deck, (b) an optional insulation board including a polyurethane or polyisocyanurate cellular structure having a density that is less than 2.5 pounds per cubic foot, (c) a coverboard including a polyurethane or polyisocyanurate cellular structure having a density greater than about 2.5 pounds per cubic foot, and (d) a membrane.