Polyisocyanurate is among the most common way to insulate a commercial buildings' flat roof. It is a thermoset plastic manufactured as a rigid foam board that can be installed over wood, steel, or concrete substrates without the need for an additional thermal barrier. In addition to its thermal properties, it is also used to move standing water from a roofs' surface. A properly designed tapered Polyiso roof adds value to your investment, lowers heating and cooling costs, and protects the roof surface by pitching otherwise standing water which can rapidly degrade the material. 

Insulation and Recovery Boards