value. Many additional benefits exist such as durability, longevity, lightweight, self-flashing, and strength especially with pre-engineered metal buildings. SPF is applied as a liquid using two-component spray equipment as it is applied onto the roof surface filling cracks and crevices. It expands approximately 20 times its original liquid volume to form a hard, monolithic roof surface. The polyurethane foam dries within seconds after application and is fully adhered to the roof surface with a history of lasting more than 35 years as a maintainable roofing medium. Its expansion results in a weather-tight roofing that is not only light weight, adding little weight to the structure of the building, but increasing the insulation value of the roof a measureable amount which should be relected in the heating and cooling of the building.