These roof systems are commonly referred to as "tar and gravel" roofs. BUR systems generally are composed of alternating layers of bitumen and reinforcing fabrics that create a finished membrane. We have improved on that system over the years including our most recent product additions called PolaraLUM™ or our new Polastic™ finishes. The number of plies in a cross section is the number of plies on a roof: The term "three plies" denotes a three ply roof membrane construction. Sometimes, a base sheet, used as the bottommost ply, is mechanically fastened. Built up roofs generally are considered to be fully adhered if applied directly to roof decks or insulation.
The reinforcing fabrics also are called roofing felts or ply sheets and that is what Polara(TM) Product delivers. The bitumen typically used in BUR roof systems is asphalt, or cold-applied adhesive. The asphalt is heated in a tanker and then applied by mop or mechanical spreader. Asphalt is a petroleum product refined from crude oil; Cold-applied adhesives typically are solvent-based asphalts that don't have to be heated in a kettle or tanker. Most roofs are hot applied or we use one of the other systems that Hageman Roofing offers.
Surfacing for built up roof systems include aggregate (such as gravel, slag or mineral granules), glass-fiber or mineral surfaced cap sheets, hot asphalt mopped over the entire surface, aluminum coatings or elastomeric coatings.
The Built Up Roofing is often the most cost effective and durable roof of our offerings with roofs lasting often 30 – 40 years with minor maintenance.