Built Up Roofing Systems
Built Up Roofing (BUR) Membranes are typically found on flat or nearly flat roofed buildings. These Membranes are referred to as built-up due to a process of overlapping several layers of roofing felts with hot or cold adhesives. BUR felts can be made of organic, fiberglass or polyester composition. The hot adhesives will be one of three main types: asphalt, modified asphalt or coal tar pitch. The cold adhesives are either asphalt or coal tar pitch based. A layer of gravel is typically the final step which protects the roof from ultraviolet degradation and provides weather resistance.
