Other innovations are the use of reflective granules and white cap sheets, and polymer products with a fleece back that can be fully adhered in asphalt. There are also cold-applied BUR systems, which use polymer-modified bitumen in the place of hot asphalt. The introduction of modified-bitumen membranes has helped to boost the image of asphalt roofing as a high-tech roofing system. These additives can be used to impart UV protection to the asphalt - for example, when the asphalt is used for a flood coat - or to adjust the melt point and viscosity, depending on the ambient temperature or roof slope, or to adjust the elasticity of the asphalt.
Also, there are more choices with regard to asphalt that has been modified with polymer additives. In common with many industries, quality control is better today, and users are assured of receiving a high-quality product whose properties are more tightly monitored and controlled. Asphalt has always been a good product, which is how it earned its reputation. Quality asphalt today is much the same as the high-quality asphalt that was used by past generations of roofers. That's hugely beneficial when you calculate your roof life-cycle cost. By using an ultra long lasting product, you could be adding five to 10 years of life to your roof.
This enables the contractor to schedule odor-sensitive jobs during typical business hours. Recent innovations have made it possible for some products to reduce up to 90 percent of asphalt fumes at the kettle. One perception with BURs is the smell that is often associated with this type of material.
BUR offers the added protection of redundant multiple layers, performs well in extremes of heat, cold, wind, and snow, is easy to repair, and has a proven track record. Built-up roofing has been used for more than 100 years and is extremely durable.