The two broad categories of asphalt roofing systems for commercial, industrial and institutional buildings are Built-Up Roofing (BUR) and Modified Bitumen Systems (MBS).
Built-Up Roofing: Built-up roofing systems have had a long-standing popularity, due in large part to the success and proven reliability of BUR. The stock of 20, 30 and 40-year-old BUR roofs still in excellent condition attests to this fact. Specifically, BUR roofs offer:
- Multi-Layer Protection -- the multiple layers of bitumen and bitumen saturated "felts" make a watertight barrier capable of providing many years of reliable protection from the elements
- Thermal Performance -- Built-up roofing systems exhibit exceptional resistance to the conduction of heat between the exterior and interior of a building, resulting in noticeable reductions in heating and cooling costs.
- Fire and Uplift Resistance -- Built-up roofing systems are tested through Underwriters Laboratories and Factory Mutual Research Corporation to meet very strict fire resistance requirements and ensure adequate uplift resistance under extreme wind conditions.
- Economy -- Compared to other high performance commercial roofing systems, built-up roofing is one of the best investments on the market due to its competitive cost per year of expected service life.
Modified Bitumen Systems: Since gaining acceptance in the roofing industry during the 1970s, the use of modified bitumen membrane roofing systems has increased steadily. Today modified bitumen membranes are the fastest growing roofing materials in the industry.
Considered a quality “hybrid” system, MBS provides the features of a built-up roof with the added tensile strength and elongation of a modified bitumen cap sheet, as well as the quality assurance of in-plant membrane fabrication uniformity and control, and reduced labor requirements for installation.