Construction of Experimental Modified Bitumen Roofing at Fort Polk, LA

This report describes the initial construction phase of test roofs at Fort Polk, Louisiana, as part of a projected 10-year field evaluation of modified bitumen roofing systems. This work is part of a research effort to identify alternative, easy-to-install roofing systems that can improve the performance of Army roofing while reducing life cycle costs. Three different modified bitumen roofing systems were installed on Building 920 at Fort Polk. To determine performance, samples from the test roofs will be laboratory tested and the roofs will be visually inspected annually for 10 years. Most modified bitumen products use one of two different asphalt modifiers atactic polypropylene APP or styrene butadiene styrene SBS. Manufacturers use different reinforcing materials e.g., polyester, glass fiber mats. Modified bitumen membranes commonly are installed by torch-fusing, hot asphalt embedment, or self-adherence. The test plan was designed to determine how weathering would change the physical and mechanical characteristics of the membrane materials and compare the results between the different types.