s a long-time metal roofer, I was always skeptical about flat roofs. I had an attitude change about low-slope applications, though, when I started using modified bitumen roofing a few years back. Commonly referred to as “torchdown,” thermally fused single-ply asphalt bitumen membrane was developed in Italy during the mid- 1960s as a lining for underground fuel and water tanks. Roofing was a logical next step, and torchapplied roofing systems began to be installed in Italy in the 1970s. Because rooftop conditions are much harsher than those underground, however, those early systems often failed by Rick Palmer A prematurely. The addition of specially formulated polymers gave the original membrane much better resistance to heat, cold, and UV, as well as improved elasticity, which is why
