There are eight major families of commercial roofing systems: steep slope, built-up roofs (BUR), modified bitumen, metal, roof coatings, foam, thermoplastic single-ply membranes (TPO and PVC) and thermoset single-ply membranes such as EPDM. Each commercial roofing system has its own performance characteristics and distinct advantages. SMART Roofing is a commercial roofer that has worked extensively to install, maintain and repair each of these roof systems.