Over the past few decades there has been a shift from multi-ply or built-up roofing options (BUR), which require layers upon layers of asphalt and roofing feels to a single ply roofing system. This roof installs one thermoplastic, PVC or ethylene layer directly on top of insulation. Both are durable and long-lasting. BUR roofing has many advantages, but a single ply roofing system is more popular.
