Modified Bitumen systems consist of asphalt with modifiers added to give it durability. These are either one, two or three ply-systems. They are factory manufactured and combine the redundancy of built up roofing with the ease of application of a single-ply system.
SBS (Styrene Butadiene Styrene) systems are usually installed with hot asphalts, cold adhesives or self-adhering peel and stick applications. Modified bitumen roof systems can be finished with a variety of surfaces that enhance their resistance to oxidation and damage from UV rays.