MODIFIED BITUMEN  (Torched Applied Roofing)

A commercial roofing waterproofing membrane either granulated or smooth surfaced composed of asphalts blended with polymers and reinforced with polyester fabric or fiber glass mat. Torch down refers to the application method of using heat from the torch to melt the adhesive embedded in the material. Hot mop refers to the application method of using hot asphalt from a kettle as the adhesive.

BUILD-UP ROOFING

Commonly referred to as a Tar & Gravel roof. By today's codes this commercial roofing consists of the use of steep asphalt (normally type III) instead of coal-tar pitch as used by our forefathers. The type of substrate dictates the type of insulation and base sheet materials to be used, ply's of felt (generally 3, 4, or 5) are installed by integrating hot asphalt between each ply installed, to build an overlapping, redundant system. This system is then flooded with more hot asphalt in order to seed the application of 400 to 600 pounds of gravel per 100 square feet (1 square).