Modified Roofing (SBS and APP)

Modified bitumen membrane roofs are installed in a number of configurations. Generally speaking, they are installed as either conventional systems – where the membrane is installed on the top side of the system, to protected membrane assemblies (PMA) or IRMA’s (inverted roof membrane assemblies), where the membrane is installed on the bottom of the system, with some form of overburden installed over top.

Almost all modified bitumen membrane roofs in the commercial roofing space today are constructed with a form of adhesive, whether it be hot, cold, or torch-applied.

Hot applied systems are installed with hot asphalt, heated from a piece of equipment on the ground and piped up to the roof level. The hot asphalt is mopped out and the modified membrane is set into this hot asphalt, providing the bond.

Cold-applied systems are adhered with (usually asphalt-based) adhesive that is applied with a trowel or squeegee. Cold applied systems remove the need for a hot asphalt kettle or an open flame on the job site.

Torch-applied systems are installed with the use of a propane torch, where the asphalt is pre-coated on the roll. The roll is heated with the torch to a specific temperature in which the asphalt on the roll becomes sufficiently soft, providing adhesion.