The combination of asphalt, modifiers and reinforcements determines the characteristics of a specific modified bitumen membrane. To obtain the best roofing system possible, the designer, building owner and contractor should understand the dynamics of the roof as well as the roofing system when specifying either APP or SBS modified roofs.

The architect, specifier, building owner and roofing contractor should examine the following parameters when choosing a roofing system:

  • What is the building’s type and usage?
  • What building code requirements apply to the system?
  • What is the estimated service life of the roof system?
  • What type of maintenance will be required to maximize the service life of the roof system?
  • What kind of roof deck will be used (type, size, slope)?
  • How much is the roof deck expected to move relative to the roof perimeter? Shrinkage of the deck material? Moisture content of the deck?
  • Access for equipment on the roof?