Application Koppers System 2000 membranes are recommended for both new construction and reroofing over approved substrates. APP membrane systems are applied using a propane torch while the SBS systems are installed in hot ASTM D 312 Type III or IV specification asphalt or approved modified bituminous adhesive. Rolls are laid perpendicular to the slope starting at the low point of the roof deck. Side laps are 4" (102mm) and end laps 6" (152mm). Backnailing is required on roof slopes exceeding 1" (25.4mm)/foot (304mm). Caution: Extreme caution must be exercised at all times when working with an open flame. At no time should an open flame be used on or near any combustible material. Always conform to all local fire codes and have fire extinguishers available on the job. Koppers recommends that at least one member of the roofing crew monitor each day’s installation at least one hour after completion to check for any smoldering areas.  Return to Koppers System 2000 Modified Bitumen Membranes