General Rules for the Construction of Flashing. Construction of flashing should follow the general procedure outlined below. Type IV Asphalt or Matrix SB Trowel Grade with built-up and SBS roof systems. Use torch applied flashing membranes for APP products. Gravel stop edging, and other metal sandwiched between roofing materials requires regular maintenance to insure a watertight condition at the flashing.
Maintenance is the responsibility of the building owner.