Drains – APP A strip of Flintlastic APP modified bitumen large enough to extend a min. of 4" beyond the lead flashing edge in all directions (min. 40" x 40") is applied to the base sheet at the drain area. A min. 30" x 30" lead flashing is installed next. Over the primed flashing the field roof membrane is applied in normal fashion. The drain opening should be cut out while the membrane is still warm and the edges sealed. Set the drain cap in place and secure the clamping ring. If two field plies of Flintlastic APP modified bitumen mem- brane are used, the first field ply takes the place of the 40" x 40" flashing ply.
Drain detail, torch applications – part A
Drain detail, torch applications – part B