This is a modified bitumen flat roof. Normally the cap sheet would be run up the curb and then a flashing (made out of cap sheet) would be applied over that. I would extend it 6 inches on the roof and all the way up and over the 2x4 flashing.
When installing a new curb on an old roof, do I just flash with a cap sheet and not worry about the roof cap sheet running up the curb? Should I make the cap sheet flashing extend further on the roof?