This photo shows how I restored and protected the details of an existing roof line. I won't go into the details regarding why I did not cut back the fascia boards. What I want to bring to your attention are flashing details. Each board was flashed and, get this, counter flashed. To counter flash, I make thin kerf cuts in the fascian and freeze boards using my DeWalt oscillating cutter. Into these cuts I slipped custom-formed, L-shaped counter flashing. Kerfs were sealed (Lexel) and painted. The details of the original design are left undisturbed, and the flashing is barely visible from the street.
Mel Fros froscarpentry.com