In addition to the gutter edge flashing, your roof has flashings at many other critical points. These include fireplaces, the valleys in the roof, around skylights, around plumbing vents and anywhere roof and siding meet.
How to do it right: A common practice of many roofers is to replace some but not all of your existing flashings. This is not recommended. Re-used roof flashings are prone to leakage, and detract from the finished appearance of the new roof.
The edge of the roof that is next to the gutter needs special protection.
A strip of metal “flashing” is needed to protect the plywood.
How to do it right: A quality flashing at the gutter edge makes a big difference in reliability of your roof. The plywood next to the gutters is vulnerable to water saturation. Water that reaches the gutter can soak back up and result in moldy or rotting plywood on the eaves of your roof. To prevent this, gutter edge metal should be installed on every roof.