Glossary
Flashing
Sheet metal installed wherever the roof plane is interrupted or meets something else — a wall, a chimney, a valley, a vent pipe — to carry water back onto the roof surface.
In practice
Most roof leaks are flashing leaks. The field of a shingle roof rarely fails; the interruptions do. When a bid does not itemize flashing replacement, ask why — reusing old flashing on a new roof is a common and costly shortcut.