Flashing is the material, usually metal, installed at roof joints and penetrations like chimneys and vents to keep water out. It is a small detail compared to the shingles or the deck underneath it, but it is one of the most common places a roof actually starts to leak. This guide walks through what flashing is, where it belongs on a roof, and what to look for when it starts to fail.
Flashing is installed anywhere a roof plane meets something else: a wall, a chimney, a skylight, a vent pipe, or another roof plane. Each of those transitions is a place where water can find a gap if the flashing is missing, undersized, or installed incorrectly.
Chimneys are one of the most leak-prone penetrations on any roof because they combine step flashing along the sides with counter-flashing set into the masonry. For a closer look at what causes chimney flashing to fail and how it gets fixed, see our dedicated chimney flashing leaks and remedies guide.
Because flashing sits at joints and transitions rather than across the main field of the roof, damage there is often hidden from the ground and even from a casual walk across the roof. Indy Roof & Restoration documents every inspection with photographs, so homeowners can see exactly where flashing has failed rather than taking a verbal description on faith.
Flashing issues are sometimes an isolated fix and sometimes a sign of broader roof age or damage. If you are trying to sort out whether a flashing leak points to a bigger issue, our roof repair page covers how we evaluate and address roof leaks in Indianapolis.
Flashing is the material, usually metal, installed at roof joints and penetrations like chimneys and vents to keep water out.