Roofing Guide
Roof Flashing Problems and Why They Cause Leaks
If your roof is leaking, there’s a good chance the flashing is to blame. Here’s why this unglamorous metal matters so much.
What is flashing?
Flashing is thin metal installed at the joints and edges of your roof — around chimneys, against walls, in valleys, and around skylights and vents. Its job is to direct water away from these vulnerable seams. Shingles shed water across the field of the roof; flashing handles everywhere they can’t.
Why flashing fails
- Age & corrosion — older metal rusts and degrades
- Poor installation — improperly lapped or sealed flashing leaks from day one
- Movement — expansion, contraction, and settling loosen it
- Failed sealant — caulk used as a shortcut dries and cracks
- Storm damage — wind lifts and bends it
The telltale signs
Leaks that appear near a chimney, skylight, or where a wall meets the roof are classic flashing leaks. So are rust streaks and visibly lifted or gapped metal.
The fix
Good flashing repair means proper metal, correctly lapped and integrated with the shingles — not a smear of caulk. See roof repair and leak repair, or call (347) 400-9473.
Related reading: Common causes of roof leaks
Leak near a chimney or skylight?
Mariani Roofing repairs flashing the right way across LI, NYC, and New Jersey.