Flat Roof Leak Near the Chimney: A Very Common Pattern
BERKELEY FLAT ROOF BLOG
Flat Roof Leak Near the Chimney: A Very Common Pattern
Chimneys are one of the most common flashing failure points on any roof, flat or pitched.
A chimney passing through a roof needs counter-flashing set into the masonry to keep water out — and that flashing detail is exposed to the same freeze-thaw and thermal cycling as the chimney itself, which can work the seal loose over time. It’s a genuinely common failure point, not a sign of anything unusual about your specific chimney.
The fix is resealing the actual groove where the flashing meets the masonry, not just caulking over the visible gap — caulk alone doesn’t hold up on a roof long-term.
Leak showing up near your chimney?