Roof problems
Roof leaking around the chimney: causes and fixes
Most leaks around a chimney come from failed flashing, the metal that seals the joint between the chimney and the roof. Cracked mortar, a damaged chimney crown or a missing cap can also let water in. A lasting fix replaces the step and counter flashing, which is why a full chimney reflash is part of our Core and Complete options.
Updated September 14, 2026
Where the water gets in
- Step flashing: the L-shaped pieces woven into each course of shingles along the sides of the chimney
- Counter flashing: the metal set into the mortar joints that covers the step flashing
- The crown: the concrete cap on top of the chimney, which cracks over time
- Mortar joints and brick, which absorb more water as they age
How to tell what’s leaking
If the stain appears only during heavy, wind-driven rain, flashing is the usual suspect. If the brick looks damp or streaked white from the outside, or the leak shows up after long, steady rain, the masonry or the crown is more likely. A leak on the downhill side of the chimney often means water is getting behind the flashing on the uphill side.
Why sealant doesn’t last
Caulk and roofing cement over old flashing can stop a leak for a season, but they dry out and crack as the chimney and the roof move differently with temperature. Replacing the flashing when the roof is replaced is the durable fix, and it costs less than doing it separately later.
Questions
- Can chimney flashing be fixed without replacing the roof?
- Sometimes, on a younger roof. If your roof is near the end of its life, reflashing now disturbs shingles that will be replaced soon anyway, so doing both together usually makes more sense.
- What if the problem is the chimney itself?
- Our roofing options cover the flashing. If the verification visit finds crown or mortar problems, we photograph them and tell you before you sign.
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