Direct Answer
A leak around the chimney is almost always failed chimney flashing — the step flashing up the sides and the counter-flashing sealed into the mortar. When the flashing ages, lifts, or its sealant dries out, water runs down the chimney and behind the flashing into the house. Re-sealing is temporary; proper re-flashing is the lasting fix.
The roof-to-chimney junction is one of the most leak-prone spots on a home. Chimney flashing has two parts: step flashing that interweaves with the shingles up the sides, and counter-flashing cut into the brick mortar to cover the step flashing's top edge.
How It Fails
- Sealant at flashing edges dries out and cracks
- Step flashing lifts or loosens from the shingles
- Counter-flashing separates from the mortar joint
- Wide chimneys without a cricket trap water on the uphill side
Signs & Symptoms
- Water stain on the ceiling or wall near the chimney
- Dampness on the attic side of the chimney
- Leak during rain on the chimney side of the house
- Dried or cracked sealant visible at the flashing
Repair Options
- Re-seal the flashing (temporary)
- Re-flash the chimney with new step and counter-flashing (lasting)
- Add a cricket on wide chimneys to divert water
When to Call a Roofer
Any water near the chimney means the flashing needs inspection. Don't wait — chimney leaks can damage framing and interior finishes.
How Beyond the Ladder Handles It
We re-flash chimneys properly with step and counter-flashing sealed into the mortar, and add a cricket where the chimney width calls for one.
Related Questions
Can chimney flashing be repaired without re-flashing?
Re-sealing buys time but isn't lasting. The durable repair is re-flashing with new step and counter-flashing properly sealed into the mortar joints.
What is a chimney cricket and do I need one?
A cricket diverts water around the uphill side of a wide chimney. Wide chimneys should have one; narrow ones usually don't need it.