Why is my chimney leaking, and what should I do?
Short answer. Chimney leaks come from five places: the cap, the crown, the masonry, the flashing at the roofline, or condensation inside the flue. Start by containing the water and noting when it leaks, then call the right trade: a roofer for flashing and crickets, a mason for the crown, brick and mortar, and a chimney sweep for caps, flues and liners.
What to do now
- Put a pan or towels in the firebox or under the drip.
- Hold off on fires until it is checked if water has been running down the flue, since it can damage the liner and damper.
- Photograph the stains and note dates and weather.
Match the symptom to the source and the trade
- Water in the firebox: a missing or damaged cap, a cracked crown, or liner problems. Call a chimney sweep or chimney repair specialist.
- Stains on the ceiling or wall beside the chimney: roofline flashing or a missing cricket. Call a roofer.
- Damp patches on the brick inside or dark stains outside: porous brick or eroded mortar. Call a mason.
- Damp with no rain, and gas appliances venting into the flue: condensation. Call a chimney professional or HVAC technician.
- Framed chase with siding: the metal chase cover, the siding, or the flashing at the base. Call a roofer or siding contractor.
Insurance
A chimney leak from gradual wear is usually not covered, but sudden storm damage, such as hail-dented flashing or a cap blown off in wind, may be. Photograph storm damage and report it promptly.
Fix it once
Sealant smeared around the base of a chimney is the most common failed repair. A lasting fix replaces the failed part, whether that is a new crown, repointed joints, or new step and counterflashing. See chimney leaks and crickets and roof flashing explained.