Why Is My Roof Leaking Around the Chimney?
For water marks, drips or damp around a chimney breast or nearby ceiling that become more noticeable during or after rain.
What this usually means
The joint where a chimney passes through the roof has to be weathered carefully, usually with flashing. If that flashing is loose, split or poorly detailed, rain can enter around the stack. But the leak can also come from cracked chimney masonry, failed pointing or flaunching, damaged tiles, or another roof defect slightly uphill from the stain. The safest homeowner job is to record when the leak happens and inspect from the ground or a safely boarded loft — not to climb onto the roof.
What may be causing this
Loose, split or failed flashing around the chimney
Clues: Damp appears close to the chimney after rain. From the ground, flashing may look lifted, displaced or separated from the masonry, although small defects can be impossible to see safely.
What to do: Have a roofer inspect the chimney abutment and flashing detail. Historic England identifies leaking chimney/lead flashing as a repairable source of damp, and proper flashings weatherproof the roof-to-chimney junction.
Cracked pointing, brickwork or flaunching on the stack
Clues: The chimney shows open mortar joints, cracking, loose masonry or deteriorated material around the pots. Damp may track down the chimney breast rather than appearing exactly at the roof line.
What to do: The stack needs close inspection and repair by someone competent to work at height and with chimney masonry. Repointing or local masonry/flaunching repair may be needed alongside the flashing.
A slipped, cracked or poorly detailed roof tile nearby
Clues: The visible defect is just above or beside the stack, or the leak changes with wind direction. Water can travel along underlay or timbers before it appears indoors.
What to do: A roofer should inspect the surrounding roof covering as well as the flashing so the visible indoor stain is not mistaken for the exact entry point.
Condensation rather than rain penetration
Clues: The area is damp without a clear relationship to rainfall, especially in a poorly ventilated cold roof space. Moisture may be more diffuse than a single rain-linked track.
What to do: Have roof ventilation and moisture conditions checked. Marley notes that water-ingress concerns can sometimes be condensation related rather than a simple covering defect.
How to check what is happening
External water entry becomes much more likely than condensation or a one-off historic stain.
The chimney/roof junction, stack masonry or adjacent roof covering deserves priority inspection.
You have a useful clue for the roofer, but a ground view cannot rule out smaller defects on the hidden sides of the chimney.
That helps confirm active roof-level moisture and may show the direction water is tracking before it reaches the ceiling.
Can you fix this yourself?
You can contain drips, photograph the stain, compare it with rainfall and inspect from ground level or a secure boarded loft. Do not climb onto the roof or attempt a temporary flashing repair from a ladder. Chimney details are high-risk access points and the visible indoor stain may not be directly below the actual entry point.
- Phone camera
- Bucket or waterproof container
- Torch
- Binoculars if already available
What you can safely try
- 1
Protect the room from further water damage
Move belongings away from the wet area and place a container below a safe drip point. Do not stand beneath a sagging ceiling and do not puncture wet plasterboard.
- 2
Record exactly when the leak appears
Note whether it happens in light rain, only in heavy rain, or mainly with wind from one direction. Take photos of the stain before and after rainfall so the roofer can see the pattern.
- 3
Map the stain against the chimney breast
From inside, note whether the mark follows the chimney itself, sits beside it on the ceiling or appears some distance away. Water can track, so this is a clue rather than proof of the entry point.
- 4
Inspect the chimney and nearby tiles from the ground
Look for obviously displaced flashing, open mortar joints, cracked masonry, slipped tiles or vegetation. Use zoom or binoculars if helpful; do not climb a ladder to get a closer look.
- 5
Check the loft only from a safe boarded position
If the loft is safely accessible and boarded, use a torch to look for wet timbers, underlay or masonry around the chimney after rain. Never step between joists onto the ceiling below.
Call a roofer if…
- The chimney, pot or masonry looks loose, leaning or unstable.
- The ceiling below is sagging, heavily soaked or actively shedding material.
- Water is reaching electrical fittings, wiring or equipment.
- Access would require climbing onto the roof, an unsecured ladder or an unboarded loft.
- The leak continues after an attempted roof repair or the entry point remains unclear.
Get the right roofer.
We already know this problem maps primarily to a roofer. Choose the closest type of work, add your postcode and continue in the form.
Sources used for this guide
We prefer primary UK guidance, regulators and manufacturers for technical and safety-sensitive claims.
- Repair or Renew the Roof in an Older HomeHistoric England
- Maintenance ChecklistHistoric England
- How do I protect roofs from rainfall?Marley
- Guidance for re-roofing projectsHorsham District Council
Last reviewed: 30 August 2026. Home Manual updates review dates only when the substance of a guide is checked or changed.