What Causes Chimney Leaks?

Chimney leaks are common because the stack is one of the most exposed parts of the roof and has several vulnerable junctions.

By Max, Surrey Roofing & Windows Ltd | Updated May 2026

Chimney leaks are common because the stack is one of the most exposed parts of the roof and has several vulnerable junctions.

Lead flashing failure

Lead flashings, soakers and back gutters protect the joint between roof and chimney. If they split, lift or are poorly dressed, water can track into the roof.

Pointing and flaunching defects

Open mortar joints and cracked flaunching around chimney pots let water into the stack. This can show as damp patches, stains or leaks during wind-driven rain.

The leak may not be the chimney itself

Valleys, tiles and felt nearby can also send water towards the chimney area. A proper inspection checks the wider roof detail.

Useful next steps

If you need roofing advice for a Surrey property, start with the relevant service page: roof repairs, emergency roof repairs, flat roofing, roof replacement or roof surveys. We also cover towns including Weybridge, Cobham, Woking, Guildford and Epsom.

FAQs

Can chimney leaks be repaired without rebuilding the stack?+
Often yes. Leadwork, pointing and flaunching repairs solve many chimney leak problems.
Do you repair chimney leadwork?+
Yes. We repair and replace chimney flashings, soakers and related roof details.
Need a Surrey roofing quote?Call 07565 812922 or use the free quote form. For active leaks, call now so we can triage the issue quickly.