Chimneys and parapets
What did the visit record about open joints in the flaunching, about the tallest pot, and about rain running down the flue?
The visit recorded open joints in the flaunching, named the tallest pot by sight, and described rain running down the flue as a path rather than a measured leak. Flaunching is the mortar crown that beds the pots and sheds water off the stack. Open joints are gaps in that mortar. The tallest pot is the one that stood highest as seen, not a height that was measured. The survey has not decided how much water enters, has not tested the flue lining, and has not said the pot must be reset.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
Sound flaunching slopes away from each pot so rain leaves the crown. An open joint breaks that slope, and water can track down the pot or the joint and into the flue. Describing rain running down the flue names that route. It does not measure the water, and it does not show whether any liner is holed. The tallest pot simply meets more weather. Being tallest is an identification, not a defect on its own.
Ask a roofing or chimney contractor to see the flaunching from the stack and to say whether the open joints need repointing and whether the tallest pot is still well bedded. Tell the solicitor the survey recorded a path for rain and did not measure it. A sweep or a camera inspection is a different job if the flue itself is in question. The lender has this description only. The home survey has not certified the crown of the stack or cleared the flue.
What should you ask your surveyor?
- Were the open joints in the flaunching seen rather than measured?
- Did you identify the tallest pot by sight only?
- Was rain down the flue a described path, not a measured leak?
What are the typical next steps?
- Record open flaunching joints and a rain path, not a measured leak.
- Ask a contractor to check the crown and the pot bedding from the stack.
- Keep any flue camera inspection as a separate instruction.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Does the tallest pot have to be the one that is failing?
No. Tallest means it stood higher than the others as seen. The open joints are in the flaunching around the pots, which is a different note. The survey did not single out the tall pot as unsound. Height alone has not decided which pot, if any, needs resetting.
Have open joints already proved a wet flue lining?
No. They show mortar that is open at the crown. Water may run down from there, and the report describes that path. The lining was not inspected. An open joint is not a test of parging, a liner or mid-feathers. The amount of water was not measured either.