Chimneys and parapets
A chimney apron is tucked under the slates the wrong way. Has that detail been water-tested?
No. That detail has not been water-tested. A chimney apron is tucked under the slates the wrong way, so the metal that should dress over the slates below the stack appears to run underneath them, which can lead rain back under the covering. The survey saw the arrangement from the access it had. It did not run water over the apron, did not lift the slates, and has not decided how much rain the detail lets in. The back-tuck is a visible fault of detailing. It is not a measured leak test.
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?
An apron should shed water onto the slates, not tip it into the joint beneath them. Tucked the wrong way, it forms a path into the roof whether or not a ceiling is stained today. The survey can report the orientation because it could see it. It cannot report a volume of water, because no water was put on the detail and the slates were not lifted. The defect is the tuck itself.
Ask a roofer to correct the dressing and to check the timbers under it, as work beyond this survey, and keep their note separate. Tell a lender the apron is tucked the wrong way and was not water-tested. Do not describe the chimney flashing as weathertight, and do not invent a leak rate. The report's finding is the detail. The amount of water it admits is still unknown.
What should you ask your surveyor?
- Was water run over the back-tucked apron?
- Were the slates lifted to see the path underneath?
- Is the wrong tuck being reported as a measured leak?
What are the typical next steps?
- Treat the apron as a detailing fault that was not water-tested.
- Ask a roofer to redress it and check the timbers beneath.
- Do not describe the flashing as weathertight.
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 a dry ceiling clear the back-tuck?
No. A dry ceiling means no stain was showing inside. It does not test the apron, and the apron was not water-tested. Rain may not have been driven at that face for some time. The wrong tuck remains a path whether or not the ceiling has marked. Do not clear the detail from a dry room.
Can lead sealant painted over the tuck replace redressing it?
The survey has not specified a repair. Paint or a smear over a back-tuck would be someone's proposal, not a test, and it was not assessed here. The finding is that the apron is the wrong way and was not water-tested. A proper redress is a later job. Do not let a coating stand in for that.