Roofs and flat roofs
The lead apron at the front of a chimney is lifted and the back gutter looks seated. What weather joint is open, and which one was not the problem?
The open weather joint is the lead apron at the front of the chimney. Wind has lifted it, so the overlap that should dress down over the tiles is no longer tight, and rain can get in at that face. The joint that was not the problem is the back gutter, which looked seated. The survey has separated the two. It has not lifted the seated gutter to prove it, and it has not redressed the apron. A lifted front apron is the open joint. A back gutter that still sits is not the defect this note is describing.
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 is the lead at the front of a stack, dressed over the tiles below so water running off the chimney sheds onto the covering. If wind lifts that lead, the crease opens and water can track under the tiles at the front only. The back gutter is the channel behind the stack, and a seated one is still lying in its place. It is enough to stop you blaming the back gutter for a defect the survey put on the front apron.
Ask a roofer to redress or renew the lifted front apron, and to check the front abutment while they are there. Tell them the back gutter looked seated, so they should not treat it as the failed joint unless they find otherwise. Tell the solicitor the open weather joint is the front lead. The survey has not redesigned the flashing and has not water-tested the gutter. The work is the apron the wind has already lifted.
What should you ask your surveyor?
- Is the lifted lead apron at the front the open joint?
- Did the back gutter look seated, and so not the joint in this note?
- Was neither joint water-tested?
What are the typical next steps?
- Treat the front apron as the open weather joint.
- Leave the seated back gutter as not the defect in this note.
- Ask a roofer to redress the lifted lead.
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
If the loft is dry under the front apron, has the lead dropped back?
A dry loft on the day does not reseat a lifted apron. The survey saw the front lead raised by the wind. The back gutter looking seated was the joint that was not the problem. Dry timber can change when rain is driven at the open crease. The report has not said the apron has gone back. It recorded it lifted.
Should the back gutter be replaced because the apron has lifted?
Not on this note. The back gutter looked seated, and it was not the problem. The open joint is the front apron. Replacing a gutter that was recorded as sitting would be a different decision, made by a roofer who finds a reason the survey did not give. Deal with the lifted lead. Do not swap the two details.