Outbuildings and conservatories
A conservatory dwarf wall is bolted to the house and no damp-proof course was visible in that wall. What moisture path is unverified at the bolts?
The moisture path at the bolts is unverified, because the dwarf wall is fixed to the house and no damp-proof course was visible in that wall. Bolts through the junction can link the conservatory masonry to the house wall. Without a visible course, the survey cannot say moisture is stopped at that line, and it also cannot say the bolts are already carrying damp indoors. It has seen the bolts and the absence of a visible course. It has not opened the joint, has not traced a damp line into the house, and has not decided that the bolts are the active path.
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?
A dwarf wall should have its own damp-proof course, and the junction with the house should not give ground moisture a route into the main wall. Bolts are metal fixings through that junction. If they pass from a wall with no visible course into the house, they are a possible bridge, not a proved one. The survey looked. It did not dismantle the bolts or the flashing, and it did not meter a hidden path it could not see. Unverified means the route is still a question.
Ask a damp specialist or a conservatory contractor to look at the junction if you need the path confirmed, and keep that apart from the survey's limit. Tell the solicitor the course was not visible and the joint was not opened. Do not let a seller's claim that the conservatory was damp-proofed stand in for a course nobody saw. The report has not cleared the house wall at those bolts, and it has not condemned it either.
What should you ask your surveyor?
- Where were the bolts relative to any damp-proof course you could see?
- Did you see staining on the house wall at the bolt line?
- Is the moisture path at the bolts unverified rather than confirmed?
What are the typical next steps?
- Treat the moisture path at the bolts as unverified.
- Note that no damp-proof course was visible in the dwarf wall.
- Ask a damp specialist to look at the junction if you need the path confirmed.
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 conservatory feels dry, has the bolt path been cleared?
No. A dry feeling on the day is not a view of the course or of the metal through the joint. The survey did not see a damp-proof course in the dwarf wall and did not open the bolts. The path stays unverified.
Does a lead flashing over the junction replace the missing course?
No. Flashing is a weather detail at the top of the junction. It is not a damp-proof course in the dwarf wall, and it does not show what the bolts are doing inside the joint. The survey has not treated flashing as that course.