Damp and moisture meters
A damp-proof membrane on a refurbished wall stops above the solid floor. What path does that gap leave for moisture at the junction?
The damp-proof membrane that stops above the solid floor leaves a gap at the junction, and that gap is a path for moisture past the edge of the lining. The refurbished wall may look covered over most of its height while the strip down at the floor is not. The gap is a reason to investigate. It is not, on its own, proof of rising damp, and a meter on the new finish above it is only an aid.
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 membrane only protects the wall where it is actually continuous. Stopping short of the floor leaves the junction dependent on whatever sits under the finish, which this visit may not have seen. Moisture at that edge can mark a skirting without the whole wall being wet. The survey can record where the membrane ends. It cannot see through the solid floor.
Do not stretch the comment into a claim that the whole wall is rising damp, and do not ignore the gap because the upper wall looks newly lined. The unfinished edge is the finding. Closing it would be a later specification, not a result the survey has already demonstrated. Keep the path described as a gap, and investigate that gap.
What should you ask your surveyor?
- Where does the membrane stop, relative to the solid floor and the skirting?
- Could you see the junction itself, or only the edge of the membrane above it?
- Are you describing a gap in the lining, rather than diagnosing rising damp?
What are the typical next steps?
- Record the membrane as stopping above the solid floor.
- Do not call the refurbished wall protected while that junction stays open.
- Investigate the gap before you accept a claim that the lining is complete.
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 wall above the membrane is dry, is the floor junction dry as well?
Not on this finding. A dry upper wall is not the gap. Moisture can still pass the unfinished edge where the membrane stops.
Does the membrane prove the damp has been cured?
No. It shows a lining was applied and that the lining stops short of the floor. It does not prove a cause, and it does not prove rising damp.