Damp and moisture meters
A new patio has been laid above the damp-proof course line the surveyor pointed out. Why is that bridging a cause to investigate, not proof of rising damp?
Because a new patio has been laid above the damp-proof course the surveyor pointed out, the bridging is a cause to investigate and not proof of rising damp. A path that lets moisture cross the course can matter. It does not, by itself, show that moisture is rising inside the wall, or that an injected treatment is required. The survey records the patio against the line indicated. It does not diagnose rising damp from the paving, and it does not design a damp-proof treatment.
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 damp-proof course is bypassed if paving, render or ground connects the wall above it to the ground below. A patio laid high can do that, which is the bridge. Rising damp inside is a separate claim and needs its own evidence. High paving without that evidence is still a detailing fault. Call it bridging. Do not call it a proved case of rising damp in the plaster merely because the slabs sit above the line that was pointed out.
Confirm the course, the patio level and whether the wall above is actually damp. Lowering the paving, or separating it from the wall, is the sort of step that answers a bridge. A quotation for injection does not answer a high patio. Ask the contractor to deal with the levels and to say what internal evidence, if any, they are using. The report has not handed them proof of rising damp.
What should you ask your surveyor?
- Where does the patio rise above the damp-proof course the surveyor showed you?
- Did you see internal damp linked to this bridge, or only the two levels outside?
- Are you diagnosing rising damp, or recording bridging that should be investigated?
What are the typical next steps?
- Treat the high patio as a bridge to investigate, not as proved rising damp.
- Ask for the outside level to be dealt with before any injection is quoted.
- Keep any internal damp that is not in this note out of the patio sentence.
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 patio above the damp-proof course prove rising damp is present?
No. Bridging is a cause to investigate. The level of the patio does not, by itself, prove moisture is rising in the wall.
Has the survey designed a new patio or an injected damp course?
No. It records the bridge. It does not design the repair, and it does not treat the paving as proof of rising damp inside.