Damp and moisture meters
What has a home survey actually proved about a wet-room floor it could not flood-test?
Very little about whether the floor holds water. A wet-room floor depends on tanking, falls and the outlet, and a home survey does not flood-test it. Dry feet on the day are not a test. Stains on the ceiling below, if any were visible, are the clue the visit could actually use.
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 wet room has no tray. The floor itself is supposed to be waterproof and to drain to an outlet. The tanking is hidden under the finish. A surveyor can see the fall if it is obvious, a stained outlet, silicone failures, and any tell-tale on the ceiling of the room below. They cannot see the membrane, and they will not dam the room and fill it. An ordinary shower taken by the occupier is not a test the surveyor witnessed unless they say they did, and they usually should not be running the fittings as a trial.
Concealed parts are not guaranteed. If the ceiling below is dry and unseen voids stay unseen, the report should limit itself rather than pass the wet room. If that ceiling is stained, the floor above is a proper suspect and still has not been flood-tested. Do not read a tidy finish as a certificate. Ask when the wet room was put in and whether any guarantee exists, then treat the paper as a seller question. The absence of paper is not proof it leaks. The absence of a flood test is why the survey cannot clear it.
What should you ask your surveyor?
- Did you see a stain on the ceiling under this wet room?
- What could you see of the falls and the outlet, as against the hidden tanking?
- Are you leaving the waterproofing as not tested?
What are the typical next steps?
- Do not read a dry visit as a flood test of a wet-room floor.
- Look at the ceiling below before you decide the floor is sound.
- Ask for any guarantee as a paper trail. It is not a substitute for what the survey could not test.
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
Is a shower tray easier to judge?
Slightly, because the joint is visible. It is still not flood-tested on a normal survey.
Does a linear drain that looks clean prove the tanking?
No. A clear grate is a grate. The membrane is under the floor.