Radon
A radon membrane, where it laps a service pipe in a void, looks torn. What continuity of that barrier was not proved, and what radon level was not measured?
The continuity of the radon membrane at that pipe was not proved, and no radon level was measured. The membrane looks torn where it laps a service pipe in a void, which is a visual break in the lap, not a test of the whole barrier and not a reading of the air. The survey has recorded the tear it could see. It has not proved the membrane is continuous around the pipe, has not traced the barrier under the floor, and has not measured a radon level in the house. A torn lap is not a number.
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 radon membrane is a sheet meant to separate the ground from the rooms. At a service pipe the sheet has to lap and seal. A tear at that lap is a gap in the thing you can see. It does not tell you how far the damage runs, whether other pipes are sealed, or what the indoor level is. UKradon publishes map information and discusses action levels as a separate subject. This inspection did not carry out a measurement, and it should not be read as one.
Tell the solicitor the membrane looked torn at a pipe in a void and that no level was measured. If a measurement is wanted, that is a radon test, not a sentence to add to the survey. If the lap needs repair, a specialist who understands these barriers should see it. Do not invent a level the visit did not take, and do not treat the tear as proof the rest of the floor is protected or unprotected.
What should you ask your surveyor?
- Where is the tear relative to the service pipe and the lap?
- How much of the membrane in the void could you actually see?
- Are you recording that no radon level was measured?
What are the typical next steps?
- Treat continuity of the membrane at the pipe as unproved.
- Do not invent a radon level the survey did not measure.
- Arrange a proper radon test if a level is what you need.
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 rest of the visible sheet looks intact, is the barrier proved?
No. An intact stretch does not prove the lap at the pipe, and the lap is where it looks torn. The survey has not traced the membrane under the whole floor. Continuity at that service pipe was not proved, and no level was measured.
Can a map of the area replace the missing measurement?
No. A published map is a different product. It does not measure this house, and it does not repair a torn lap. The survey recorded a tear and did not measure a radon level. The map does not fill that gap.