The test was run in a kitchen, bathroom, or laundry room
“The kit went in the downstairs bathroom because that seemed like the lowest level.”
Protocol excludes these rooms because humidity and mechanical ventilation both move readings, and in different directions. A bathroom extractor pulls air out; a laundry adds moisture that affects some device types.
The result describes a room with unusual air behaviour. It is real data about that room and a poor proxy for the rest of the floor.
Why this matters
What it changes about the decision in front of you.
- Extract ventilation changes the pressure relationship between that room and the space around it, which is the mechanism the whole subject turns on.
- Some passive device types are affected by sustained high humidity, so the reading may reflect the room conditions as much as the soil gas.
What it could influence
Where the effect is likely to show, and in which direction where that is knowable.
- The reading could sit above or below a living-area measurement on the same floor, and which way is not predictable from the description.
- A short test in a frequently used bathroom will be affected more than one in a rarely used cloakroom.
What this does not settle
What still stands. Noticing a problem is not the same as losing the evidence.
- The device functioned and produced a number. What is in question is what the number represents, not whether it happened.
- It does not establish that the house is fine or that the house is not fine; it establishes that this particular room was not the right place to ask.
- A second test elsewhere on the same floor is a small cost against a result that already told you the question is live.
What a professional is likely to ask
Worth having answers ready. None of these is a test you can fail.
- Whether an extractor fan ran during the test, and whether it is on a timer or a switch.
- What the room is used for and how often, which changes how much the conditions varied.
- Whether a living area on the same level was available for placement.
What you can check yourself
Things you can establish today, without anyone visiting.
- Whether the room has mechanical extraction, and whether it runs automatically.
- What else is on that level that would meet placement guidance.
What genuinely needs somebody on site
Where this platform stops. These are not questions a website can answer about your house.
- How that room ventilates relative to the rest of the floor, which is a pressure question rather than a visible one.
Categories a next step could fall into
Unordered, and none of them is a recommendation. Which applies depends on things this page does not know about your situation.
Related reading
- How testing works — Devices, placement, closed-building conditions, and what invalidates a result.
- False positives — Most disputed results are not false — they are invalid, mismeasured, or comparing two different things.
Sources
- U.S. EPA — A Citizen’s Guide to Radon
When you are ready to talk to somebody
Tell us about your home and what you are trying to work out. We will tell you honestly whether we can route it to a provider in your area today.