After installation
A radon system is the only home repair with a built-in pass mark. Until the verification test exists, you own equipment rather than a result.
The filing half matters more than it seems: the folder you assemble now is what answers a buyer years from now without a second negotiation.
Before the installer leaves
Look at the manometer and note the reading — hard to reverse later
This is your baseline. A future reading only means something compared to this one.
Confirm the fan is running and note where it is mounted
It must be outside conditioned living space, and you need to know where it is.
Confirm the discharge is above the roofline and away from openable windows — hard to reverse later
A standard requirement and a common shortcut on a bargain job.
Walk the sealing work you can see
Floor-wall joint, penetrations, and the sump lid. What you cannot see, ask about.
Confirm any opened surfaces will be made good, and to what standard
Easier settled now than after the truck has gone.
The verification test
Confirm the system has run continuously for at least 24 hours before testing — hard to reverse later
Concentrations fall within a day or two of operation; testing sooner measures the transition.
Confirm the test is in the same location as the original measurement — hard to reverse later
Two numbers from two rooms cannot be compared.
Confirm closed-building conditions for the verification test — hard to reverse later
The same protocol as any short-term measurement.
Get the result on paper with the date and the credential on the same page — hard to reverse later
A verbal assurance is not a document you can hand a buyer.
If it comes back at or above the action level, invoke the remedy clause — hard to reverse later
This is unfinished scope, not a closed job.
File these four things together
The installer credential number as written on the contract — hard to reverse later
The first thing a buyer or inspector will want.
The written scope or system diagram showing suction-point locations
A future contractor servicing the system needs to know what is where.
The post-mitigation verification test report with its date — hard to reverse later
This is the document that turns a system into a documented repair.
The fan model and warranty terms, including who administers a claim
You will need this on the day the fan fails, which will not be convenient.
Set two habits
Glance at the manometer monthly — hard to reverse later
Level columns are the one unambiguous warning this system gives you.
Diarise a retest for two years out — hard to reverse later
The gauge reports pressure in the pipe. Only a measurement reports the air in the room.
What this checklist does not cover
A checklist that pretends to be complete is worse than one that states its edges. These are the things deliberately left out, each with somewhere better to go:
- This checklist covers the weeks after installation. Ongoing ownership is the annual inspection checklist.
- It does not cover troubleshooting a failed verification test in depth — the system health check tool and the retest-failed guide do that.
- It does not cover what any of this should cost.
Confidence and limits of this page
Every decision resource on this platform states its own boundaries. This is not a disclaimer — it is the part of this checklist you should read before relying on it.
- What we knowClaims on this page we stand behind, each traceable to an approved source or to observable structure.
- A post-mitigation verification test after at least 24 hours of continuous operation, in the same location and under closed-building conditions, is the standard way a system is confirmed.
- A manometer reports pressure in the pipe rather than concentration in the room, so it cannot substitute for a measurement.
- Fans must be mounted outside conditioned, occupied space, and discharge above the roofline away from openable windows.
- What we do not knowQuestions you may reasonably have that this page does not answer.
- Whether the sealing work you cannot see was done. Behind finished walls, you are relying on the contractor and on the verification result.
- How long your system will hold its result. Houses change, and that is what the retest habit is for.
- What research would settle itWhat it would actually take to answer the above — naming it is the difference between honesty and hedging.
- Longitudinal measurement of mitigated houses over five to ten years would establish how often results drift and what drives it. Published work on system durability is sparse relative to how many systems exist.
- A study of verification-test failure rates by scope completeness would tell homeowners how much the remedy clause is actually worth.
- What we do not claimClaims you might expect to find here and will not, with the reason.
- We do not claim a passing verification test means the house is permanently below the action level. That is what retesting is for.
- We do not claim a service life in years for any component.
- We do not claim any specific final reading is achievable — that belongs in the contractor’s scope, not here.
- What we cannot independently verifyFacts this page relies on that we could not confirm ourselves.
- Whether the work behind finished surfaces matches the scope. The verification result is the strongest available proxy and it is not a direct check.
Sources
- U.S. EPA — Radon
- U.S. EPA — Consumer’s Guide to Radon Reduction
- U.S. EPA — A Citizen’s Guide to Radon
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