Testing vs. mitigation: which step are you on?
Money spent in the wrong order buys anxiety instead of answers. This page sorts the two steps — measurement and mitigation — into the order that fits your actual situation, including when skipping straight to quotes is the rational move.
The one-question sort
Do you have a trustworthy number? A test conducted under closed-house conditions — windows shut, normal HVAC, device placed in the lowest lived-in level — is trustworthy. A transaction test performed by an Illinois-licensed measurement professional is trustworthy by construction. If you have that number, you are past testing; act on it. If you don’t, testing is your next dollar, not mitigation.
Test types, compared honestly
| Method | Duration | Strengths | Limits |
|---|---|---|---|
| Short-term kit (charcoal) | 2–7 days | Cheap, fast, fine for a first look | A snapshot — radon swings day to day |
| Continuous monitor (CRM) | 48+ hours | Hourly data, tamper-aware; the transaction standard when run by licensed pros | Costs more; still a short window |
| Long-term test (alpha track) | 3–12 months | Averages across seasons — the truest picture of exposure | Slow; useless inside a deal window |
When a retest earns its delay
- One short-term result between 2 and 8 pCi/L, with no deadline: confirm, then decide from the average.
- Suspect conditions (windows open, test near a draft, device disturbed): redo it properly.
- Staying long-term at 2–4: a long-term test gives the average that band deserves.
When a retest wastes your window
- Licensed CRM result inside a transaction: the clock is running; quotes are the productive next call.
- Results well above 8: confirmation almost never changes the decision.
- Serial retesting in search of a lower number: that’s shopping for comfort, not measuring a house.
And after mitigation: testing returns
The sequence ends where it began — with measurement. A post-mitigation test verifies the system actually lowered your number, and a retest every couple of years (EPA’s standing guidance) confirms it keeps doing so. Mitigation without verification is a fan and a hope. See how systems work and what the numbers mean.
Common questions
Can I go straight to mitigation without any test?
You can — some owners installing during a renovation, or buying a home where every neighbor mitigated, choose to — but you’d be fixing an unmeasured problem, and you’ll still need testing afterward to verify performance. The economical order is almost always: cheap test, informed decision, verified fix. A contractor who discourages pre-testing is selling hardware, not outcomes.
Why did winter and summer tests on my house disagree?
Seasonal physics. Closed-house winter conditions concentrate radon; open-window shoulder seasons dilute it. Both tests measured truly — they measured different operating modes of your home. For action decisions, weight the closed-house result or run a long-term test; you live in winter mode for a large share of the year here.
Are the $15 hardware-store kits accurate enough to trust?
For screening, yes — properly used charcoal kits from reputable labs are how millions of homes get their first number. Their weakness is protocol sensitivity: placement, duration, and closed-house discipline are on you. Treat a clean kit result below 2 as reassuring, anything elevated as a prompt for a confirming test or quotes, and any sloppy deployment as void.
The seller offers “their” old test result. Is that my number?
It’s information, not diligence. Conditions, seasons, and even the house itself (renovations, HVAC changes) may have shifted since. Illinois requires sellers to disclose known results, which is why you have it — but buyers ordering their own licensed measurement during inspection remains the standard, and no serious agent will advise skipping it to save a modest fee.
Sources
- U.S. EPA — A Citizen’s Guide to Radon
- U.S. EPA — Home Buyer’s and Seller’s Guide to Radon
- IEMA-OHS — Illinois Emergency Management Agency and Office of Homeland Security — Radon Program
- Illinois General Assembly — Radon Industry Licensing Act (420 ILCS 44)
Already holding an elevated result?
Then you’re on the mitigation step — get free quotes from independent licensed contractors and decide with real numbers.