What Happens During a Professional Radon Test?

One of the most common reasons Michigan homeowners put off radon testing is simply not knowing what the process involves. There is a natural hesitation around inviting a professional into your home for something unfamiliar — what will they need access to, how disruptive will it be, how long does it take, and what happens with the results? The answers are more straightforward than most people expect, and walking through the process from start to finish tends to dissolve most of the uncertainty that causes people to delay.

Before the Test: Scheduling and Preparation

The process begins with scheduling, which for a professional radon test is typically straightforward. You will identify the lowest livable level of your home — usually a basement, whether finished or unfinished — as the primary testing location, since that is where radon concentrations are highest and where the most meaningful measurement can be taken. If your home has multiple levels that are regularly occupied, your technician may recommend testing more than one area.

Before the test device is placed, your home needs to be brought into closed-house conditions. As we covered in our post on short-term versus long-term testing, this means keeping all windows and exterior doors closed — except for brief, normal entry and exit — for at least 12 hours before the test begins. If your test is being conducted as part of a real estate transaction, your agent will typically coordinate the closed-house period with all parties involved.

It is worth noting what closed-house conditions do not mean. You do not need to leave your home. You do not need to turn off your HVAC system — in fact, running your heating or cooling system normally is appropriate and expected. Normal daily activity continues as usual throughout the testing period. The restriction applies to windows and exterior doors, not to how you live in your home during the test.

Placing the Test Device

When your technician arrives, the first order of business is placing the test device in the correct location. Professional radon tests use either electret ion chamber detectors or charcoal canisters, both of which are passive devices — they sit in your home and collect data without requiring power or any active operation on your part.

Placement follows specific protocols. The device goes in the lowest livable area of the home, at least 20 inches above the floor, away from exterior walls, and away from drafts, high humidity areas, and direct sunlight. It should not be placed in a kitchen, bathroom, laundry room, or any space with unusually high air movement. The goal is to measure the radon concentration in the air where people actually spend time, under conditions that reflect normal home use.

Your technician will identify the right location based on the layout of your home and document the placement details. The entire device placement process takes only a few minutes.

During the Test Period

Once the device is in place, your role is essentially to live normally while maintaining closed-house conditions. The test device does its work passively — there is nothing to monitor, nothing to check, and nothing to adjust. Most short-term professional tests run for a minimum of 48 hours, with many running 48 to 96 hours to capture a more representative sample.

During this period your technician may check in to confirm conditions are being maintained, particularly if the test is being conducted for a real estate transaction where the result carries contractual significance. Otherwise the test period is largely uneventful from the homeowner's perspective.

A few things to keep in mind during testing. Avoid running exhaust fans continuously — kitchen and bathroom exhaust fans used briefly during normal cooking or showering are fine, but running a whole-house fan or leaving exhaust fans running for extended periods can artificially lower radon readings. Avoid using a fireplace or wood-burning stove during the test period, as these can affect air pressure dynamics in the home. And maintain the closed-house conditions consistently — opening windows on a warm afternoon partway through the test period compromises the validity of the result.

Retrieving the Device and Laboratory Analysis

When the test period is complete, your technician returns to retrieve the device. This visit is typically brief — the device is collected, the retrieval time is documented, and the chain of custody is maintained for laboratory submission. For charcoal canister tests, the canister is sealed and shipped to a certified laboratory for analysis. For electret ion chamber devices, readings may be taken on-site or the device may be sent for processing depending on the specific equipment used.

Laboratory turnaround times vary but typically run between a few days and a week for standard submissions. Expedited processing is available in time-sensitive situations such as real estate transactions with tight closing timelines.

Receiving and Understanding Your Results

Your results come back as a pCi/L number — the radon concentration measured in your home's air during the test period. Your technician or testing company will provide the laboratory report and walk you through what the number means and what the recommended next steps are based on that result.

If your result comes back below 2 pCi/L, your home is in good shape. Periodic retesting every couple of years is a reasonable practice to make sure levels remain stable over time.

If your result falls between 2 and 4 pCi/L, a follow-up conversation about whether mitigation makes sense for your household is worthwhile. As we discussed in our post on understanding pCi/L levels, this range warrants consideration rather than either immediate alarm or dismissal.

If your result is at or above 4 pCi/L, mitigation is the recommended course of action. Your technician can discuss what that process involves and what you can expect in terms of timeline, cost, and outcomes.

Why Professional Testing Produces Better Results

A professional test differs from a mail-in DIY kit in ways that matter. Certified professionals follow established placement and chain-of-custody protocols that ensure the result reflects actual conditions in your home accurately. The laboratory analysis is conducted by accredited facilities. And perhaps most importantly, you have someone to call when the results come back — someone who can interpret the number, answer your questions, and help you decide on next steps with confidence rather than navigating it alone.

The test itself is the easy part. What matters is that it gets done correctly, with results you can trust and act on.

At All Michigan Mitigation, we conduct professional radon testing throughout West Michigan with the care and precision the process deserves. If you are ready to find out where your home stands, we are ready to help.

Visit us at allmichiganmitigation.com to schedule your test or reach out with any questions about what to expect.

All Michigan Mitigation is a West Michigan radon testing and mitigation company dedicated exclusively to helping homeowners understand and eliminate radon risk in their homes.