How to test your home for radon, step by step

Short-term or long-term?

• Short-term tests run from 2 to 90 days. Most are 2–4 days. They’re the quick way to find out whether you have a problem, and the usual choice for a home sale.
• Long-term tests run more than 90 days. Radon rises and falls with weather and season, so a long-term test gives a better picture of your year-round average.

Step by step

1. Close up the house. For a short-term test, keep windows and outside doors closed (except normal coming and going) for 12 hours before and for the whole test. Don’t run fans that bring in outside air.
2. Pick the spot. Use the lowest level you live in, like a finished basement, bedroom or family room. Avoid kitchens, bathrooms, laundry rooms and crawl spaces.
3. Place the device. At least 20 inches off the floor, away from exterior walls, drafts, vents, windows and direct sunlight. Leave it undisturbed.
4. Record the times. Write down exactly when the test started and stopped. The lab needs it.
5. Send it off fast. Mail it to the lab the day the test ends so the result is valid.

What to do with your result

• Short-term result of 4 pCi/L or higher: test again to confirm, with a long-term test or a second short-term test. If the average is 4 or more, fix the home.
• 2 to 4 pCi/L: the EPA recommends considering mitigation.
• Below 2 pCi/L: retest every couple of years, and after major renovations, a new HVAC system or finishing a basement.

Buying or selling a home?

Real estate deals need results fast and a test nobody can question. A certified professional test follows EPA and NRPP protocols, uses certified lab analysis, and comes with a written report. We offer expedited turnaround for real estate transactions.

Source: EPA, A Citizen’s Guide to Radon.