Learn how to choose, place, complete, and interpret a home radon test, then use EPA and Virginia guidance to plan the right next step.
Radon testing at home is a small project with an important purpose: it tells you whether this invisible, odorless gas is building up indoors. You cannot judge radon by the age, condition, location, or appearance of a house. A test is the only reliable way to learn the radon level in a specific building.
This guide explains how to test for radon without turning a home-safety task into a source of panic. It covers choosing a test, selecting a location, following the test period, reading the result, and deciding what to do next. It does not replace the instructions supplied with a test kit or the advice of a qualified radon professional.
Radon comes from the natural breakdown of uranium in soil and rock. It can move through openings around foundations, joints, drains, utility penetrations, and other pathways. Any home may have an elevated level, including homes with basements, crawl spaces, or slab-on-grade foundations.
The Virginia Department of Health Indoor Radon Program says testing a home, workplace, or other regularly occupied space is the only way to know whether an indoor radon problem exists. A map can show general potential, but it cannot predict the result for one address.
A do-it-yourself kit can be a practical first test when you can follow the directions and keep the device undisturbed. The U.S. Environmental Protection Agency explains where to find a kit and how to locate a qualified provider in its radon test kit and professional directory.
Consider a qualified measurement professional when the property is part of a real-estate transaction, the building is large or complex, a previous result was elevated, you need documentation for a landlord or program, or you are not confident that the test conditions can be maintained. Virginia requires radon testers and mitigators working in the state to hold recognized certification; the VDH program links to current provider directories.
Before buying, confirm that the kit includes clear instructions, a laboratory fee or explanation of any additional fee, a use-by date, a return method, and contact information for questions.
Short-term tests provide an initial snapshot over the period stated by the manufacturer. Longer-term tests measure across a broader span of changing weather and household conditions. The right choice depends on why you are testing and how quickly you need information.
For a first screening, many households begin with a short-term kit and follow up according to the result and official guidance. If a deadline is not driving the decision, a longer test may provide a better picture of the home’s typical level. Do not combine instructions from different kits; use the timing, placement, and return process for the exact device you have.
Place the device in the lowest level of the home that people use or could use regularly, such as a finished basement, family room, bedroom, office, or play area. If the lowest level is unfinished and rarely occupied but might later become living space, official guidance or a radon professional can help you decide whether to test there as well.
Avoid kitchens, bathrooms, laundry areas, direct sunlight, fireplaces, exterior doors, open windows, fans, vents, and places with high heat or humidity unless the manufacturer specifically allows them. Keep the test away from the floor, exterior walls, and objects that could block normal air movement, using the distances in the kit instructions.
Choose a location where children, pets, visitors, cleaning routines, and daily activity will not move or cover the device.
Read the complete instructions before opening or activating the test. Some short-term tests require “closed-house” conditions before and during the test, while allowing normal entry and exit. Weather restrictions may also apply. Follow the kit rather than relying on a general checklist.
Write down:
This record is useful if the result is delayed, the laboratory asks a question, or you need to repeat the measurement.
Activate or open the device exactly as directed, then leave it in place for the required period. Do not put it in a cabinet, move it from room to room, or close it early because of concern about the possible result.
Maintain any required window and door conditions, but continue ordinary entry and exit. Do not create artificial conditions that do not reflect the instructions—for example, sealing the home in a way the kit does not request or running extra fans to influence the reading.
If the device is knocked over, covered, exposed to water, or left out too long, contact the manufacturer or laboratory before submitting it. A repeated test is more useful than treating an invalid result as certain.
At the stated end time, close or deactivate the device, complete every required field, and send it using the specified method. Delays can affect some tests. Save a photo or copy of the device number, form, tracking details, and submission date.
Results are commonly reported in picocuries per liter, written pCi/L. Keep the report with the location and timing notes so a later test can be compared accurately.
The EPA recommends fixing a home when the radon level is 4 pCi/L or higher and says people should consider fixing levels between 2 and 4 pCi/L. The agency explains that guidance on its radon action-level page.
An initial elevated result is not a reason to improvise a repair. Follow the report and official guidance about confirmation testing, then speak with a properly credentialed mitigation professional when appropriate. Mitigation plans should be based on the building, foundation, result, and current standards. Do not assume that opening windows, using an air cleaner, sealing one crack, or placing a fan in a basement is an adequate radon-reduction system.
If the result is below the EPA action level, keep the record and consider retesting after major renovations, foundation work, changes in ventilation or occupancy, or according to current federal and state guidance.
If you rent, ask the property owner or manager whether the building has been tested, what area was measured, when it was tested, and whether any system is installed. Put requests and results in writing. Do not alter the building or install equipment without authorization.
Multifamily buildings require planning because one unit’s result may not describe every ground-contact space. Property managers, housing organizations, schools, and community groups should use guidance written for their building type and avoid presenting one measurement as proof for an entire complex.
A community radon effort can help residents understand where to find kits, how to use them, what assistance is available, and how to locate qualified professionals. Materials should use plain language, large readable type, captions for video, multiple formats, and a contact method that does not require internet access.
UWP’s Wellness Education and Resources pages support clear, practical learning. For related healthy-home planning, see the Journal guide to improving indoor air quality.
Choose a suitable DIY kit or qualified professional, place the device in the lowest regularly used level, maintain the required conditions, complete the full test period, and return or read the device exactly as directed.
Use the lowest level that people occupy regularly or could occupy regularly. Avoid kitchens, bathrooms, laundry areas, drafts, direct sunlight, heat, high humidity, and locations where the device may be disturbed.
It depends on the device. Short-term and long-term tests use different measurement periods. Follow the dates and hours printed for the specific kit rather than using a general estimate.
Costs vary by kit, laboratory fee, shipping, location, and professional service. Check what the price includes, and consult the current Virginia radon program because public test-kit offers can change.
Retesting may be appropriate after renovations, foundation work, occupancy or ventilation changes, installation of a mitigation system, or when current official guidance recommends it. Keep prior reports for comparison.
EPA recommends fixing a home at 4 pCi/L or higher and considering action between 2 and 4 pCi/L. Follow current EPA and state guidance and use a credentialed professional for mitigation planning.
Do not treat a portable air cleaner as a substitute for a radon mitigation system. Radon reduction requires a building-specific approach based on the measurement and current professional standards.
This article provides general health and home-safety education, not individualized medical advice or licensed radon testing or mitigation advice.