When to test for radon
- when buying a new home
- before putting your house on the market
- before finishing the basement
- after major remodeling
- after near-by construction
- repeat radon tests every 1 to 2 years
Kinds of radon test kits
Radon levels fluctuate widely and depend on many factors like barometric pressure, wind speed, heating season. The short-term test kit is a snapshot over 3 to 7 days. EPA recommends two short-term radon test kits side by side, or a second test immediately after the first one using an identical radon test device in the same location.
The long-term alpha track detector provides a more reliable result by averaging the fluctuations in radon levels over 3 to 12 months.
If you have a private well, your drinking water may also release radon gas into indoor air in the shower, washing machine, or dishwasher. Test the radon level in your well water with the radon-in-water test kit.
Radon testing location
EPA recommends that you test in the lowest level of the home which is suitable for occupancy. But the buyer decides based on their expected use of the home – if they plan to finish the basement, it becomes the proper location for the test.
Some states and real estate practices require testing in the “lowest livable area” whether or not currently suitable for occupancy. This usually means radon testing in the basement.
Conducting the radon tests
Closed-building conditions are required for test measurements lasting less than 90 days to stabilize the concentrations of radon and radon decay products. Other than a furnace or permanently installed heat recovery ventilators, external-internal air exchange systems should not operate.
- Close windows and external doors at least 12 hours before beginning a short-term test.
- Record the start time and date on the packet and follow the testing instructions.
- Do not conduct short-term tests during severe weather (sudden changes in barometric pressure, severe storms, or periods of high winds).
- Place the test kit at least 20 inches above the floor in a location where it will not be disturbed. Most people hang up the test kit 3 to 5 ft. above the floor.
- Place the test kit away from drafts, high heat, high humidity, and exterior walls.
- Maintain closed-house conditions but operate the heating and cooling systems normally during the test.
- Once you have finished the test, reseal the packet, record the stop time and date, and mail it immediately to the lab for analysis.
Repeating the radon test
Select a procedure that best suits your goals. If you detect a significant radon level, repeat the test. If the radon level is above the EPA’s “Consider Action” limit of 2 pCi/L, you should proceed with radon mitigation. You can seal any cracks or openings and deep-seal the concrete with RadonSeal Penetrating Concrete Sealer.
If you plan to sell the house and your short-term radon test comes out anywhere close to the EPA’s Action Level of 4 pCi/L, reduce the radon level! Otherwise, the buyer’s test may show 4.1 pCi/L and your closing may evaporate.