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Radon Testing

How Often Should My Home Be Tested?

The EPA recommends that you get your home tested for radon at least every other year. Some people may choose to get tested more often for peace of mind. (This is perfectly fine!)

Radon411 offers accurate short-term and long-term testing by a certified and skilled Radon Technician. Why should you use a Certified Technician? All of our Certified Radon Technicians are professionally trained to maintain the highest industry standards and deliver accurate testing results.

Short Term Tests – Potential Radon Exposure

Often, at the time of sale, it is desirable to know a building's potential for radon exposure, independent of how the building is currently used. Short-term tests are typically conducted over a two or three day period. Results of short-term tests represent the radon potential of the home, rather than the actual exposure encountered under normal living conditions unless residents keep the home's windows and doors closed year-round. That's because EPA guidelines for short-term radon tests require "Closed-House Conditions," to promote maximum radon concentration during the brief test period.

The placement of the device within the home must follow the manufacturer's instructions and is dependent on whether or not the test is being conducted for a real estate transaction.

Short-term tests are usually 2 to 7 days long and are done under "closed-house" conditions that begin at least 12 hours before the test and remain in effect for the duration of the test.

If a short-term radon test is conducted correctly for a minimum of two days, under closed-house conditions, one can reasonably say:

  • If the result is less than 4.0 pCi/L, the annual average of the home under normal lived-in conditions is also likely to be less than 4.0 pCi/L.
  • If the level is at or above 4.0 pCi/L, the house has the potential to average more than 4.0 pCi/L, and you should consider follow-up testing or taking action to reduce (mitigate) the radon in the home.

Long-Term Tests – Actual Radon Exposure

For the occupants of a home, actual radon exposure depends on how they use the home, where in the home the occupants spend their time, and how much freshair is brought into the living area. Since these factors may vary over time, the only reliable way of measuring the actual radon exposure is to conduct a long-term test for at least three months, under normal living conditions.

In the past, prospective homeowners have often been reluctant to purchase a home before performing a long-term test, for fear of not being able to correct a radon problem afterward. However, improved technology and the proven durability of radon mitigation systems have served to reduce much of that concern.

This does not mean that a short-term test is less valuable as part of a home inspection process; but rather, if the results of that test show a potential radon concern, a long-term test can more accurately show actual average radon levels. By conducting a long-term test after moving into a home, the homeowner can control test conditions and, if needed, make decisions on how a mitigation system will be installed.

The placement of the test device within the home must be in accordance with the manufacturer's instructions.

Testing Process

Radon 411 conducts an affordable, professional short-term radon test that meets the EPA’s standards of radon testing Located in the Kansas City, MO metro, The testing device, a continuous radon monitor (CRM), is a calibrated instrument that will be placed in the lowest level of the home or building suitable for occupancy. Radon testing requires a minimum 48 hour test period with 12 (hours) of "closed-house conditions" prior to conducting the test. The continuous radon monitor (CRM) will take hourly readings for the duration of the test. Upon retrieval of the testing device, hourly readings are included in a detailed radon report specific to the structure tested.

Prepare for Testing

For reliable test results, follow this testing checklist carefully. Improper testing may yield inaccurate results and require another test. Disturbing or interfering with the test devices or with closed-house conditions may invalidate the test results and is illegal in some states. If the following items cannot be confirmed, another test must be taken:

  • Notify the occupants of the importance of proper testing conditions. Give them a copy of this guide if possible and explain the directions carefully.
  • Conduct the radon test for a minimum of 48 hours.
  • Maintain closed-house conditions (keeping doors and windows closed) for a minimum of 12 hours before the 48-hour test begins and throughout the duration of the test.
  • If the house has an active radon-reduction system, make sure the vent fan is operating properly. If the fan is not operating properly, have it (or ask to have it) repaired and then test.
  • Operate heating and cooling systems normally during the test. For tests lasting less than one week, operate only air-conditioning units which re-circulate interior air.
  • Do not disturb the test devices at any time during the test.

Upon completion of the radon inspection is done the raw data will be downloaded and provided to you in a report with hour by hour measurements giving you an overall and EPA average.

Call 816-844-0977 to schedule your inspection today.

Radon Testing Tips

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
  • Every 1 to 2 years

Radon levels fluctuate

  • Radon levels fluctuate widely and depend on many factors like barometric pressure, wind speed, heating season. The short-term test is a snapshot of over 3 or 4 days. The long-term alpha track detector averages the fluctuations over 3 to 12 months.
  • 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.
  • Since radon levels fluctuate, a short-term test is just a snapshot. Some argue that short-term tests are worthless. Find out more at short-term vs long-terms radon test kits and what a homeowner should do.

Closed House Conditions

Placing the test device in a closed room or leaving doors and windows open during the test is improper and can invalidate a test.

Short-term, "closed house" radon tests should not be conducted during rainy weather, especially when the rain is accompanied by persistent winds. Changes in barometric pressure and other forces can cause indoor radon levels to rise during a rain storm and skew the test results higher than found under otherwise normal conditions.

The following protocols should be followed to comply with the requirement for "closed-house" conditions:

  • Exterior windows and doors are kept shut, except for normal entrance and exit.
  • Fans and blowers which move air from the outside of the house to the inside, or exhaust inside air to the outside, are turned off, including swamp coolers
  • Whole house fans should be off
  • Air conditioners should be put on "recycle" or "max.-cool," but not on the "fresh air" setting
  • Combustion or makeup air to gas fired appliances are NOT to be closed
  • The house can be occupied during testing, provided the "closed house" conditions described above are maintained.
  • If testing during warm weather, keep the air-conditioning on and set the fan to recycle indoor air. Don't use the "fresh air" setting. Evaporative coolers, sometimes called "swamp coolers", should be turned off during the test, to avoid bringing outdoor air into the house

Test Device Location

The location of a radon test depends upon whether the test is being done for a real estate transaction or not. Since the purpose of the first, short-term test is to be able to identify homes that are clearly below 4.0 pCi/L, it is necessary to place the test device in a part of the home that would be expected to have the highest radon level.

The device should be placed in a room that is frequently occupied, but where high humidity in the air would not be expected. Examples of good locations would be bedrooms, dining rooms, and family rooms. Never place the device in a closet, crawl-space, storage area, kitchen, garage or bathroom.

In order to have confidence in the radon reading, the device should be placed in the lowest occupied space, for non-real estate transactions. A finished basement is normally chosen in those parts of the country that typically have basements.

In the case of a real estate transaction, the device should be placed in the lowest portion of the house that could be finished and occupied by future occupants.

If the radon measured is below 4.0 pCi/L, there is a good reason to believe that the rest of the home is also below 4.0 pCi/L. Furthermore, if the closed-house test protocols are followed, there is a good reason to believe that a low short-term test result (below 4.0 pCi/L) means that the average radon throughout the year will probably also be below 4.0 pCi/L, during normal use of the house.

Remember, short-term tests determine the radon potential of a home, independent of how future homeowners may operate or occupy the house.

The 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.

Test Device Placement

Radon 411 uses the newest radon measuring equipment on the market, but even so, strict protocols must be followed to ensure accuracy.

A proper location must be selected to obtain an accurate measurement of radon in air that represents the breathing space of the home. The test device should be at least 20 inches from the floor, 4 inches from another object, 12 inches from an exterior wall, and 3 feet from an outside window. The device can be placed near an interior wall, perhaps on a bookshelf, but should be at least four inches from the wall or the back of the shelf, to allow good air circulation.

Devices that are designed to be hung by a string should be approximately 12 inches from the ceiling.

Test devices should also be located away from drafts and should not be placed in rooms with excess humidity.

  • 3 feet from windows or exterior doors
  • At least 20 inches above floor
  • 4 inches from other objects
  • Where it won't be disturbed
  • Away from drafts
  • Out of direct sunlight
  • Not on hot or warm surfaces

Conducting the Test

Closed-house conditions are required for test measurements lasting less than 90 days in order to stabilize the concentrations of radon and radon decay products and increase the reproducibility of the measurement. Other than a furnace or permanently installed heat recovery ventilators, external-internal air exchange systems should not operate.

The following protocols should be followed to comply with the requirement for Closed-house conditions:

  • Exterior windows and doors are kept shut, except for normal entrance and exit.
  • Fans and blowers which move air from the outside of the house to the inside, or exhaust inside air to the outside, are turned off, including swamp coolers
  • Whole house fans should be off
  • Air conditioners should be put on "recycle" or "max.-cool," but not on the "fresh air" setting
  • Combustion or makeup air to gas-fired appliances are NOT to be closed
  • The house can be occupied during testing, provided the "closed house" conditions described above are maintained.
  • If testing during warm weather, keep the air-conditioning on and set the fan to recycle indoor air. Don't use the "fresh air" setting. Evaporative coolers, sometimes called "swamp coolers", should be turned off during the test, to avoid bringing outdoor air into the house
  • 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 significant radon and want to know exactly your radon level, repeat the test.

If you plan to sell the house and your short-term radon test comes out anywhere close to 4 pCi/L, reduce the radon level and re-test afterward. Otherwise, your closing is likely to evaporate by a radon reading of 4.1 pCi/L. What should be your safety margin? Because radon levels fluctuate widely, it depends on your judgment.

If you plan to live in the house, you are motivated to provide a safe home for your family. If your radon level is significant (above the US average of 1.25 pCi/L), work on reducing the radon level. For tips on sealing any openings and the concrete, check out RadonSeal radon mitigation. Re-test after the repairs

After Service is Complete, this device will be picked up by a Professional Educated Technician and data will be downloaded and analyzed to determine the current average in the home. Your report will be provided via email.

Test Results

If you perform the short-term test and the results are higher than 4.0 pCi/L, the EPA recommends you take further action. The next step should be to retest the home on a long term basis, ideally for a year, then decide if mitigation is necessary.

However, if the initial short-term test finds radon levels are significantly elevated, such as 10 pCi/L or more, you may want to repeat the short term test using a different test device to confirm the radon is still elevated. You can then average the two results and base your mitigation on the average.

The health risk from radon is cumulative, increasing over time if the radon level is elevated and not corrected. The health risks from radon occur over a long period of time and radon concentrations vary from season to season. An average radon level, measured over all four seasons, is a better indicator of actual health risk over time.

On the other hand, if your initial readings are significantly elevated, you should take action to quickly confirm these readings and then proceed to mitigate the home. Again, you may want to repeat the short-term test, using a different test device to confirm the radon is still elevated, then average the two results and base your mitigation on the average.