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When to Have Radon Testing Done in Your Home

When to Have Radon Testing Done in Your Home

Do you know enough about radon? You may be aware that it’s an odorless, colorless, tasteless gas that can contribute to developing lung cancer if it’s found in your home – if so, that’s a good start! Did you also know that you need to have radon testing done in your home to be sure it doesn’t have unsafe radon levels?

Here are the times it's most important to have your home tested for radon:

  • When You Buy a Home
  • When You Sell a Home
  • Periodically Following the First Test
  • Any Time of Year

Let's look more closely at the timing when it comes to radon testing.

When You Buy a Home

One of the easiest decisions to make should be testing a home that you’re planning to buy. This is a time when you want to check out as many things as possible about the home – you don’t want to get stuck with a house that has major problems you could have avoided.

Where you might hesitate is when the seller provides you with test results before you can ask for a test. You still may want to ask for a new test under some circumstances. The EPA provides a radon testing checklist that you can obtain, and if any part of that checklist wasn’t followed, you should have a new test done.

You should also test again if the test is more than two years old or if the current owner has renovated or made alterations to the home since the test was performed. One more reason to ask for a new test is if you plan to live on a lower level of the house (for example, a finished basement) that isn’t being lived in currently.

When You Sell a Home

Getting a radon test before you sell a home might not sound as attractive as getting one done before you buy a house – and of course, the person who buys your home is well within their rights to want a current test.

In the long run, a radon test can only help you sell the home. If the test shows safe levels of radon, you won’t have to worry about it and neither will your buyer. If the test shows unsafe levels of radon, then you may have to have radon mitigation done before you can sell it, but having the mitigation done won’t dissuade buyers – they’ll be relieved the problem is taken care of already.

Periodically Following the First Test

Maybe you’re neither buying nor selling a home, just living in it. How often do you need to test for radon? If you haven’t tested in years or don’t know when the last test was, now is a good time. There are two types of radon tests available – one that tests over the course of about 24 hours, and one that tests over several months. The longer test will be the one that provides you with more detailed and accurate results.

If the test shows unsafe levels of radon, you need professional radon mitigation services. DIY radon mitigation is not effective. A radon mitigation service can help with ongoing testing requirements. If your home tests as having safe levels of radon, it’s a good idea to continue to test every 2 years to ensure it's still safe.

Any Time of Year

Traditionally, radon testing was most accurate in the winter, because that was the time of year when homes were least ventilated due to people staying inside out of the cold. In many cases, it’s still recommended that people do their testing in the wintertime, and if you often leave doors and windows open during warmer weather, that may be true for you.

However, a study shared by Evict Radon demonstrates that radon levels are becoming more even across seasons. This may be because the increased use of air conditioning means that houses are no longer as ventilated in any season, allowing radon levels to build up in the house year-round. Therefore, it’s not necessarily important to test in a particular season any longer.


Plan on testing for radon before buying or selling a home. You should also do so if you know the house hasn’t been tested in years or don’t know when it was last tested. Following a test that shows acceptable radon levels, continue to test every few years. While many people have been told that winter is the best time of year to test, seasonality is becoming less important and testing can be done at any time of year.