Vacant Houses Don't Have More Radon

As a Minnesota home inspector who does a lot of radon testing, I hear a lot of myths about radon being repeated over and over again.  I’ve actually heard other home inspectors perpetuate a few of these radon myths as well.

Myth: vacant houses have high levels of radon. The idea behind this myth is that radon will build up in a house while it’s sitting vacant, so a radon test on a vacant house won’t be accurate.  This simply isn’t true.  Radon has a very short half-life; as radon particles die off, they’re replaced with new ones.  A radon test conducted on a vacant house will be just as accurate as a test conducted at an occupied home, all things being equal.

Myth: radon is mostly found in older houses. In reality, the radon doesn’t care how old the house is.  Both new and old houses can have radon problems; we have found zero correlation between radon levels and the age of the home.

The one bit of unintentional truth to this myth is that starting in June of 2009, Minnesota began requiring passive radon mitigation systems in all new construction homes.  We’ve performed many radon tests on these new homes, and have yet to find a single new construction house with a high radon level.

Myth: opening the second story windows shouldn’t affect the radon test, because the test is located in the basement. The problem with this myth is that houses act like chimneys.  Opening the windows on the second floor might actually increase the radon levels in the home.  For a valid test, the windows in the house need to be kept closed.

Myth: radon tests should always be placed in the lowest level of the home. If the home has a crawl space or a basement that nobody will be spending any time in, why in the world would you want to know what the radon level is down there?  If you’re testing your own home, put the test in the lowest level of the home that you use regularly.  For a real estate transaction, the radon test should be placed in the lowest level of the home that could be used regularly.

Myth: radon tests aren’t needed for homes with walkout basements. While we’ve found that radon levels in homes with walkout basements tend to generally be lower, this is certainly no guarantee that the radon levels will be low.  The highest radon level we’ve found at a home with a walkout basement was nearly four times higher than the EPA action level.

Myth: granite countertops have an effect on radon levels in a home. This myth gained popularity in 2008 because of a media scare.  You don’t need to worry about granite countertops.  They’re fine.  You can read more about this myth here – radon in granite.

Myth: you need to hire a professional to test for radon. The do-it-yourself radon test kits that you buy online or at a home improvement store will work just fine.  It takes a little longer to get the results, but these kits are far less expensive than hiring a professional to test your home for radon.

Myth: holy water will keep radon from entering a home. Ok, I made that last one up.  That concludes my list of the most common myths about radon.

Reuben Saltzman, Structure Tech Home Inspections - Email- Home Inspector Minneapolis

    

This Radon Test Is Useless

While doing a Truth-In-Sale of Housing re-inspection, I noticed a radon monitor present in the crawl space.  This home didn't have a basement, just a trap door that led to a 5' x 5' crawl space with a water heater, water meter, and gas meter.

 

My first thought:

Huh, someone is doing a radon test.  Great!  Must have sold the house.

My next thought:

What the heck is that test doing in a crawl space?

Radon will enter a home through the basement or crawl space floors and walls, so the lower areas in a house will always have the highest concentrations of radon.  This particular home had an uncovered crawl space, which is typically a good indicator that the radon test will come out high.

In this particular case, the radon test was completely useless.

The EPA protocol for radon testing during a real estate transaction requires the test to be placed in the lowest level of the home that could be used regularly.  In other words, where someone might actually spend some time.

A crawl space is the place in the home where someone would be least likely to use regularly, if at all.  If someone regularly spends time in their crawl space,  they have bigger problems than radon to worry about.   Even if the radon level for this particular test is very high, the numbers are meaningless.  The test needs to be done in the living area to be of any use.

Another requirement for radon tests is that the seller maintain closed-house conditions for 12 hours prior to the test and throughout the duration of the test, which means keeping the windows and doors closed, except for normal traffic.  When I arrived at this house, most of the windows were wide open, and the owner didn't have any idea that his windows were supposed to be closed.  The owner should have been notified about the radon test a day ahead of time, and the inspector should have left a form at the house for the owner to fill out, stating that the EPA protocols for testing would be adhered to.

There is no licensing requirement for radon testing in Minnesota, but seeing a test performed like this makes me think there should be.

Reuben Saltzman, Structure Tech Home Inspections - Email - Detailed Home Inspection Reports