Reuben Saltzman

This Radon Test Is Useless

 While doing a Truth-In-Sale of Housing re-inspection today, 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.

Trap DoorRadon Monitor In Crawl Space

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