The middle Tennessee area is considered a high radon belt according to the EPA. There are several different types of radon monitoring equipment in the marketplace approved for real estate transactions. The most common are the charcoal canisters and the continuous monitoring equipment. Some home inspectors like to use the charcoal canisters for doing their radon testing. These are inexpensive costing about $10 each as compared to $1500-$4000 for a good grade of continuous monitoring equipment. I prefer to use the continuous monitoring equipment and here’s why:
- One cannot get instantaneous readings from the charcoal canisters. The charcoal canisters must be sent off to a laboratory to get the final results and generally, this can take from three to five days. In this fast paced real estate market waiting for the results of a radon test and sometimes but the home inspection contingency over the time limit.
- Another reason that I prefer to use the continuous monitor system is rain. Rain can drive radon out of the ground and depending upon the location of the property and how many inches of rain has been delivered by the storm, radon levels can get skewed. With a visual representation of elevated readings, a competent home inspector can determine if the rainfall has adversely affected the radon test. At that point the decision can be made to either retest the property or back the elevated readings out and recalculate the average for the property. You cannot do that with charcoal canisters.
- Another reason that I prefer the continuous monitor system is tampering. Sometimes the homeowner will take the radon monitor out of the house place it on the back porch and then put it back in the House today that the inspectors to return and retrieve the device. The devices that I use have anti-tampering that record time and temperature as well. If I notice any sudden temperature changes in the output of strongly suspect tampering and note that in my report. Once again, tempering cannot be detected with the charcoal canister system.
A good example of how rain will adversely affect a radon test will start with the red arrow and end with the blue arrow. During this time period, a cold front and rain had moved into the area causing the radon levels to rise in the property. This is quite normal to see. I have seen some storms drive the radon levels up past 100 pico-Curies per liter. However in this test the radon levels remained relatively low and really did not adversely affect the total outcome for this particular property.
I hope that this information is been helpful to the real estate community and shed little light on radon monitoring systems.
This posting and the contents written here are the intellectual property of Michael Thornton of Complete Home Inspections, Inc. providing home inspections for Brentwood, Nashville, Davidson and Williamson Counties of Middle Tennessee. The views and opinions expressed are just that - views and opinions of Michael Thornton and those who comment. This post is a contribution to the ActiveRain Real Estate Network.