Radon Testing and Home Inspection Process - American Radon Mitigation Considering waiving the home inspection? Here is what you need to know about Radon Testing

Radon Testing and Home Inspection Process

Considering Waiving the Home Inspection? What You Need to Know About Radon Testing

If you are buying a home, we highly recommend having a thorough home inspection conducted, including a radon test, to avoid any costly issues or repairs down the road. In addition, conducting a radon test can protect you and your family from potential health issues and provide peace of mind. Here is what you need to know about radon and radon testing when buying a home.

What is Radon?

Radon is a naturally occurring gas that comes from the natural breakdown of uranium in the rock and soil. It’s both radioactive and cancer-causing. Unfortunately, you can’t see, smell, or taste it. The amount of radon gas in the air is measured in picocuries per liter of air, or pCi/L.

Dangers of Radon and Why You Should Test

According to the Environmental Protection Agency (EPA), Radon gas decays into radioactive particles. These tiny particles can get trapped in your lungs when you breathe. As they break down, these particles release small bursts of energy that can damage the cells that line your lungs and lead to lung cancer.

According to the EPA, radon is the leading cause of lung cancer among non-smokers and the second-leading cause among smokers. Radon is also estimated to cause more than 20,000 deaths in the United States every year.

According to the Minnesota Department of Health, 2 out of every 5 homes tested in Minnesota contain Radon levels that pose significant health risks.

What to Look for if the Home Has an Existing Radon Reduction System


Check to ensure that natural draft combustion appliances (i.e., natural draft water heater) are not back-drafting and exposing your family to carbon monoxide.

First, close all the windows and turn on all appliances that exhaust air from the home (i.e., range hood, dryer, and bath fans).

Next, ensure the B-vent is cool to the touch (metal flue pipe above the water heater, the furnace may be tied into it). If it is not cool, turn the thermostat on the furnace down or wait for it to cool down.

Then, turn up the water heater dial or turn the hot water on until the water heater turns on.  Set a timer for 1 minute.

Finally, using a smoke pen, place it near the opening in the flue. Smoke should go up and out, not back toward you. You could also use a mirror if you do not have a smoke pen. A mirror will fog up if there is back-drafting. A lighter works as well. The flame will either be drawn up the flue or be blown out if it is back-drafting. 

Check out this video demonstration.

If your natural draft combustion appliance is back-drafting, try cleaning the fresh air intake screen (Click here for cleaning instructions) and repeat the test. You may need to replace the water heater with a power vented gas or an electric water heater if the issue is not resolved.

Fire Stop Collars

The common wall between your house and garage is a fire-rated wall. The ceiling of the garage is sometimes a fire-rated wall as well. If your radon system vent pipe penetrates this fire-rated wall, a fire stop collar should be installed on the pipe, not over the fitting.

In addition, an intumescent smoke sealant is required by some manufacturers behind the fire stop collar to prevent smoke from entering the house.

Finally, the fire stop collar should be screwed into a wood structure or secured using toggle bolts. This will ensure it functions properly in the event of a fire without falling off.

If any of these steps are missing, you should call a licensed radon mitigation professional.

Check out this video for more information

Roof Leaks

Make sure the pipe flashing is installed properly.  Check that the rubber seal around the pipe is not deteriorating from sun exposure. If there are any leaks, contact a professional roofer in your area.


The suction created by the radon fan draws the fluid up on one side of the gauge. You’ll notice that there is a small piece of clear tubing that goes from the top of the manometer to a small hole in the radon vent pipe. The other side of the manometer is left open. Think of it as if you are sucking on a straw. When you suck, you draw the fluid up the straw, and when you stop sucking, the liquid goes back down. The same is true here.

Are the Fluid Levels Different?

Radon Inspection fan running
U-tube fluid levels are different, indicating that your radon fan is running.

That’s good. Your radon fan is working! You want the oil in the manometer to be higher on one side and lower on the other.

Are the Fluid Levels Equal?

Radon Inspection fan not working
If the fluid levels in the U- tube are equal, your radon fan is not working.

This is not good; your radon fan is not operating.

If your U-tube is equal, check that the fan is plugged in and that the outlet is working properly, or contact a licensed radon professional in your area.

Radon Alarm

If a radon alarm is present, turn off the radon fan to test the alarm. The alarm will sound if it is working. 

If the alarm is not working, ensure it is plugged in, ensure GFCI is not tripped, and replace the battery if applicable.

Ensure Radon Fan is Wired Properly

For outside radon systems, ensure the fan is hard-wired with a disconnect (switch) outside. Corded plugs are not allowed outside.

If the system is inside, ensure the fan is not on an extension cord and is plugged directly into an outlet within 6 feet.

Outside radon systems are susceptible to freeze up in the winter. Therefore, you will be exposed to higher radon concentrations if this happens.

Sealing Cracks

Gaps and cracks in the concrete floor, floor to wall joints ( where the concrete floor meets foundation walls), and the top of the open block cores (with interior drain tile) should be sealed.

Sealing increases energy efficiency and helps reduce radon levels, and reduces the chance of back-drafting natural draft appliances. If this step is missing, sealants and expanding foam can be purchased for sealing at your local hardware store or online.

For more information on radon system standards, click here

Conduct a Radon Test

Whether the home you are buying has a radon system already installed or not, most importantly, a radon test should be conducted to ensure acceptable radon levels.  When it comes to testing, you have several options.

  • Short-term radon test kits: Short-term kits are by far the most widely used and cost-effective tests in the world. If you are testing radon in your home for the first time, you should start with an EPA-approved single-use, short-term test.
  • Long-term radon test kits: Long-term tests are the best way to determine your exposure to radon during different seasons and living conditions in your home. They are typically used after a short-term test returned radon levels between 2–3.9 pCi/L.
  • At-home digital radon monitors: These portable measuring instruments allow you to take accurate readings of radon concentrations daily, weekly, and long-term. They are primarily used when needing to test multiple rooms or locations.
  • Professional radon test: A licensed radon measurement professional will utilize radon testing devices calibrated annually and have ongoing checks throughout the year to ensure accuracy. Radon professionals can provide an accurate report, typically within three days.  A professional test is often required in real estate transactions.

Additional information on radon testing

Purchase radon test kits

Get an estimate on professional radon testing

Radon Test Results: What is a Safe Level of Radon?

There is no safe level of radon. The outdoor radon concentrations are typically between 0.2 and 0.7 pCi/L. As a result, a radon mitigation system will not be able to lower your radon levels below the levels found outside your home. On average, the family’s we help see radon levels of 0.4 pCi/L after having radon mitigation. 

The EPA strongly recommends homes with radon levels of 4.0 pCi/L or more have a radon mitigation system installed. We believe just getting your radon levels below 4 pCi/L is a horrible goal to shoot for. When two-thirds of radon-related lung cancer cases come from homes that test below 4, why is getting radon below 4 the goal of most radon mitigation companies? We think you deserve more protection, and that’s why our goal is and always will be to make your home as safe as possible. We believe we owe it to you.

Contact us for a free radon testing or mitigation estimate.