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What is a Radon Mitigation System?

What is a Radon Mitigation System?

Written By: Jake Gilbertson, Lead Radon Mitigator

Est. Reading Time: 5 minutes


With 2 in 5 homes in Minnesota having high Radon levels where mitigation is recommended, you probably have heard about Radon Mitigation Systems before, but you may not feel confident that you know what they are and what they actually do. 

Radon Measurement and Mitigation is regulated by State licensing and the National Radon Proficiency Program certification. The training is thorough and quite technical, and the health risks of concentrated Radon exposure can be serious, but that doesn’t mean that there needs to be mystery shrouding the process and what to expect if you need to have a Radon Mitigation System installed in your home.

At Marigold Home Inspections, we are dedicated to open and clear communication with our clients and Realtor Partners. It’s important to us to make sure we provide information about our industry and services we provide in a way that isn’t full of technical jargon, but that anyone can use to better understand their homes and maintain their safety.

Testing for Radon and installing a Radon Mitigation System if Radon levels come back high is a very important part of keeping your home safe, so we’ve compiled some of the questions we get asked most about Radon and Radon Mitigation Systems!

What is Radon?

Radon is a naturally occurring radioactive gas that is a byproduct of uranium and radium breaking down in the earth’s soil. As uranium and radium decay, they release the gas known as Radon into the earth’s atmosphere. Since Radon is a radioactive gas, it poses health concerns to humans when we are exposed to concentrated levels. As Radon enters the body it decays into heavy radioactive metals that break down and permanently damage cell tissue. Long term exposure to concentrated levels of Radon is the second leading cause of lung cancer.

PicoCuries per liter is the unit of measurement for Radon gas and the average estimated outdoor levels are around 0.4 pCi/L. The average estimated indoor levels of homes in the US is 1.3 pCi/L. In Minnesota, 2 in 5 homes have high levels of Radon where mitigation is recommended.

How do you know if your home has Radon?

Radon gas is 100% undetectable by human senses and the only way to know what your Radon levels are in your home is to have a test completed. We wrote a blog post about Radon Testing, so hop on over to that real quick if you’d like more info! 

Marigold can complete a Radon test for your home as a part of your real estate transaction or as a stand alone service. We use some of the most advanced industry technology to test your home over a 48 hour period and deliver a detailed report of the results.

My home has high Radon, now what?

The Environmental Protection Agency (EPA) recommends having your home mitigated if indoor Radon levels are 4.0 pCi/L or higher.
Mitigation should be considered when levels are between 2.0 – 4.0 pCi/L.

You will need to contact a licensed Radon Mitigation Professional to install the mitigation system. It is important to note that there are licenses for both Radon Testing and Radon Mitigation, so be sure the company you choose is licensed to install a mitigation system. Also, as with most things, a commitment to continual learning is important as State requirements are continually changing and you want to be sure your Mitigation Professional is up to date with current regulations.

The cost of a Radon Mitigation System can range from $1,800 to several thousand dollars. There are many factors that play into how a system must be built to be effective, so best practices say that a site visit is recommended in order to most accurately assess and quote a mitigation system that will be custom built for your home.

Now it’s time for the question we’ve been leading up to:

What is a Radon Mitigation System?

It can be helpful to understand how Radon enters the home in order to understand how a Radon Mitigation System works. Homes have what is called a “stack effect”, where the structure acts like a straw due to hot air rising, pulling air from the ground around the house up through the home. There are various pathways that air, and Radon with it, can enter the foundation of your home, such as cracks, foundation and wall seams, or sump pump baskets. Since Radon is continually breaking down in the soil, the gasses are drawn into the home with the air, and being sucked up through the “straw”, creating concentrated levels of Radon in our homes.

Installation of a mitigation system starts with visually inspecting and then sealing all the pathways where air is being sucked into the home. This prevents the continual intrusion of Radon gas into the home, so that the current levels can be dealt with, and a system can be created to vent additional gas away from the home. If your home has a sump pump, a special cap is constructed and fitted to ensure a seal is created but access is maintained.

The next step is to choose a location to install the system that is as minimally intrusive in your space as possible, but allows for the system to function properly. We then drill a hole through the slab foundation and install a pipe system that vents the Radon from under your home to above the roof line. The vent system can either exit your home from the basement and travel up the outside of your home to the roofline, or it can travel up through the inside of your home, using accessible attic space to vent through the roof.

A continuous fan is installed in the system that creates consistent suction within the system. This draws Radon out from beneath the home, and pushes it through the vent system and out above the roofline, and helps maintain low levels of Radon in your home post-mitigation.

What happens after installation?

A follow-up Radon Test is required to ensure the Radon levels have been brought down to safe levels. Marigold guarantees that levels come in lower than 2.0 pCi/L, but our levels are often much lower. 

After the test confirms the system is working properly and Radon levels have been reduced to healthy levels, it is then recommended to retest for Radon every 2-5 years.

At Marigold, we guarantee our workmanship for life, and materials are guaranteed for 5 years.

Wrapping Up

The purpose of a Radon Mitigation System installed in the home is to continually draw the Radon out from beneath your home and vent it outside above your roof.
These custom systems are designed specifically for your home and it’s important to choose a company to install your system that is properly licensed, current on regulations and requirements, and will stand by their work and be there if you ever need them in the future.