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Can Radon Mitigation Cause Foundation Problems?

Can Radon Mitigation Cause Foundation Problems?

Radon is a chemical that seeps into your home from the soil beneath and can be harmful after reaching a certain level. It sounds terrifying, but fear not! You can add a radon mitigation system to combat that problem. However, since you have to cut into your foundation, you may be worrying about foundation issues caused by installing a system.

Do radon mitigation systems cause foundational problems? Well, the short answer is there is no direct evidence pointing to a radon mitigation system causing issues. To best allay these fears, you need to:

  • Learn what causes foundation problems
  • How radon mitigation systems are added to existing homes
  • In what ways might the system affect your foundation
  • Learn how to fix foundational problems

Kick back and breathe easy as we explore more information on the above topic.

Causes of Foundation Problems

Foundation issues can result in structural damage to your home. While minor shifts in your home’s foundation may not be a problem, continued shifting can create cracks in walls and cause doors and windows to not open or close correctly. There are several ways the foundation can become damaged, moisture being the leading cause, according to

When there is heavy rain, snow, or a plumbing leak, the ground swells. The swelling pushes against the foundation. However, suppose a home is built when the ground is already saturated. In that case, there is a risk of the soil beneath the home shrinking during a drought. The shrinking causes the structure to settle.

While moisture, either excessive or drought level, is the leading reason for the foundation to buckle, it is not the sole reason. Sometimes the soil is not adequately prepared before laying the concrete slab. If it's not compacted correctly, the home may settle quickly and damage the structure.

Adding Radon Mitigation Systems to Existing Homes

Some areas in the United States now recommend that a radon mitigation system be installed during construction. But what of older homes? Rest assured that a professional can install a mitigation system if needed even though the home’s foundation is already in place.

According to This Old House, a professional installer will need to cut into the foundation in homes with no crawl spaces. The hole in the concrete needs to be large enough to hold a 3-inch PVC tube. That is only the beginning of removing radon from your home.

After cutting the foundation, they will need to dig out a pit below the slab. A large hole is necessary for dense soil as a fan must pull gasses from the ground and ventilate them into the air. However, if your home has a layer of gravel beneath the concrete, a smaller hole is optimal.

The ventilation pipe is installed from the hole to the attic. Once in place, the bottom of the tube goes into the pit. Then the installer "seals the joint using hydraulic cement." Before venting to the outside, the pipe goes through an in-line fan. This fan runs round the clock to help draw the gasses out of the pit. Once through the fan, the line "exits" the roof. Next, your installer will use a "standard plumbing boot" to seal around the ventilation pipe and prevent roof leaks.

How a Radon Mitigation System Can Affect Your Foundation

Suppose your home does not have a crawlspace. In that case, chances are the installer will have to cut through your concrete foundation. The most significant danger to your home’s foundation is indeed water. But cutting into it can compromise your house’s foundation.

According to Saniflo, whenever you cut into concrete, you decrease the foundation’s structural integrity and the structure on top of it. The floor is not as solid as it used to be, nor is the soil underneath. Once it is disturbed, the house may begin to "settle differently," causing further damage.

No matter how experienced the professional is, there is never such a thing as a perfect cut. Despite your best efforts, the edges of the cut will begin to crumble, with minor fractures spreading away from the hole. Creating cuts in concrete is unpredictable at best. Unless the radon mitigation system is installed during construction, there is no way for the installer to know if the concrete is reinforced with "rebar." There is also no way to know if there are rocks in the soil below.

Once the slab is broken, you may find additional leaks or water seeping in from the ground below. If left in disrepair, you may find that you’re not only battling higher levels of radon than you expected but also mold and mildew from the moisture.

Fixing Foundation After Radon Mitigation System Installation

Even if there are no structural issues caused by the cracks in your foundation, you need to seal them as soon as possible. This is because radon can seep into your home through the small gaps.

If the cracks in the concrete slab are causing foundation issues, you need more than some epoxy to fix it. Typically, when foundation repairs are necessary due to settling, it is accomplished by using piers. The piers go deep into the bedrock below your home to stabilize the slab.


While there is no direct evidence that installing a radon mitigation system will damage your home’s foundation, issues may arise during the installation process. Foundation problems usually come from increased or decreased moisture. The excavating of the soil could cause destabilization in the foundation. Rest assured, foundation problems are expected in some regions of the country. There are methods to fix any issues without damaging your radon mitigation system.