Do Earth Tubes Cause Radon Problems? Separating Myth from Mechanism

Posted on | Posted on Meadow Cern

Question 2 of 6 answered

There is a colourless and odourless gas that seeps up into some homes through cracks in the foundation, or even through pipes or tubes, etc., which can be dangerous to breathe over the long term. Many people wonder how it can be mitigated if you use earth tubes for cooling our home without air conditioning? So that is the question: Do earth tubes cause radon problems?

Radon comes up almost as often as mold does, and the two get lumped together a lot even though they are really separate issues with separate causes. I want to walk through the actual mechanism here, because once you understand why radon can become a problem, the fix is pretty straightforward.

What radon actually is

Radon is a naturally occurring gas that seeps up out of soil essentially everywhere, in amounts that vary a lot by region and geology. It is already a known factor in basements and crawl spaces, which is why radon testing kits exist in the first place. Earth tubes did not invent this gas. The question is whether a buried tube gives it an easier path into your house than it already has.

Where the risk actually comes from

A lot of older or budget earth tube builds use perforated drainage pipe, the same kind used for foundation footer drains, because it is cheap and easy to find. Those weep holes are great for letting excess moisture escape into the surrounding soil. They are also an open door for radon to seep in along the entire length of the pipe, not just at the ends.

If that tube is also sloped toward the house to help with drainage, you have built a pretty direct invitation for both water and radon to travel the same direction air already wants to move.

That combination, perforated pipe plus a slope toward the house, is really the whole mechanism. Remove either piece and the risk drops off fast.

How to design around it

● Use solid wall pipe, not perforated. If radon is a particular problem in your location, then solid (brand new) sewer pipe is already sealed along its length, so gas cannot enter except at the open ends.

● Slope the tube away 1-2 degrees from the house toward the outside intake, not toward the living space, so the direction water and gas naturally want to travel is away from your home.

● Seal every joint. Fewer joints is better here too, which is one more point in favor for the fusion of a straight run pipe compared to lots of glued or fitted angled sections.

● Keep the intake end far enough from the house and away from soil known for elevated radon in your area.

● Test your indoor air after the system is running, the same way you would test any home. It takes one kit and an afternoon, and it turns it from a guess into a known number.

None of this is about being scared of the ground. It is about understanding that any opening between soil and living space, whether that is a sump pit, a crawl space, or an earth tube, deserves the same basic precaution. Solid pipe, sealed joints, and a slope pointed the right direction handle the vast majority of the risk.

See more here

I cover pipe selection and slope orientation in more detail in the book, along with the radon testing approach I used on my own system before I trusted it. If you want the full breakdown, with diagrams, sizing information, and step by step installation, a full section about radon, and more, that is why I wrote Cool Your House Without AC: Free Air Conditioning for Life with Geothermal Cooling Earth Tubes. It is available now in paperback on Amazon and at Barnes & Noble.

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