The Purpose of Radon Rocks in Building Foundations

When constructing a new building, one of the biggest things to think about is the foundation. The foundation provides a level surface for the building, protection from forces like earthquakes and floods, and increased stability overall. However, a proper foundation with a layer of radon rocks also provides protection from the natural radon gas in the earth. Let’s take a closer look at this crucial material and why it’s necessary to include a layer beneath every foundation.

What are Radon Rocks?

Radon rocks are made specifically for the construction industry and is typically a mix of rocks 10-30mm in size. It can also be called under slab rock because it’s most often used for the underside of basement floors in new home construction. It can also be used in other underground projects such as decks and parking lots. Since the rocks are natural, they can vary in colour from batch to batch.

Radon rock acquired its name because it is used to aerate radon gas away from the building as uranium in soil and rock breaks down over time. Since it is a permeable rock, it can be very effective in reducing or eliminating radon gas in buildings, as well as preventing the settling of radon gas in basements and concrete floors.

Radon rock is a mix of rocks 10-30mm in size.
Radon rock is a mix of rocks 10mm to 30mm in size.

Why Worry About Radon Gas?

Radon gas is a common concern because long-term exposure is the second leading cause of lung cancer among smokers and the leading cause among non-smokers.

Radon is a radioactive gas formed by the breakdown of uranium, a natural material found in all types of rocks and soils. As the gas breaks down, it forms particles that can become embedded in your lung tissue and release radioactive energy, damaging your cells. Once your lung cells are damaged, there is a chance of cancer developing.

Not everyone exposed to radon will end up with lung cancer and it takes a lot of exposure to radon to become a problem. However, it’s still important to be mindful of when working on brand new construction projects. Planning the foundation ahead of time makes all the difference to those using the building in the future.

Radon gas may enter house through cracks in foundation.
Radon gas may enter the house through cracks in foundation if not built properly.

Follow Safety Standards

In order to comply with the radon code, it is industry standard across Canada to have four inches of radon rocks beneath the concrete slab in the building foundation. This porous layer ensures that gas can easily be pulled away from the slab and building.

As you prepare for your next construction project, we can help you figure out how much radon rocks you need for a proper foundation. If you have any more questions about rock filler or want to bring in an expert team, get in touch with us anytime.

Scroll to Top