Radon In Basement: What Causes It and How to Solve it

Radon gas is all around us, all the time. Usually, it’s in such small concentrations that it’s relatively harmless. However, this radioactive gas can end up trapped in our homes and rise to levels which can threaten our health. The most common place where radon levels rise in the home is in the basement. But what causes this gas to build up there and once we find radon in basement, what do we do about it?

Understanding Radon

Radon is a radioactive element that naturally occurs around us as a gas. It’s released as trace amounts of uranium found in rocks and soil decays. Some areas are more prone to it than others but small amounts are usually present wherever you are.

Unfortunately for us, radon in basements is a common occurrence, thanks to their position being dug into the earth under your home. As basements are usually amongst the least well-ventilated spaces in our homes, the level of radon can build up here, seeping into the rest of our homes.

Entry Points for Radon

Ultimately radon gets into our basements from the surrounding soil but the exact entry point may vary from home to home. Some likely candidates include:

  • Bare earth floors
  • Vents
  • Cracks in walls and slab flooring
  • Unsealed joints
  • Porous cinderblocks
  • Sump pump hatches
  • Drains

Basically, any gap is a potential entry route for radon gas in your basement.

Health Risks

As we’re constantly surrounded by a low level of radon gas, released from the rocks and soil around us, you might be wondering what the issue is. Unfortunately, the risks associated with long-term exposure to high concentrations are pretty serious.

When radon builds up in an enclosed space like a basement it’s not immediately toxic- you won’t choke and splutter and gasp for air as soon as you’re exposed to it. Over the long-haul however, radon is linked to a greatly increased risk of lung cancer, particularly in smokers and ex-smokers, but also in non-smokers too.

Thanks to the fact that it isn’t immediately poisonous, once you’ve detected radon in your basement, you have some time to act.

Detecting Radon In Your Basement

The first step towards dealing with high levels of radon in your basement or elsewhere in your home is simple: detection. As radon gas is odorless and colorless, this will require specialised equipment.

Radon detection kits come in various types:

Short term tests

Short term tests, which you can either process at home or send off to the lab for more detailed results, are simple to administer. They work by taking samples over the course of between 3 and 90 days and offer a good indication of when there may be a problem and are a good place to start.

Longer term tests

Much like the short-term tests, these work by taking a continuous sample. Where they differ is in the length of time they cover- anything from 90 days to a whole year. This allows for a much more detailed view of your risks of long-term exposure.

Interpretation Of Radon Results

Your test kit should give you a result in a measurement called Picocuries Per Liter (pCi/L). This offers you a scale to judge the level of the radon problem in your basement.

A score of less than 2.7 pCi/L means that your exposure is low enough that you don’t have to worry about adverse health effects. You should test again every few years, but for the moment, you can breathe easy.

2.7-5.4 pCi/L would be considered an intermediate risk—this represents a statistical increase in the likelihood of cancer developing if you are chronically exposed over the course of a lifetime. If your household has young kids or teens, someone who works from home, or a family history of cancer, it may be worth taking steps to mitigate.

Anything above 5.4 pCi/L would be considered a high level of risk and should be mitigated to reduce the risk of your family developing health problems.

Solutions To Radon In Basements

Once you’ve determined that your exposure risk is worthy of taking action, what are your options for reducing the level of radon in your basement?

Sealing Cracks

As radon is naturally produced by the rocks and soil around your basement, blocking up entry points is a good start. Reducing the number of places where the gas can find its way in will drastically reduce your basement radon levels.

Not only will sealing cracks, holes and permeable surfaces like cinderblocks help to keep radon out in the first place, it can also offer great boosts in terms of waterproofing and improving the structural integrity of your home too. Another great bonus is the opportunity it gives you to turn your basement into a liveable space.

Mitigation Systems

A radon mitigation system could take a variety of forms and which is best will depend on the structure of your home and the concentrations of radon gas that you’re facing:

Active Soil Depressurization (ASD)

This is the most commonly recommended and effective method for reducing radon in homes with basements or slab-on-grade foundations. It involves installing a system of pipes and a fan to draw radon from beneath the foundation and vent it outside, above the roofline, where it disperses harmlessly into the air.

Passive Radon Systems

Similar to ASD but without the use of a fan, passive radon systems rely on natural air currents and pressure differentials to draw radon up from the soil and out of the home through a vent stack. These are often installed during new construction and can be later upgraded to active systems by adding a fan if radon levels are not adequately reduced.

Radon Sump Pump (Sump Pit)

This method is used particularly in homes with a crawlspace or a basement with a sump pump already installed. A cover is sealed over the sump, and a vent pipe with a fan is installed to draw the radon from under the cover and vent it to the outside.

In general, improving ventilation in your basement will offer the gas an escape route and avoid it building up over time to dangerous levels. On top of this, ventilation will allow air from outside to circulate more freely, diluting the gas which remains.

Professional Radon Mitigation

When dealing with a long-term problem, especially one which has the potential to threaten your family’s health, it’s always best to consult a professional. Bringing in an expert will mean that you have the advice needed to make an informed decision.

A professional will look at your test results, examine the space, weigh up the pros and cons of each option and make recommendations based on their findings. If you have any questions, they should be happy to answer them, fully explaining their thinking and putting your mind at rest.

As with any work on your home, it’s important that you are confident that you’re dealing with someone who really knows what they’re doing. Check out reviews and ask them about their certifications to ensure that you’re dealing with the best.

What To Expect During Mitigation

First, a professional will visit your home and inspect your basement to assess which of the various mitigation solutions will be most effective in terms of cost and result. They’ll want to take a look at any cracks, vents or other entry points, so make sure that your space is relatively clear.

Next, they’ll formulate a plan and present it to you along with a quote for the work. This is a great opportunity to ask any questions and put worries to rest.

The next stages will depend on the scope of the work. If opting for simply sealing up the cracks and vents or to increase ventilation by installing a system, work may progress relatively quickly and with minimal disruption.

If you’ve decided that a radon sump is more appropriate, you can expect work to take a little longer and be more disruptive as holes and trenches will need to be dug and pipes laid to install the system. Likewise a roof vent will require scaffolding, pipes and a higher level of disruption.

On Going Maintenance

Whichever mitigation system you opt to go for, it’s a good idea to schedule regular inspections to ensure that it remains in perfect working order for as long as possible.

As radon can be produced by rocks and soil at different rates under different conditions, once a problem has been identified, it’s a good idea to keep an eye on it with semi-regular tests to ensure that any mitigation work is still effective.

While having radioactive gas in your basement may seem like something from a sci-fi novel, it is in fact a very real problem that millions of us face. Luckily, you have time to consider your choices and act before it becomes dangerous.