Radon emanation is when the radon source for a home or dwelling is not the soil but something else–often a building material. Read more below about this rare–but not unheard–of phenomenon.
Radon Sources
Radon is a naturally-occurring radioactive gas. It’s part of the uranium decay chain and begins as uranium in rock. Uranium is very plentiful on earth. Radon is the gaseous part of the decay chain, so it seeps up from underground and enters our home through all foundation types. Read more about how it decays and enters are homes in this in-depth article.
For the vast majority of homes, if you can remove air from under the home (a process known as active soil depressurization), then you stop the radon flow and make it safe for occupancy. However, what happens if the radon isn’t coming from the soil? Well, then you’ve got a big mess on your hands. Here’s how that can happen and how to fix it.
Radioactive Building Materials
Uranium is very common in bedrock. Granite in particular. Granite is also a very common countertop type. You may see where this is going. Granite counter tops are the most common source of radon emanation problems. Fireplaces are another. Pretty much any place in your home that has rock as part of a building material. I cringe every time I see a cool home built into a rock somewhere, as I’m certain the home owner and builder were blissfully unaware of the radon potential.
If the radioactive rocks are in the concrete itself, then you’ve got a real difficult problem home. Concrete plants should be testing for radioactive building materials, but that’s rarely a requirement. If it is, it’s not always enforced. Look to the home builder if you found radioactive building materials and seek out restitution, as you’ve got an expensive fix on your hands.
How to test for contamination
Hopefully, by this point you’ve found a qualified radon pro to help you. If not, call us and we’ll help you find the best one in your area.
The methodology for finding the contamination is relatively simple. You need to place a continuous radon monitor in direct contact with the suspected building material and limit airflow mixing. The most common way is taping a 5 gallon hardware store bucket on top of a counter top or fireplace (whatever you suspect is the source) and measuring the readings over a few hours or days.
If you haven’t located the source, consider using the pro-grade EcoTracker radon “sniffer”. This device helps you narrow down the room and sometimes can nail down the source to within a few square feet.
How to fix emanation
Once you’ve found the source, the best step is to remove the effected building material entirely. I’ve heard horror stories of mansions having to have hundreds of square feet of granite countertops removed and replaced. In the long run, this decision saves money and your health.
What if the radon is coming from your concrete itself? In that case, your only option is air replacement. As Bruce Sneed, world-renowned radon trainer, would say in these instances, “the solution to your indoor air pollution is dilution!” Air exchangers bring in fresh outdoor air in an energy efficient manner and exhaust “dirty” indoor air.
Read this full article on how air exchangers can reduce radon concentrations
Can this really happen?
Yes, this really happens. In 2015, an entire apartment building in Atlanta was shown to have been built with contaminated concrete. Radon is often found in rocks like granite. Concrete aggregate uses local rock quarries to fill the cement slurry and make strong building materials. What happens if that concrete aggregate has high uranium levels? Well the whole building could become unsafe.
Read how NRPP certified pro Matt Koch tackled this exact scenario here.
I’ve heard many anecdotes over the years from customers and at the International Radon Symposium. Emanation is surprisingly common. I even once found my wife’s rock collection from her college days to be contaminated. We immediately removed it from our home and I’m in the process of writing up another article on this experience.
Always ask your builder if they are certain their concrete is radon-free. Remember, you can build radon ready. Get your free takeoff here.
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