Radon mitigation

I’m not sure if this community is the right place to discuss this, but there is a tech angle, so here goes nothing.

A few years back I bought an AirThings Wave. It was on sale at Best Buy, it was a bit nerdy and I knew radon was a potential issue for anyone, so I spent the $200Cdn. AirThings’ system was a bit clunky and junky, but over the years they have managed to improve it enough that I no longer have a lot to complain about. Unfortunately they’ve kind of obsoleted my device with their newer system, because it needs a “home hub” to provide Internet access, and it’s not compatible with my first gen system. (The first gen just used bluetooth and your phone.)

Anyway, it turned out that radon in my house was marginally high. I checked the government website, and they suggested it be mitigated, but as I wasn’t using the basement for anything but my nerd equipment and various other clutter, I didn’t investigate actually doing it. I assumed it was stupidly expensive. Having recently looked into it, it’s about $2500Cdn to have a professional do a mitigation.

Times have changed, people are working from home, some more space would be nice, and I would like to build (and have humans occupy) a room in my basement. So I need to do the mitigation.

So my point of this message is to ask some questions:

  • Have YOU checked your radon? Do you even know it could be an issue?
  • Do you have any experience with DIY-ing a mitigation? If so, please share any advice or cautions.

In my house I have a sump pit, so I have investigated using it as the “collection well” for the radon pump. This entails buying a purpose built lid to seal off the sump pit. I also have a rough in in the basement for a bathtub that I need to deal with (looking for advice on what to do… it’s open to the ground, and I don’t want to permanently disable it because one day I want a bathroom there.) There are significant hairline cracks in the floor that I will also probably need to address, and I don’t really know much about that process either (advice appreciated.)

One thing I don’t have a clue about, is that there are a number of deliberate holes in the floor. There is a floor drain direct into the sump pit, meant to handle a leak in the water heater. There is a pipe beside the furnace that is a drain for any moisture from it (from the A/C I presume.) There is another pipe/drain for the HRV. I presume I will have to close over the floor drain, and find some way to seal around the two pipes (spray foam maybe?)

Anyway… TL;DR: If you have advice about a DIY radon mitigation in a sump well, please share.

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I don’t have anything to add about DIY mitigation, other than I wouldn’t chance it. Most of the homes in our area need it, and if homes don’t have it, mitigation is usually put in when a home is sold. That’s how we got ours, we asked for a radon test that showed it was slightly elevated past the mitigation point, so the seller had to install one.

I don’t believe that mitigation was as common 30 years ago when my aunt purchased her home in this area. And the reason every time I see Radon mitigation I recommend people take it seriously is she passed away from lung cancer most likely due to radon exposure.

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Radon mitigation is usually only done when you buy/sell a house. As part of home inspection, a radon test is done, if the levels are too high, the buyer tells the seller to fix it. That’s what we did when we bought our home. It wasn’t even a surprise.

I have the same Airthings wave. As I am now using the basement, I installed the mitigation myself. Cut the number from 8 to 0.8 (2 year average). One caveat is that I have found the Airthings to get very flakey as the batteries wear out, the readings start to fluctuate significantly, so change them when you see the the numbers spike more than usual.

I have the same sump setup that you describe. I filled the floor cracks with urethane caulk, you do need to seal the slab as best as possible because you want to create negative pressure under the floor as well as keep the loss of heated air from your house down. Also the opening for the tub would need to be sealed. I also made sure the drains for the ac and humidifier have traps. Your floor drain should already have one.

In the sump, be sure the water level that turns the sump pump on and off allows the lines into the perimeter weeping tiles to always be dry so the suction pump can communicate with the perimeter system.

I used PVC pipe for the fan plumbing and sealed the sump with a piece of plywood with holes cut for the fan, ac drain, and sump pump outlet. I sealed the edges with duct tape. In my area, it costs about $10 a month to run the fan