Anyone with expertise mitigating radon gas?

[Corbet]

I just ran a test for Radon and it came back high. We remodeled a basement bathroom and I’m pretty sure this is the source. This bathroom was not part of the original home build AFAIK. There is a hole cut in the basement floor foundation for a bathtub drain. I could just fill this with concrete but then if we ever need to service the plumbing it’s a new nightmare. Any suggestions to seal this up in a manner that could be removed if needed?

Terrible picture for viewing pleasure. At least I have some access.

 

[Corbet]

My two current leading options are spray foam to seal the hole. This would be a pretty easy install. That crap is pretty much impossible to completely remove in the future but cutting out enough to service the plumbing should not be to much hassle. If this does not work I've got a real mess.

Option two. Pour a thin layer of concrete. Thin enough that you cold break it up with a hammer and remove if required in the future.

Any other ideas?

 

[Capriblue45]

You will want a vapor barrier, I would Sikaflex down a piece of heavy plastic and top off with a piece of sheetrock to protect the plastic.

 

[zgfiredude]

I hate to be "that guy" however my wife has lung cancer that has come back and long story short, we have a pretty good feeling that it stems from the high levels (unmitigated) of radon in her childhood home that we ended up back in to care for her aging parents for several years.

If you have levels high enough to be concerned with, please consider getting it mitigated with proper ventilation.

 

[Crash]

@Corbet what were the readings? I just tested my basement and the results were a 6 with anything over 4 being of concern.

 

[Crash]

Results are impacted by radon gases coming in basement windows and settling to the floor as they are heavier than the atmosphere.

 

[Corbet]

@Corbet what were the readings? I just tested my basement and the results were a 6 with anything over 4 being of concern.

first night was 8.4
I should note its a walk out basement.

 

[Corbet]

You will want a vapor barrier, I would Sikaflex down a piece of heavy plastic and top off with a piece of sheetrock to protect the plastic.

Please expand on how you'd address the bather drain plumbing and the fact I can't really get good access under the bath tub.

 

[Corbet]

I hate to be "that guy" however my wife has lung cancer that has come back and long story short, we have a pretty good feeling that it stems from the high levels (unmitigated) of radon in her childhood home that we ended up back in to care for her aging parents for several years.

If you have levels high enough to be concerned with, please consider getting it mitigated with proper ventilation.

This is my mindset. Looking to solve this myself if I can before calling in a pro. If I find a solution that significantly drops my readings I can wait until summer to have a vent system installed.

 

[MDH33]

Hey Corbet, radon is really common here in Iowa. When I moved here I checked and it was high. It's not as easy as just sealing it off. I used a mitigation company and they drilled a bunch of test holes in the basement slab and tested the flow under the slab to determine where to install the air pump(s) I had good flow so only needed 1 pump, which pulls the gas from below the slab and pushes it out above the roof. My whole system was under 2k installed.

For your bathroom, they would probably just need a vapor barrier below that plumbing and then a radon pump could be installed further away.

 

[Hulk]

We had a thick plastic barrier installed in the entire crawl space plus a pump that pulls air from below the slab. We test for radon multiple times per year.

 

[Corbet]

Problem I have is that this is a finished basement with carpet and title floors. Drilling test holes is highly undesirable.

When we bought the house in 2008 we had it tested as part of the home inspection. It failed and the sellers did some mitigation which included sealing this exact hole with 5e old bath tub. They also had a vent installed on one side, no blower. It then passed inspection but with what level I no longer recall. I never retested until now as we reopened the hole. At this point I do wish I had more data.

 

[DaveInDenver]

We had a thick plastic barrier installed in the entire crawl space plus a pump that pulls air from below the slab. We test for radon multiple times per year.

That's how it was mitigated in the previous house. A crawlspace seal and vent. In the first house with a full basement they did something else that didn't not require the heavy white plastic seal but that was also 30 years ago and might have been a completely sham.

It's important to realize it's not "solved" per se. Radon is ubiquitous and naturally occurring. So you can only continually reduce it's concentration where you spend time.

This is my mindset. Looking to solve this myself if I can before calling in a pro. If I find a solution that significantly drops my readings I can wait until summer to have a vent system installed.

It's not something that's a simple slap-dash DIY thing.

You have to depressurize the soil gases from under and around the house, ideally before it's built so the persistent flow is negative away from the foundation or the inside is positive to prevent it entering.

If that's not possible then you have to completely seal inside and exchange the air. The problem is if you don't get a good seal the venting fan might make it worse by creating negative pressure that pulls radon in from the soil. Think of a water bed, all it takes is a pin hole and the whole envelope is compromised.

The radon companies have techniques they can use. It's worth getting some quotes. Not all of them are reputable, though, so get a few opinions.

You might be able to do some or even all of it yourself but you just need to understand your soil, your building envelope and what's going to be the most effective way to do it.

 

[nakman]

We have the typical PVC tube coming out of the basement slab, with a fan sucking air out constantly. Made the sellers put it in 18 years ago... I should probably test for Radon more often..

anyone know where the makeup air comes from? I often wonder how much of a vacuum that poor little fan outside is working against. I have already replaced it once, when it started making a bunch of extra noise. Is there a way to introduce fresh makeup air? Or does that defeat the purpose here

 

[Inukshuk]

Mitigate, Mitigate, Mitigate.
Disclose, Disclose, Disclose.
(presented as information only, not to be taken as legal advice, always consult a lawyer)

@Crash - I am very surprised to hear that. Our area is generally lower due to the high clay soils. My house is super leaky (= good for ventilation, bad for heating bills) and pressurized with the swamp cooler all summer but now maybe I should test for having new windows a couple years ago. When I did a home test a few years ago it was well below the 4 limit.

 

[Inukshuk]

We have the typical PVC tube coming out of the basement slab, with a fan sucking air out constantly. Made the sellers put it in 18 years ago... I should probably test for Radon more often..

anyone know where the makeup air comes from? I often wonder how much of a vacuum that poor little fan outside is working against. I have already replaced it once, when it started making a bunch of extra noise. Is there a way to introduce fresh makeup air? Or does that defeat the purpose here

It gets enough through natural leakiness that would be present in a home the age of yours.

 

[Hulk]

Karie's good friend and co-leader of their girl scout troop died a few years ago from lung cancer. Never smoked a day in her life. Her family blamed it on the radon in their house. That was when we got serious about testing and having all the mitigation equipment installed. A few thousand bucks to prevent my family from cancer seemed like a very good deal.

Bonus: sealing the crawl space with a thick plastic liner had the unintended benefit of making our crawl space far less miserable to crawl into.

 

[Crash]

Mitigate, Mitigate, Mitigate.
Disclose, Disclose, Disclose.
(presented as information only, not to be taken as legal advice, always consult a lawyer)

@Crash - I am very surprised to hear that. Our area is generally lower due to the high clay soils. My house is super leaky (= good for ventilation, bad for heating bills) and pressurized with the swamp cooler all summer but now maybe I should test for having new windows a couple years ago. When I did a home test a few years ago it was well below the 4 limit.

With a reading of 6 and the recommended limit of 4, I’m not too concerned. Just had a chest cat scan and I’m clean. We’ve lived here 31 years and I spend an inordinate amount of time in the basement. That is where the stereo is and I listen to it probably 20 hours a week.

 

[KC Masterpiece]

Curious what a high level is. We have 2 fan systems in our basement. One was dead when we purchased and we had it replaced. Our report had an average reading of 1.8 pCi/l in the basement / garden level.

 

[DanInDenver]

I’ve been down the rabbit hole for the last month.
Readings need to be done over an extended period of time (3months min) at the lowest level where you spend the most time.
Winter readings trend higher than summer, but weather such as rain will also cause a spike.
Consumer meters to consider would be Airthings Corentium, or EcoQube.

https://www.reddit.com/r/radon/s/MrkAECPDV9

Canadian government testing of consumer Radon detector/meter

Consumer-Grade Electronic Radon Monitors – CNRPP