[hlg]

We're in the process of building a new house in Eastern Tennessee. The state of TN and the county in which we are building has a higher occurrence of radon gas than many other areas in the US -at least according to the US EPA.

Our build is still at the foundation stage and we expect framing to begin soon.

I'm leaning toward getting a certified radon contractor to install a mitigation system in the crawlspace; where a constantly running fan creates positive airflow to help vent radon gas from beneath the home.

Anyone here have any experience or expertise in this area? If so, I'd appreciate thoughts and advice.

Thanks-

 

[fixitagain]

Yea get a reputable professional to handle it. I thought the newest tech was to encapsulate the crawlspace and keep the air conditioned.

 

[OneIsNone]

We're in the process of building a new house in Eastern Tennessee. The state of TN and the county in which we are building has a higher occurrence of radon gas than many other areas in the US -at least according to the US EPA.

Our build is still at the foundation stage and we expect framing to begin soon.

I'm leaning toward getting a certified radon contractor to install a mitigation system in the crawlspace; where a constantly running fan creates positive airflow to help vent radon gas from beneath the home.

Anyone here have any experience or expertise in this area? If so, I'd appreciate thoughts and advice.

Thanks-

My wife and I are also in the "foundation stage" building our retirement a.k.a. (gonna die here) house Mountain City, East Tennessee. I never even considered the Radon gas problem but I would sure be interested if it would affect a "walk out basement" house.

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[nmrugerdude]

My wife and I are also in the "foundation stage" building our retirement a.k.a. (gonna die here) house Mountain City, East Tennessee. I never even considered the Radon gas problem but I would sure be interested if it would affect a "walk out basement" house.

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I would get it checked before the house is all built

 

[fixitagain]

I would get it checked before the house is all built

Yea usually better and cheaper to get it done right before than try to fix it after.

Radon was a big concern many moons ago when I bought my first house. I'm sure it's still a concern it's just not talked about as much. Who needs an increased lung cancer risk. Good thing y'all are aware and considering mitigation in the early stages.

 

[RJF]

When selling my walk-out basement home, the buyers wanted a RADON check - something we never considered and spent little time in the basement anyway. So the tester came out and tested for it and it registered enough to need a mitigation system. What sorta bit was that since it tested "positive", it had to be advertised as such - and corrected before sale.

I didn't want to hand-off a problem to whatever buyer bought the house, so I forked over big bucks (about $1K all said) to do that right. Probably should have done that years earlier but never really considered it as we both smoked at the time.

It turns out the house was generally in a high-radon area (as is our present house), but generally at levels below requiring mitigation. The Radon guy said that after the heavy rains that had occurred the previous month, radon levels typically spike for a short period of time; that had it been checked a few weeks earlier or a few weeks later, the level would have be below that requiring mitigation. The mitigation system he installed was tied into the sump-pump system for ventilation. Our present house doesn't have a sump and has never needed it in the 16 years we've lived here.

I probably ought to do a radon check, since we're within about 20-30 miles of uranium deposits...

As with automobiles, factory-installed (i.i. designed in and built in) is always better than dealer-installed. Get the place tested and get it installed while the foundation work is being done. Always cheaper and better.

 

[rammerjammer]

Radon is real but very overblown. In my area of Nebraska it is almost impossible to not have high radon. When I sold my home I made it clear to buyers test all you want, I won't pay for mitigation. Mitigation may help a bit but I don't believe a tiny fan with a pvc pipe for exhaust is actually going to make much of a difference.

 

[Jack Ruger]

I won't say I have experience in this area, but because you have the new build, I don't know if code would allow for the exhaust pipe to run contained (like through a chase) within you house then penetrate the roof like your vent pipe for your wastewater system.

That way you don't have that big unit and 4" pipe going up the outside wall of your house.

Good that you can take care of it now though either way.

 

[mark40]

The system in our home was installed by the previous owner in 1997. We moved in in 2005 and had to replace the fan a couple of years later. We've done a couple tests over the years and all have been within acceptable levels. I'm in the basement a lot and the fan noise is not noticeable and there is a gauge that indicates the system is operational. We have a system like in the PDF, except the piping and motor are outside.

 

[crstrode]

We've done a couple tests over the years and all have been within acceptable levels.

"Acceptable levels" is the topic to investigate. EPA "acceptable levels" are about 1000 times lower than the actual threshold for any detectable increase in cancer risk.

Don't strain your brain worrying about radon. It is generally a whole lotta hooey.

Take it from a retired nuclear control systems engineer and radiation protection systems expert.

 

[mark40]

"Acceptable levels" is the topic to investigate. EPA "acceptable levels" are about 1000 times lower than the actual threshold for any detectable increase in cancer risk.

Thats good to know.


This is what the test kit stated:

RADON HEALTH RISK INFORMATION:
Radon is the second leading cause of lung cancer, after smoking. The more elevated a home's radon level, the greater the health risk to you and your family. Smokers and former smokers are at especially high risk.
Radon concentration is measured in picocuries per liter of air (pCi/L). The US Environmental Protection Agency and the Surgeon General strongly recommend taking further action when the home's radon test results are 4 pCi/L or greater. Even homes with very high levels can be reduced below 4 pCi/L. The EPA recommends that you use a NRPP/NRSB or state-approved contractor to correct radon problems. Radon levels less than 4 pCi/L still pose some risk and in many cases may be reduced. If the radon level in your home is between 2 pCi/L and 4 pCi/L, The US Environmental Protection Agency and the Surgeon General recommend that you consider correcting the problem in your home.

YOUR RADON TEST RESULTS:
RADON LEVEL: 1.0 pCi/L

 

[laidlerj]

In a lot of areas of the US, especially places like Florida, there are phosphate-containing minerals in the soil which also (because of similarities in chemistry) contain uranium. In the process of uranium decay, it produces (eventually) radon 222, a gas. This gas is (much) heavier than air, so it will pool in low-lying areas. It seeps through concrete, especially through small cracks or sumps.

Radon 222 has a half-life of 3.8 days and decays, through a sequence of intermediates, to lead. The health problem is that we breathe in radon 222 gas and it decays (by giving off an alpha particle) to polonium 218, which is a solid and remains in the lungs, eventually decaying (via four beta and two alpha particles) to lead 206 (which is stable). That’s a lot of radiation in close contact with sensitive lung tissues, and can significantly increase the risk of lung cancer. That said, the increase in lung cancer from radon was seen only in uranium miners and even then, only in those who smoked.

Long story, but that’s what the “big deal” about radon is.

Radon mitigation depends on how much uranium there is in your soil (essentially none, where I live) and what your sub-levels are like. In new construction in radon areas, they usually put some sort of membrane under the basement floor or in the crawlspace, with some means of venting gas trapped below the membrane to the outside. In high-radon areas, they often have to include active ventilation to keep radon from accumulating. Basements are usually not encouraged in those regions, because then there is a lot of connection between the underground and the living areas.

If your area is a high-radon area, there will be certified and licensed radon-mitigation contractors. Building with a crawlspace (as opposed to a basement or “slab-on-grade”) is preferred, because it gives an easily ventilated buffer space between the radon and the living areas.

Hope that helps.

 

[humboldt]

Also, lead paint is bad. However, if you call a lead paint inspector, I would be surprised if he didn't find lead paint somewhere. Think about the millions of children raised in homes with lead paint over the past 150 years. If your kid chews on the window sill, you have more problems than just lead paint.

 

[DCunniff]

In 2011 bought a house in WI, tested about 16 or so, very high. Was a bank sale, they paid for the mitigation. Was a house with a finished basement. No issues with the system still.

 

[Talldog]

Mitigation may help a bit but I don't believe a tiny fan with a pvc pipe for exhaust is actually going to make much of a difference.

My home was built in 2018, and the builder put in a passive system, which was the PVC pipe going from under the foundation to the roof. We monitored the radon level in the basement with a good quality detector for a few months, and it averaged in the mid-teens (4 pCi/L is the recommended max), so we had someone come in and install the fan in the attic. Since then, it averages less than 1 pCi/L. So yeah, they really work.

 

[Doc Holliday]

"Acceptable levels" is the topic to investigate. EPA "acceptable levels" are about 1000 times lower than the actual threshold for any detectable increase in cancer risk.

Don't strain your brain worrying about radon. It is generally a whole lotta hooey.

Take it from a retired nuclear control systems engineer and radiation protection systems expert.

Yes, nothing to worry about...

 

[exex]

Radon is real but very overblown. In my area of Nebraska it is almost impossible to not have high radon. When I sold my home I made it clear to buyers test all you want, I won't pay for mitigation. Mitigation may help a bit but I don't believe a tiny fan with a pvc pipe for exhaust is actually going to make much of a difference.

I had it done after a scary xray with my boy living in the basement. Tested and found over-safe level on a corner wall connecting a room addition to the basement. It was 9 versus acceptable of 4 (IIRC). Had professional install the mitigation fan to suck it out from under the basement floor.

Supposedly, radon over 'safe' is the equivalent of smoking a pack of cigarettes a day. Radon is low-radioactive gas emitted from clay in our area. Since radon rises, it seeps upward from the ground so it tends to circulate in living space above it.

 

[hlg]

Thank you all! It's great to have some real-life experiences to draw on.

We're still in the foundation stage and we are going to have a crawlspace. The crawlspace will conditioned by our GC. This area of TN is considered by the EPA to be in the 'red zone' for radon gas. From what I've read on the EPA site, it seems an active venting system in our future crawlspace would be the way to go.

I'll contact my GC to see if he has a sub he uses for this issue/concern and go from there.

Thanks again for the responses.

 

[hlg]

My wife and I are also in the "foundation stage" building our retirement a.k.a. (gonna die here) house Mountain City, East Tennessee. I never even considered the Radon gas problem but I would sure be interested if it would affect a "walk out basement" house.

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Here's a link you may want to check out.

Reducing Radon Levels at Home: New and Existing Construction

Pretty sure Mountain City is going to be in the "red zone" as well. (Beautiful country there ...and you all are really in for some rural livin'. Congrats!)

I'm going to contact my GC today to make sure we get a handle on this before the framing starts. Gonna be a whole lot cheaper to do it now than wait until the build.

 

[Iowegan]

I used to live in Ft Calhoun, NE (about 20 miles north of Omaha). I had my home tested for radon and found my basement was well beyond the safe limits. Instead of installing equipment, almost 5 years ago we decided to buy a new house across the river in Council Bluffs, IA .... another area well known for high radon levels. My new house has a radon evacuation system as do the other new houses in my neighborhood. I really don't know how it works but the tested levels are way below established standards so I would say it does work.