OT: Testing for radon gas in your home

[benb]

It's mandatory here, IIRC you can't sell the house without having it tested and it is always part of inspections.

Ours was OK when we bought our house 10 years ago, we have been thinking about re-testing even though we're not selling, although I'm not sure what natural process would cause a house to go from OK to bad. The whole thing is it's a radioactive gas.. there's not much that would cause it to increase. If it's present it naturally degrades over time, it shouldn't get worse unless something is happening in the geology under the house.

[zap]

We tested the last two houses we purchased.

The house in Maryland was in an area known to have higher levels of radon. We asked the seller to test for radon and the reading came back just above 4.0 pCi/L. The seller had to put in a mitigation system. Multiple testing (over many years including when we sold the home) including one time when the ground was frozen for two + weeks...all readings were below 2.0 pCi/L.

Our current house in NC was tested in January during a cold snap and came back below 2.0. I still went ahead and sealed gaps between the concrete slab and the footing.

[batman1425]

Originally Posted by redir

The same system that Potatoe shows above and yes the levels are gone. It creates a sink in the system. Basically pressure so all the gas (source) moves to the sink and then gets blown out above roof line. The fan runs 24/7 365 days till it burns out then you replace it. You never turn it off unless maintaing it.

This - that's the standard system. Cut a hole in the slab, dig out a bucket or two of fill from the hole, put a cap on with to seal it, an inline pump to create negative pressure and draw air trapped under the foundation to the hole and run the exhaust to the roofline. The two that were put in prior to purchase in 2 homes we've owned cost 1k-1.5k installed.

Make sure to get a follow up test after installation to confirm it is working if you don't have a continuous monitor on your unit. The places that did our had a guarantee that if the pump didn't reduce pCi/L below the federal cutoff, they would do additional mitigation till it passed.

[C40_guy]

We've put in two systems. In our area, they run around $1500. Each time I specified no outdoor piping. While it takes a bit more work to run the pipe to the roof internally, it avoids that eyesore of the white 4" pipe exiting the house at basement level, going all the way to the roof peak.

A good installer should be able to work with you to design a system that works.

We test annually using the mail-in kits...which, by the way, have expiration dates...so don't order several to use over time.

[benb]

After my previous post I went and looked up more on Radon.

It's a byproduct of the decay of uranium and thorium. Radon has a half-life of only 3.8 days so it disappears really fast.

But if you've got it then it's coming from uranium & thorium in the ground in your area, those decay over geologic time scale, so there's continuous production of radon.

Sounds like if you've got it then it never goes away but if you don't have much it's not likely to increase.

[echappist]

If my trainer is in the basement (as opposed to ground level), how much more concerned should i be?

[ORMojo]

Originally Posted by benb

After my previous post I went and looked up more on Radon.

It's a byproduct of the decay of uranium and thorium. Radon has a half-life of only 3.8 days so it disappears really fast.

But if you've got it then it's coming from uranium & thorium in the ground in your area, those decay over geologic time scale, so there's continuous production of radon.

Sounds like if you've got it then it never goes away but if you don't have much it's not likely to increase.

Yes, that's it. Aside from seasonal variations (generally, higher concentrations in winter), it is a long-term situation.

Fortunately, we live in a low-radon area, but we have still tested every home we have purchased.

OR_Radon_Capture.jpg

[ORMojo]

Originally Posted by echappist

If my trainer is in the basement (as opposed to ground level), how much more concerned should i be?

As much as anything, that would depend on how the air exchange differs in your basement from the upper levels of your house. If there is more limited fresh air exchange in the basement, then there will be an increased risk of higher concentrations of radon.

[R3awak3n]

Originally Posted by benb

It's mandatory here, IIRC you can't sell the house without having it tested and it is always part of inspections.

Ours was OK when we bought our house 10 years ago, we have been thinking about re-testing even though we're not selling, although I'm not sure what natural process would cause a house to go from OK to bad. The whole thing is it's a radioactive gas.. there's not much that would cause it to increase. If it's present it naturally degrades over time, it shouldn't get worse unless something is happening in the geology under the house.

same here. when we bought this place they tested it. Apparently some in the basement (wet basement, can't really be used so I don't care) but fine in the house.

[rwsaunders]

Originally Posted by Veloo

What time of mitigation did you guys put in place besides the sub slab piping that brought concentration down to acceptable levels?

Essentially the same system as OP indicated. We built our home in 1999 and I installed a system under the basement slab as a preventive measure, given the history of radon in the region. Pretty simple really and inexpensive, as we made the decision when designing the home.

I’d venture to say that your national or regional health system or building regulatory agency has identified recommended radon mitigation systems for both new and retrofit situations.

[echappist]

Originally Posted by ORMojo

As much as anything, that would depend on how the air exchange differs in your basement from the upper levels of your house. If there is more limited fresh air exchange in the basement, then there will be an increased risk of higher concentrations of radon.

Thank you

Also, where did you obtain the map for Oregon, is it from the state? Im wondering if Wisc has something similar

[rwsaunders]

Originally Posted by echappist

Thank you

Also, where did you obtain the map for Oregon, is it from the state? Im wondering if Wisc has something similar

Good info...PA’s site has informative videos as well.

https://www.epa.gov/radon/epa-map-radon-zones

https://www.dep.pa.gov/Business/Radi...-the-home.aspx

https://www.dhs.wisconsin.gov/radon/infocenters.htm

[ORMojo]

Originally Posted by echappist

Thank you

Also, where did you obtain the map for Oregon, is it from the state? Im wondering if Wisc has something similar

Yes, from State of Oregon

Here is Wisconsin's. Interactive map, so you can play with it for your locale.
WI_Radon_Capture.jpg

Unfortunately, it looks like your area has a relatively high likelihood of high concentrations of radon.
Madison_WI_Radon_Capture.jpg

[C40_guy]

Originally Posted by benb

Sounds like if you've got it then it never goes away but if you don't have much it's not likely to increase.

When we bought a house in 1990, we tested for radon and the levels were quite low. 15 years later we retested and the levels had risen just enough to warrant remediation.

[Jaybee]

Originally Posted by C40_guy

When we bought a house in 1990, we tested for radon and the levels were quite low. 15 years later we retested and the levels had risen just enough to warrant remediation.

The standard 48 hour test isn’t a long enough period to capture natural fluctuations in the subsurface. Test a few times if you live in a high-risk area.