radon

[David K. Lee]

I'm doing my second inspection tomorrow, and noticed the house has a radon mitigation system. Should I have system checked by a pro, and how would I write it up. Thanks for suggestions.

[Larry D. Kage]

Originally Posted by dlee2

I'm doing my second inspection tomorrow, and noticed the house has a radon mitigation system. Should I have system checked by a pro, and how would I write it up. Thanks for suggestions.

Run! Run! The home is bleeding a deadly gas!!!


...but seriously...possibly:

The home appears to have a Radon mitigating system installed.

Although this system is not part of our normal home inspection, the client may want to have the Radon levels professionally tested to verify the efficiency of the system.

[gbeaumont]

David,

there are two types of radon mitigation systems that you may encounter.

The first is a passive system where a (normally PVC) pipe is brought up through the basement fllor and vents to the outside of the structure above the roof.

The second system is a powered one where an in line fan is placed into the pipe run and perminantly keeps the sub-basement floor area under negative pressure. these are normally up in the attic although you will sometimes see them on the outside of the home.

Other than checking for damage to the piping and that the fan is running (if installed) there is really nothing to check.

Regards

Gerry

[Larry D. Kage]

Originally Posted by gbeaumont

Other than checking for damage to the piping and that the fan is running (if installed) there is really nothing to check.

Regards

Gerry

Gerry, I'm looking forward to learning more at the convention but as long as this popped up, let me ask:

If someone has their home tested and it is determined that a passive system will work, will it always work even if the radon levels increase?

I don't understand Radon enough to state that once it is mitigated for the tested reading taken at the time it will always be removed from the home.

[Joseph Hagarty, CMI]

http://www.ashi.org/members/ashidocs..._Checklist.PDF

http://www.epa.gov/radon/images/ashicklst.pdf

http://www.epa.gov/radon/zonemap/kentucky.htm

http://chfs.ky.gov/dph/info/phps/radongas.htm

[Larry D. Kage]

Originally Posted by jhagarty

http://www.ashi.org/members/ashidocs..._Checklist.PDF

Thanks Joe, good post, I had and idea that would have to be the case.

[Joseph Hagarty, CMI]

EPA has a great deal of information with regard to Radon.

January is National Radon Action Month

http://www.epa.gov/radon/

[Larry D. Kage]

Originally Posted by jhagarty

EPA has a great deal of information with regard to Radon.

January is National Radon Action Month

http://www.epa.gov/radon/

Oh, I see you added more links. I'll check those too.

Appreciate the help.

Thanks

[Caoimhín P. Connell]

Originally Posted by lkage

If someone has their home tested and it is determined that a passive system will work, will it always work even if the radon levels increase?

Mr. Kage:

Radon systems are mitigation systems, not elimination systems. As such, the efficacy of the system will be incumbent on the original level of radon in the structure.

It’s kind of like playing the numbers game. The system is capable of moving only a specific quantity of air or producing a specific pressure reduction across the slab. Those parameters are independent of the amount of radon present and therefore, the resulting concentration in the home will rise and fall as a function of the concentration in the sub-slab. The actual reduction (ratio of inside concentration to subslab concentration) will remain the same.

At some point, it is possible that the subslab concentration would be so high that the reduction is insufficient to ensure the indoor concentration is below recommended concentrations.

If you interested in learning something else about radon, you may find my web discussion on radon interesting:

www.forensic-applications.com/radon/radon.html

Hope that helps.

Cheers,
Caoimhín P. Connell
Forensic Industrial Hygienist

www.forensic-applications.com


(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG

[Joe Funderburk, CMI]

Ask This Old House had a show on this morning about radon and radon mitigation. It was very detailed and interesting.

[kfulton]

If they have not tested with-in two years we recommend testing. We had a house with an active mitigation system this summer. Our client took our recommendation. The agents were disgusted and thought we were trying to sell a radon test. Who makes any real money off these anyway? So we test... pow... 22 picos!

We are just looking out for #1,... our clients.

If you had a natural source of any other poison seeping into your home, you would monitor the hell out of it. Radon is the "out of site of out of mind" issue in home indoor air quality.

Take nothing for granted.

Kelley

[Caoimhín P. Connell]

Originally Posted by kfulton

So we test... pow... 22 picos!

Hello Mr. Fulton:

Of course the 22 pCi/l reading has perhaps only about a 10% chance of being correct. The confidence intervals of the reading are so large that the actual reading later in the week could have been 0.1 pCi/l and be just as valid.

You may be interested in reading the thread on the myths of radon monitoring raised on another board, and in particular my discussion posted August 17, 2005 on that thread (http://inspectionnews.com/ubb/Forum5/HTML/000221.html).

Cheers,
Caoimhín P. Connell
Forensic Industrial Hygienist

www.forensic-applications.com

(The opinions expressed here are exclusively my personal opinions and do not necessarily reflect my professional opinion, opinion of my employer, agency, peers, or professional affiliates. The above post is for information only and does not reflect professional advice and is not intended to supercede the professional advice of others.)

AMDG

[Larry D. Kage]

Mr. Connell,

Thank you, as usual, you supply a wealth of information.

I don't know a lot about radon but I'm learning and I thought, as someone else mentioned, that there should be more to monitoring it than just checking the mitigation pipes and fan.

I will check your links.

Thanks again.

[Larry D. Kage]

Originally Posted by Caoimhín P. Connell

You may be interested in reading the thread on the myths of radon monitoring raised on another board, and in particular my discussion posted August 17, 2005 on that thread (http://inspectionnews.com/ubb/Forum5/HTML/000221.html).

I just got back from reading 1/2 of that and am bleary eyed!

I'll try it again later.

[rwheeler]

A few points come to mind:

The EPA recommends that ALL homes be tested for radon, and recommends that homes with a radon mitigtation system installed by re-tested every two years. This is to ensure that the mitigation system is functioning and that the source strength (ie radon sources underground) have not drastically changed.

The function and efficiency of a radon mitigation system should only be commented on by a certified radon mitigation specilaist in your state. The only way to accurately test this is to have a radon test done in the home, adhering to all EPA and state testing protocols.

A home inspector who is not a radon professional should state and disclaim these facts in his report, just as you would with any other technical field that is outside the bounds of a normal home inspection.

A previous post stated that a reading of 22pCi/l could also be a .1pCi/l. Modern testing devices, especially continuous radon gas monitors, are very accurate and are required to be periodically re-calibrated by a nationally certified lab. These monitors usually have some kind of tampering alerts on their written reports to indicate if the hourly readings appear to have been compromised. This is a huge step forward from the days of activated charcoal canisters, which are susceptible to both tampering and user errors, but have no way of reporting these abnormalities in data.

Brad Wheeler
Gulf Coast Inspections and Testing, Inc