Hello,
I have a client wanting a radon test for their mobile home. It sits up on blocks, thus it has space between the ground and the bottom of the mobile home. I would think this would keep most if not all radon out of the structure. Is a radon test inside a Mobile home that sits above the ground something that other inspectors do? Thanks for the help!
Hi Austin,
I’ve never had the opportunity to test a mobile home but found the below link. Take a look at the 4th paragraph…
I would explain to them that the space between the home and the ground should reduce any levels of direct Radon exposure, but if they want it tested for peace of mind, by all means, test it for them.
It’s ironic to see this question today. I inspected a manufactured home today that had a passive system installed. First for me. Client passed on having me test. (yes, that is a PB water line running across the top of the pic).
Thanks Will. It’s good to hear it from the source!
That’s the route I was planning on going. I wouldn’t mind charging them for it. Just wanted them to be educated first if there wasn’t much of a chance of radon being in the structure since there was the gap between.
That is interesting. Perfect timing! Haha. Does that home have a crawlspace, is that where that is located?
Yes, in the crawl. This crawlspace was fully encapsulated.
Is the foundation between the blocks enclosed with skirting? Does it have vents? Treat the area under the mobile home like a crawlspace or pier foundation. Close the vents if present, and in this case wait 12 hours after closing the vents before initiating your test. For crawlspace or pier foundations, you test the main floor, inside the mobile home. Testing the crawlspace is just a FYI.
When a potential client wants to hire you , say thank you and set up the test, tell them it is a great idea, however without a test there is no for sure way to know , do the test
Not necessarily true! Never speculate for the client. Always test. I’ve tested very high radon on homes with a crawlspace, slab, and basement. Foundation has nothing to do with radon levels in the home, except maybe an open pier foundation.
From the client on the phone, it sounded like it was a piered block foundation with lattice between the piers. Don’t think it has vents. I appreciate the info.
That is good advice. I was just thinking with all that open space, it would disperse before it would enter structure. But that makes sense.
The foundation does have allot to do with Radon levels. If it doesn’t matter then keeping closed conditions doesn’t matter either. Crawlspaces will be design have less radon as it has an escape path through the vents, but so many get closed or blocked in the winter, and never reopened.
For a house with a crawlspace that is vented with louvered vents, testing protocol is to close those vents 12 hours prior to starting the test. You need to have closed house conditions established at least 12 hours prior to initiating your radon test. I expect you know and practice that, right?
From my experience, I cannot predict the possibility of high radon based on foundation type. I’ve been licensed to test for at least three years now. It’s totally hit and miss; even with adjacent structures on the same property. My testing records show absolutely no correlation between radon level and any particular foundation type, except for an open air pier foundation with no skirting.
Maybe your experience is different… Do you close the crawlspace vents 12 hours prior to starting your tests?
Lots of good advice on this thread but wanted to point out that the only way to know is to test. This is from the ANSI/AARST MAH 2023, the latest radon testing standards for homes.
“ 2.1 Which Homes Should Be Tested?
Informative Advisory—Any home on any parcel of land can have a radon problem. Testing is the only way to know.
Every home should be tested to include new and old homes; tightly sealed and drafty homes; and homeswith or without basements or crawl spaces. Radon concentrations cannot be predicted based on state, local or neighborhood radon measurements.
Please provide me with this information. Yes house needs to be in closed conditions. But that only includes windows and doors . Some crawlspace vents do not close, and that’s not the normal way a house is. You will get inaccurate results. And no I do not close crawlspace vents, and I do not block attic ventilation either.
I just read over the EPA radon booklet. There is no mention of closing crawlspace vents. It is not a requirement. You are wasting your time closing them the day before the testing.
It all depends on your climate/location. If it is likely that a person will have them closed for a significant portion of a year, then they should be closed for the test.
You mean like in Northern Minnesota where winters are 5+ months long and often -30f degrees not including the wind chill???
