Radon question

[Stick in Mud]

Hello all,

We just bought a house (built in 2001) that (BARELY) has too high levels of radon (it was over the mandatory disclosure level by a tenth or two). The sellers did reduce the value of the home $1500 to cover a radon mitigation system, but we're thinking of delaying actually putting one in because 1) the sellers had sealed up the entire house (by caulking and taping the windows shut and some doors shut), 2) the sellers had taped up the outdoor air-intake for the furnace and moved it inside just off the furnace.

Of course, the furnace is in the same room as the sump pump hole, so the sellers sealed up the house and then circulated the radon throughout the house via the furnace.

And because we're a bit low on cash at the moment, we're wondering if uncaulking/untaping the windows and reopening the original air intake would have any effect on the radon levels, at least allowing us to save up some $$ for a while before installing the mitigation system. First time homebuyer here, so the question might be dumb. If so, just tell me.

Oh, and it's nice to FINALLY be able to post something in the "home improvement" forum...I don't think they have an "apartment improvement" forum, do they?

[reddog]

Mike,

A little more info please..

is the basement finished? If so, what kind of flooring?

Do you know what is under the concrete floor of the basement? Is it insulated with foam, possibly. Is there a drainage bed of crushed rock or pea rock subslab? Is there a vapor barrier?

What kind of lid is on the sump basin?

Is there an air exchanger of any kind in the home. Do you know if its a balanced system, or an exhaust only?

Unsealing some of the things the previous owner sealed up, could very well increase your levels, by increasing the "stack effect" on the house, not to mention your heating bills..

Radon is very easy to control, if you can isolate the source..

Radon is very easy to stop...

[Stick in Mud]

Thanks for the reply, reddog.

As far as I know, there's a drainage bed of crushed rock.

The house does have an air exchanger. Not sure about what type of system...

The basement is completely finished and carpeted.

The lid on the sump pump basin, which is currently under a bunch of shelving, wasn't even attached to the basin.

I hope that helps...this is all very new to me.

[reddog]

Mike,

The single largest opening in your slab, is your sump hole. If you have an A2A heat exchanger, typically that are either balanced, or slightly negative in pressure..which exacerbates the radon issue.

Back to the sump.. What kind of a pump is in there? A submersible, or a tower type.. If this were my home, and you are just barely above acceptable levels, then I would find a way to seal the sump lid as the first option, even if it wasnt perfectly sealed tight, anything is better than a 24 inch hole in the floor with connectivity to the subslab drainage bed. then, I would test again 30 days after retrofitting the lid.

If the levels are still high, then I would be in line with a relatively simple radon mitigation system, but I wouldnt think you would need it..

[Stick in Mud]

The sellers still have stuff in the house, and most of their storage is located directly over the hole, so I can't get back there to see what's in it. When they move out, I'll be able to move the shelves (or they'll take them with them) to see what's up.

[Tom7227]

Please help educate me. I am serious about asking as I have no idea at all.

Why do you care?

What can radon do to you, at what levels, and over what period of time?

I have never tested my home for radon and I suspect that there is some of it in the house as it is 50+ years old and has two sumps, one of which has no lid at all.

The little I know about the remediation is that there is some sort of jobberdo that pumps stuff out from under the slab. Since I am pretty sure that my slab sits on whatever dirt/clay was there when the house was built I guess I can't see much chance of getting much air movement even if I were to cut a hole in the cement.

Thanks for your time.

Tom

[delcecchi]

Please help educate me. I am serious about asking as I have no idea at all.

Why do you care?

What can radon do to you, at what levels, and over what period of time?

I have never tested my home for radon and I suspect that there is some of it in the house as it is 50+ years old and has two sumps, one of which has no lid at all.

The little I know about the remediation is that there is some sort of jobberdo that pumps stuff out from under the slab. Since I am pretty sure that my slab sits on whatever dirt/clay was there when the house was built I guess I can't see much chance of getting much air movement even if I were to cut a hole in the cement.

Thanks for your time.

Tom

Prolonged exposure to high levels of Radon increases the risk of lung cancer. It affects smokers much more. The more Radon and the longer the exposure the more the risk goes up. The arbitrary threshold the authorities have set is 4 picoCuries per liter.

There are sites on the net that explain how bad a problem it can be.

It appears that Ramsey county doesn't have too big a problem

Radon in Ramsey County

Mn Radon by zip code

[Stick in Mud]

I care because (apparently) it's the second-leading cause of lung cancer (after smoking, of course). Plus, with my predilection for cigars, especially after a few stouts and IPA's (or Keystones, more likely, after putting up the down payment ), I'd be more at risk than a non-smoker.

Now, to the specifics of your question, I'm not exactly sure. The levels in the house aren't all that high, and I don't know with any specificity the risk they do pose, but it is something that I'm concerned about, though obviously not enough to automatically install the mitigation system without asking some questions first.

[delcecchi]

From EPA

Radon Risk If You Smoke

Radon Level If 1,000 people who smoked were exposed to this level over a lifetime*...

20 pCi/L About 260 people could get lung cancer

10 pCi/L About 150 people could get lung cancer

8 pCi/L About 120 people could get lung cancer

4 pCi/L About 62 people could get lung cancer

2 pCi/L About 32 people could get lung cancer

1.3 pCi/L About 20 people could get lung cancer (Average indoor radon level)

(Reducing radon levels below 2 pCi/L is difficult.)

0.4 pCi/L About 3 people could get lung cancer (Average outdoor radon level)

Note: If you are a former smoker, your risk may be lower.

* Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003).

Radon Risk If You've Never Smoked

Radon Level If 1,000 people who never smoked were exposed to this level over a lifetime*...

20 pCi/L About 36 people could get lung cancer

10 pCi/L About 18 people could get lung cancer

8 pCi/L About 15 people could get lung cancer

4 pCi/L About 7 people could get lung cancer

2 pCi/L About 4 person could get lung cancer

1.3 pCi/L About 2 people could get lung cancer (Average indoor radon level) (Reducing radon levels below

2 pCi/L is difficult.)

0.4 pCi/L (Average outdoor radon level)

Note: If you are a former smoker, your risk may be higher.

* Lifetime risk of lung cancer deaths from EPA Assessment of Risks from Radon in Homes (EPA 402-R-03-003).

** Comparison data calculated using the Centers for Disease Control and Prevention's 1999-2001 National Center for Injury Prevention and Control Reports.

----------------------

They don't seem to say what "lifetime exposure" means? Is that if I live in that level 24/7? So I think I ought to derate the risk by the percent of time I am not exposed to that. But I could be incorrect.

OK, pressing on to http://www.cheec.uiowa.edu/misc/radon.html

It seems as if 15 years of exposure to an average of 4 pci/l increases the odds of lung cancer by about 50%

"The Iowa Radon Lung Cancer Study's estimated excess odds at 11 WLM5-19 (roughly equivalent to a 15-year exposure at an average radon exposure of 4 pCi/L) averaged 0.50 " (for women)

Also note that the absolute risk for lung cancer in non-smokers is fairly low so adding 50% to it may not be much of an absolute increase.

[FlagsDown]

Technically, you have a corrupted test.

After you take possession, and correct the deficiencies you've identified, get a couple of $25 test canisters from a hardware store, and retest. Leave them for 30-90 days, mail them to a lab for results.

You've got nothing to lose. You control the testing conditions and you received the money for the mitigation system if needed after retesting.

Google "epa radon" for more info.

Google "Caoimhín P. Connell radon risk and reality" for an opposing viewpoint on radon

[Stick in Mud]

Wow, thanks both Del and FD for the info....especially the "alternate viewpoint" link, too.

We'll try to save a bit of money by reducing the levels without putting in the mitigation system, but if it doesn't work--or if the levels don't go down very much--we'll put it in. Helps that they reduced the price of the house for it.

[Redlantern]

These days, most houses that are built have a sump basket (for ground water) that has a sealed lid. Venting the sump basket for ground waater isn't required but one way to try to rid the radon from the home is to vent the sump basket. It's basically just running the vent from the basket through the roof of the house, much like a plumbing vent.

[reddog]

These days, most houses that are built have a sump basket (for ground water) that has a sealed lid. Venting the sump basket for ground waater isn't required but one way to try to rid the radon from the home is to vent the sump basket. It's basically just running the vent from the basket through the roof of the house, much like a plumbing vent.

Terminating out the roof of the house, doesnt require any type of inline fan, it is dependent on stack effect in the house.. Delta T. (temperature differential) is the driving force. While it is much like a plumbing vent, the plumbing vent operates on the vacuum properties of water, where as a passive radon vent only operates when there is sufficient stack effect. The problem typically is, its usually hard to fish a new 4inch line from the sump to out the roof.

When you cant get a line fished thru the structure, then it is much easier to simply run a 4 inch pvc line from the sump basin (sealed) to the rim joist and exit out the side of the house. There is not enough temp diff to drive this system, so an inline fan will be needed. You can buy a FanTech 4 inch inline fan for $208.00 from Grainger, and thats the first place I looked.. If it were my property, and I needed remediation, this is the route I would go. It will offer positive ventilation, 100% of the time, compared to a passive system, that is temperature dependent for a drive system.. Works well in the winter, when there is a large delta T, but not so effective in the summer, when the opposite is happening..

[delcecchi]

For some reason it is recommended that radon be vented out the roof, and the remediation systems typically have a fan. I am not totally clear on why they want the vent on the roof instead of the side.

{looked it up. It is said that air sucked from below the slab can be VERY HIGH in radon, like in the hundreds or more of pci/l, and so you want to exhaust it where it will blow away and not blow back into a window or near any people}

If I were at 4.1 and a non smoker and wasn't planning on selling soon I might wait before doing anything expensive.

[rundrave]

simply run a 4 inch pvc line from the sump basin (sealed) to the rim joist and exit out the side of the house. There is not enough temp diff to drive this system, so an inline fan will be needed. You can buy a FanTech 4 inch inline fan for $208.00 from Grainger, and thats the first place I looked.. If it were my property, and I needed remediation, this is the route I would go. It will offer positive ventilation, 100% of the time, compared to a passive system, that is temperature dependent for a drive system.. Works well in the winter, when there is a large delta T, but not so effective in the summer, when the opposite is happening..

this is what was done in the home I purchased 2 years ago. Seeing how simple of solution this was and what it cost me and the seller I wish I would have just took the money and did it myself. Very simple install. I should start installing these for a living at the price they get. I would be able to retire pretty quick.

[Redlantern]

reddog, a little off topic of the original question but you mentioned plumbing vents working by vacuum. It's actually quite the opposite, the idea is to keep the pipes at atmospheric pressure to reduce vacuum and keep traps from being sucked dry.

[Tom7227]

I tried to read the Iowa study that is linked above on this thread. Somewhat simply they took a bunch of housewives who seldom left the house and never moved and were stuck in Iowa. The area has high radon readings. The statistical manipulations were hard to understand but if I got anything out of it it was that no one really got sick. Combine that with the fact that I think the radon thing as pretty much fallen off the radar - at least my radar - and I wonder whether this is a big deal thing or not. I admit that I am a FOWG who hasn't been in the market for a house for a long time but I haven't seen any notes about radon equipment in any detailed real estate listings, whatever.

So, are you folks the only ones that care about this?

[reddog]

reddog, a little off topic of the original question but you mentioned plumbing vents working by vacuum. It's actually quite the opposite, the idea is to keep the pipes at atmospheric pressure to reduce vacuum and keep traps from being sucked dry.

Thats kinda what I meant, just didnt come out that way..

[delcecchi]

I tried to read the Iowa study that is linked above on this thread. Somewhat simply they took a bunch of housewives who seldom left the house and never moved and were stuck in Iowa. The area has high radon readings. The statistical manipulations were hard to understand but if I got anything out of it it was that no one really got sick. Combine that with the fact that I think the radon thing as pretty much fallen off the radar - at least my radar - and I wonder whether this is a big deal thing or not. I admit that I am a FOWG who hasn't been in the market for a house for a long time but I haven't seen any notes about radon equipment in any detailed real estate listings, whatever.

So, are you folks the only ones that care about this?

Yeah that there science stuff is complicated, not like the simple english used by lawyers.

As I understand it there is a standard of 4 pci/l. If your house is above that and you know it you have to disclose it to the buyer. If you don't know you don't have to disclose. At least that's the way I understand it to be. (statutes 513.52 to 513.60)

[Stick in Mud]

You are correct, Del. The EPA has set the mandatory disclosure level, and most of the time sellers don't know if the house has high levels or not....so when they're writing the listing, it won't show up.

Most buyers also don't test for it, either, but if they do, and the levels are over the allowed amounts, the sellers almost always install the mitigation system and/or deduct the amount in an addendum to the original contract.

I asked our realtor how often there's a conflict between buyer and seller after the radon is "discovered," and he said in his experience, only one seller has not either installed the system or reduced the price.

[delcecchi]

You are correct, Del. The EPA has set the mandatory disclosure level, and most of the time sellers don't know if the house has high levels or not....so when they're writing the listing, it won't show up.

Most buyers also don't test for it, either, but if they do, and the levels are over the allowed amounts, the sellers almost always install the mitigation system and/or deduct the amount in an addendum to the original contract.

I asked our realtor how often there's a conflict between buyer and seller after the radon is "discovered," and he said in his experience, only one seller has not either installed the system or reduced the price.

That is the downside of testing.... You don't have to disclose what you don't know. I don't know how many home inspections include radon testing.

[Stick in Mud]

The radon testing--at least when done by the inspector--is $100-150, so a lot of buyers skip it. The testers you can buy at the home improvement stores work just as well, but they take longer than the time allowed to do the inspection and write up the addendum. The fancy inspector-grade radon test does it in a day or two.

Of course, there's a bit of cost-benefit analysis to do here if you're a buyer. The extra cost of the radon testing might be outweighed by 1) money off the house if you're not concerned about getting cancer and don't fix it, 2) a safer house if the sellers are willing to put in the mitigation system, 3) a bit of hassle for the buyer if the price is deducted but the buyer has to fix it, or 4) a higher risk of getting lung cancer if you ignore the issue and don't test for it. And yes, there's a debate about the reliability and the validity of the radon tests (and about the actual danger of radon in a home), but we decided that (with my predilection for a cigar or two a month) it was worth the upfront cost.

Of course, you can wait until you're living in the house to do a radon test (and save the money on the expensive inspection), but at that point the sellers wouldn't have any skin in the game, so any fixes would be on you.

At least that's how I understand it.

[Tom7227]

Thank you to those who responded to my questions.

Tom

[chasineyes]

I noticed there was a story about Radon this past weekend and got me thinking. If radon is active in the ground, wouldn't that permeate (sp) into the corn or soybean crops? I wonder cuz my home/development is built on a old corn/bean field.

[reddog]

Radon has been around forever.. It has only been since the energy crisis of the 80s that it moved to the forefront, with the tightening of houses. Houses prior, werent very tight, so radon moved thru a house quickly with air movement..

Todays tigher houses trap radon, particularly if they are operated at a slightly negative pressure with their ventilation system. Most builders know how to build a fairly tight house, but dont know the importance of a sub slab radon barrier.

One of the presenters at EEBA seminars said that a piece of paper would stop radon from entering the house, as long as it was continuous. The problem is, getting a sub slab piece of paper that was durable enough.

Radon is very easy to manage, if you know when and where to set up the road block..

Corn/beans have little to do with radon..