Also, because I'm just being contrarian about this: "a host of health issues" doesn't sound right. From what the EPA says, exposure to radon may contribute to developing lung cancer.

I would recommend viewing the website at this link for more information about radon. https://canceriowa.org/breathing-easier/.Radon is the second leading cause of lung cancer after smoking. The sun is the leading environmental cause of cancer (e.g., skin cancer), but fortunately the survival rate is very good for skin cancer - even for melanoma. Radon is one of the leading environmental causes of cancer-related death. When someone develops lung cancer, there is a less than a 20% chance of survival 5 years later.  It is worth mentioning that radon mitigation is also a covered expense under many flexible health care spending accounts.

Do what you want. If you get cancer don't come here and whine about ti.

Chad, I bet you’re fun to be around aren’t you?

The repair is dubious at best. A pit, a pipe, and a fan is hardly a ventilation system. Radon guys also like to pretend concrete is a impervious system.

Concrete in good condition is airtight, so the sub-slab zone can be depressurized to evacuate the air and other gasses below the slab, assuming the slab is over a gas-permeable layer. I'm not convinced there is often a gas-permeable layer under most older slabs.

Wood Guy this slab is from 1927, so....nope.

"Airtight" concrete is not. It's permeable; vapor drive issues are common. And that's a larger molecule water, not just a gas molecule. What all this comes down to is how much negative pressure will it take to draw the gas to equalize, versus how much pressure it takes to drive through a 4" concrete slab. And at some point, you'll draw air through the slab from the basement quicker than gas from the other side of the basement. So, if you lack a vapor barrier and gravel sub base, can you really draw gas through several feet of compacted earth with less resistance than drawing it through a few inches of concrete? Probably not; that's why a lot of these retro-fit systems are shit. You kind of need that transport layer for the system to work. That means if she's concerned, she'll probably have to pull the slab, put in the necessary components, etc. making this a lot more expensive.

Vapor and air move through materials differently, via vapor pressure differential vs. air pressure differential. Many materials are considered airtight but vapor permeable. How long would you last sealed in a concrete box? Not long, because it's considered airtight (equivalent to drywall). 

Depressurizing the sub-slab zone only requires that the concrete is less air-permeable than the soil. I fully agree that if the concrete is LESS air-permeable than the soil than you have a problem. Of course on new construction it makes sense to use a plastic vapor retarder, as well as a gas-permeable layer of crushed stone and a perforated perimeter pipe.

That should have been, "if concrete is MORE air-permeable than the soil than you have a problem."

you've been indiana too long...

When I lived in Chicago as a kid, my family's house was haunted. Maybe it was just radon.

I've heard sun causes cancer. 5.4 million basal cell carcinoma diagnoses per year versus the 20k lung cancer from radon. I get it Donna... we're also of a age where we lived 'dangerous lives' without helmets, car seats and seat belts.

I do wear SPF 45 every single day on my face, though.

tbh Donna i couldn't tell if you're post is intended as a joke or not. being unwilling to consider the possibilities of intangible risk is the essential feature of denialism against issues like global warming or vaccines. radon is much less important than either of those, but dealing with it isn't particularly difficult either.

you've also demonstrated the fallacy of interpreting undesired recommendations as being evidence of a conspiracy.

I’m absolutely aware that that’s the behavior I’m exhibiting, midlander. So in a way it’s a joke. But it’s also about being skeptical and aware of how grifters can use fear to manipulate. All those people driving huge-ass SUVs and square-front trucks? That’s fear-driven, not logic-based. I know that in the construction field it’s extremely common, despite our best efforts as part of that field, for people to take advantage of others.

Donna is right. The mitigation companies have a racket. They know that the EPA action limit of 4 pico curries per liter is the health limit. This is a totally fictional number to help generate fear and improve sales. If you get 20-25 piC/l then you might consider mitigation. The mitigators and equipment suppliers know 40-50% of previously 'mitigated' homes have a suction fan which has failed. Where are all the dead bodies?

This is exactly what I was thinking. We've had abatement contractors try to screw our clients so many times. One said that because the floor of one room tested positive, then floor along the pathway to the room also has to be abated because the contractor will be tracking it down the hall. Oh and because the floor of the pathway has to be abated, then some of it will become airborne as he is carrying it out, then the walls and ceiling of the pathway also need to be abated... and on it went.

Right? They act like asbestos is plutonium or something. My grandfather was an HVAC contractor back in the old days when they used asbestos duct liners, etc. He used to have big piles of asbestos shreds in his shop, the kind that is actually a health hazard (e.g. amosite and tremolite), not the kind that isn't (e.g. encapsulated chrysotile). Nobody wore respirators working with it. My mother and her sisters used to play right around it when they were little. None of them ever showed any ill health effects from it. Now, that doesn't mean it wasn't dangerous or that people haven't developed severe health problems from exposure to friable asbestos fragments. But it isn't instantly lethal, nor is it deserving of all the fear surrounding it.

I abated the asbestos duct wrap in my old house myself, following the very simple guidelines that some state (Iowa? Nebraska? Can't recall) had on their government website: wear coveralls, gloves, and a respirator; spray the hell out of all of the material with soapy water until it's sopping wet, then scrape it into bags that you twist-tie shut, label HAZARDOUS, and dispose of properly (at a tox drop). I tell people I did this and they FREAK OUT at what a risk-taker I am (then they hop into their car and drive away while texting and applying lipstick simultaneously).

I did the same on my own home remodel years ago. It was No Big Deal. Certainly not something that deserved a hazmat team at $1000 per hour.

I'm working on a project where we're abating asbestos-cement shingles. Every meeting, someone raises the question of whether the whole building will have to be tented, workers wearing bunny suits, the whole disaster movie scenario. Guys, they're shingles - wear gloves and basic dust masks, use a little extra care to avoid breaking them when taking them off the building, then dispose of them properly.

I removed a fair amount of asbestos in my construction days, before I understood all of the materials that contained it. And sometimes even pipe wraps, to "save my clients money." Twenty years later I have reduced lung function. One of my grandfathers died at 61 from what was almost certainly silicosis (he was a heavy construction forman); it was not an easy death. It's hard to understand that things that don't hurt you immediately may come back to haunt you later. It's not the same as ghosts, because we can use science to measure and anticipate the effects.

Oops, I commented in  the wrong place.

Asbestos is nasty stuff when you dig into the research on it. I've torn off at least two roofs that I know contained asbestos in the assembly. One we just cut off the old membrane and the abatement company took care of the rest (tyvek suits, respirators, bagged all the debris). That one was for a junior college on their administration building. The other one was a small duplex and we found a label on the old tar paper that said "asphalt impregnated asbestos felt" and the date was from the 1950s I believe. Boss told us there were N95 masks (not adequate for asbestos BTW, see below) in the truck and that we should be very careful for the rest of the roof not to make a lot of dust or use the saw on anything. We'd already pulled off around 2/3rds of it already. Those are the ones I know of. I'm sure there were others that I wasn't aware of. I worry that it will come back to haunt me later. Hope your lungs don't diminish any more Wood Guy.

Radon is a gas from the Earth, pretty straight forward And as another commenter noted the second leading cause of lung cancer after nicotine. Asbestos is not so cut and dried. As a 9x9 floor tile which many of us see it's harmless as long as the tile isn't cracked. The adhesive holding it down has more issues with it. The dangerous stuff is the duct wraps and the pipe spray on products as well as the sprayed fireproofing that was used in a lot of schools. This is what's known as friable or disintegratable easily inhaled. Every once in a while I see an old advertisement for a company called Raybestos which made brake pads out of asbestos. There are probably a lot of traffic cops and street cleaners in the old days who are now mesothelioma patients who had to stand outside and breathe in all those fibers off those brake pads.

Brake pads are still allowed to be made from asbestos in the US, and many are.

AFAIK there is nothing that regulates the use of asbestos in the US. You could still make your duct liner and all those other things from asbestos. The thing stopping it is not a law or regulation but fear of liability. Regulation through litigation.

In the same boat as wood guy, cavalier in my 20s, saved bosses/clients money, didn't get paid more. Reduced lung function now, very careful about what I get into now. We'll see how my lungs are in my 60s. Father is in stage 4 lung cancer as we speak, not looking good. He did it all his life and also smoked.

Great article, Wood Guy! Thank you. I love seeing a diagram of how this is supposed to work.

I concur. I like your article Wood Guy. It is really useful. Thanks.

The 4piC/l is arbitrary. There is no data to say conclusively 5 will kill you but 4 will not. In fact all the health physics data is totally scattered up to a very high radiation exposure.
Your clothes and skin are sufficient to shield you from the alpha particles. Only
living lung tissue can be damaged. The best data comes from miners who worked in 1000+ piC/l. If you are say above 25 piC/l then you might consider dropping the $2500-3000 on a mitigating contractor Otherwise you are fine.

Welp, thanks Thayer, there goes the rest of my workday....

This is a radiation-based issue that you can not completely and 100% eliminate as that is scientifically impossible. We can eliminate the unacceptable health risk hazard by methods where the radiation levels and radon gas concentration is kept consistently at acceptable levels. There is a reason why the term 'radon mitigation' is used not radon elimination. The idea is to bring the radiation levels and quantity of radon gas concentration down to acceptable levels. Radon barriers do help but ventilation is another key part of the solution. 

There are multiple levels of radon mitigation. There is no such thing as radon elimination, in a scientifically true sense. The cheapest solution is the lowest level of mitigation. The $2K solution is a start but a good solution is not necessarily going to be the lowest bidder's approach. I back Everyday Architect on a more comprehensive solution to addressing the radon issue than the cheapest solution that maybe done to reduce risk but there is also a trade-off of how much you invest in addressing the radon issue when there maybe other issues as well to address. Don't over focus on addressing radon if there are other important issues to address when you have limited financial resources. Tackle the biggest issues. In an ideal world, every home would be safer than any hospital today.

The decaying radon is just an atom. And we're all made of atoms so it must be safe. I am very smart.

technically it's not even giving you cancer it's just moving electrons around and reorganizing chemical bonds. if your dna can't tolerate a little instability maybe you're just the kind of person with lousy dna who gets cancer for no reason anyway.

All radiation can cause cancer at a high enough level of radiation. When the radiation level is low enough for the type of radiation, your body can take it. If too high, bad shit happens. Even old fashion AM/FM band radio can cause problems like cancer. Exposure is the key factor and so is the type of radiation a factor. Cancer is a negative bodily response to radiation (and other causes).

You are correct that DNA can handle a little instability but the DNA of each type of life form is not equal. Some life forms have much stronger DNA when it comes to high radiation exposure. Humans are not one of those life forms. Our DNA is delicate. Our DNA is developed to handle the average radiation environment of Earth since human race began. Earth's magnetosphere shields us from a lot of the radiation found in space at much higher levels. This is why all manned space missions have been inside the magnetosphere of Earth. Cancer is the most common form of bio-chemical reorganization from excessively high radioactive exposure.

The reason we have skin is for radiation but our skin is not resistant to very high level of radiation but normally radiation from the sun that passes through the atmosphere and normal ambient radiation in an open outdoor environment. We never developed a 'skin' capable of shielding us from higher levels of radiation. 

You are correct that radiation from radon doesn't "give" you cancer but that cancer is a biological response to radiation. I don't call that a good type of biological response.

/\ you can't be serious? I got a fungus for that -Radiotrophic fungus

Do you realize that light and radio are EMR? Seriously, don't be a douche on regarding this topic matter.

put down that cell phone!

focus!

I've heard, side effect of Radon, seeing Brad Pitt (however you like to see him)...just sayin'

I just want to cover all my bases here. I did click thumbs up by accident first on Donna's post, then had an ohhh! shit moment - whuuut - I like a dude from Springfield Missouri! fuck that, I'm north of I-70...Coach (hired revolutinoary   war dudes that were german=name), he partied with Pitt (supposedly) so I quickly did the thumbs down...total mistake, just sayin'.

Let’s talk today! After I’ve had my coffee tho...

Glad to hear it. I was going to mention encapsulation and alternative options. In Atlanta we get a lot of high radon counts due to all the granite, or so we're told, but it's really hit or miss location wise. Since most have a partial basement crawlspace thing at best, usually the solution is at the joist framing, encapsulation foam and a new floor. Then just don't go into the vented crawl. We're more concerned about the actual type and thickness of foam and preventing wood rot due to humidity levels in GA. Often the cost to encapsulate to create some occupiable basement space is just not cost effective.

Insulation also helps a lot, as it keeps the warm, moist air from condensing on the cool masonry surfaces where it provides mold and fungus with moisture. (It has to be the right type of insulation, of course.)

Try this. Set one tester outside for 48 hours. It may read up to 2 -3 piC/l. Also the measurement devices are only required to be 25% accurate, yes 25%! You really need to be 25 piC/l
higher to even consider dropping $3k

I'd say very close, considering the "oil spill" that resulted.

I didn't meet with the contractor, my husband did.

let me guess... you sell radon detection devices?

up to 6 bays is ok. no testing required but it's pretty damn important to test for if you have 7 or more bays

Depends on your location. Here in GJ it's only 4 bays. Then again, we did have a radium mine somewhere around here . . .

The benzene fumes will probably kill you before the radon does.