IamA Radon Mitigation Technician. Ask me absolutely anything.

Seriously, how bad is radon and does it warrant all the work people do to mitigate it with vent systems and such? If I don't detect it today, could tomorrow it just start making its way into my house?

I remember overhearing a supposed story a long time ago where some idiot was selling their house and put the detector in a plastic bag until the inspector came back. Thus the house was "clean" and they could sell the house without having to incur charges to fix the radon issue if there was one.

I've heard that story too. It's a lie. Any home inspector who is not just a scam artist will have a tamper evident test system and will seek legal damages against any client who tampers with such units.

Secondly, the systems cost very little compared to what else you've done to sell the house. saving a few hundred bucks is not worth openning yourself up to the legal trouble.

Radon is massive health hazard. I'm not trying to sell you on it, but it's one of the leading causes of lung cancer second only to tobacco smoke(and will overtake smoking soon in annual cases). Trust the scientific experts.

Radon won't just pop up in your house. It takes time and entry points. But if you have renovated at all since the last time(as little as painting even) get a test kit.

Now you have me curious - why painting and what of? Sealing the basement walls/floor with new paint or ???

The EPA recommends retesting after every renovation no matter how small. Usually with painting it is block walls. The super porous "leaky" blocks need sealed with something like a solvent based concrete paint or radon from the dirt surrounding your basement may leak and you might have to have a block wall depressurization system installed. There is also the threat of emanation from building materials, however outside of Sweden that is low.

How often do you think that residential home owners are convinced to mitigate a radon problem that doesn't really exist?

At least in my area, it's common for a home-buyer to try to get someone selling their home to eat the cost of installation (even in cases where the tests are marginal).

Very rarely. There is no "safe" level of radon. The cost of an installation is amazingly marginal compared to other home improvements(I've even done installs as cheap as $400 usd).

I have never mitigated a house under the EPA's action level of 4.0 pCi/L.

my check engine light is on, what's going on with my car?

Check your windshield wipers and your fluids.

If you have the last seat on the bus, and a pregnant lady comes on, are you the first guy to offer up your seat?

God no. Going up and down ladders all day strains the knees something fierce. Let one of the other lazy slobs on the bus stand.

What is the highest pre-mitigation radon level of a home you have worked on? What did mitigation bring it down to?

210 pCi/L. They lost several dogs and cats to lung cancer and didn't bother getting it checked until both of the homeowners developed it as well. I greeted them behind a scuba mask. My initial subslab depressurization brought it down to 70 pCi/L. So I added several more collection points and added a stronger fan. and now it's down to under 4.0.

I've a home that tested at a 7.0 but our inspector basically told us that it was no big deal and not something to be worried about.

Is spending extra time in the basement bound to be more exposure than spending extra time on the second floor by any measurable degree?

What are the common mitigation options?

There are four options. A passive mitigation system(which I DO NOT suggest), active depressurization system(which I do suggest), a ventilation system(which is more costly), and an active pressurization system(which is only done when active depressurization is not an option).

The way homes are built now, or any with an HVAC system newer than the 60's, you're going to be breathing in that air as it cycles through.

I would seriously suggest you make sure the inspector was properly certified and do a second test(which the RMS requires after ANY test higher than 4.0).

I have a radon mitigation system in my house. Its a large pipe that goes from the foundation in the basement to the roof with a fan in it. The sump pump was sealed. I had to remove the seal to install a new, larger sump pump because the old one stopped working. What should I do? Do I need to reseal the sump pump somehow? If so, how?

Silicone caulk around every perforation and between the cover and the basement floor. Go heavy and smooth it out after everything is covered.

Hello, thank you for educating the us. My fiancee and I are looking at buying a house and would like to know as much about problems a house could have before we buy it. I thought I knew about radon, but now that I recall it's all hearsay. Would you be able to correct what I think I know about radon and please teach me where my understanding is not complete?
Here's what I think I know: Radon is naturally occurring radiation from the earth. It seeps into basements and is undetectable with our senses. A simple system of fans or constant airflow through the basement can move the radiation outside making the basement of your house safe. Am I on track?

You've got the broad stroke of it. I suggest checking out the Home Buyers guide to Radon. Put out by the EPA.

I bought a house a while back and did not have a radon test done.

I ended up moving in with my gf less than three years after that purchase and sold the house (for a small profit!). The buyer had a radon test performed and it found the need to install a mitigation system. It makes me wonder what sort of ill health effects I might have suffered if I had stayed in that house for decades...

I will definitely be doing radon testing for any future home purchases.

What was the level? Anything over a 4.0 is equivalent to smoking half a packet of cigarettes per day.

I have an active radon mitigation system installed in my house. (No crawlspace- the pipe is connected to the lid of my sump pit.) I'm thinking of installing a fan to provide ventilation for my basement in general, since it can get a little stuffy in there. (I have a couple of small windows near the top of the basement.) But I'm worried if the fan is sucking air out of the basement, that will negate the suction of the radon system and pull the radon up from underneath my house. And if the fan is blowing IN to the basement, that will result in the radon that does make it into the basement being blown up the stairs and into the house itself... how does one ventilate a basement without interfering with an active radon mitigation system?

If the sump is properly sealed and remains as such, you have nothing to worry about. No fan or system you buy with negate the pull on your RRS. JUST MAKE SURE YOUR LID IS SEALED.

That's a really big issue in general(can cause certain appliances to backdraft gas into your house which will kill you far faster than radon).

The lid is sealed, but the basement was finished before the radon mitigation system was installed, so there are almost certainly some unsealed cracks hidden behind sheetrock or under the carpet.

Install a gas/carbon monoxide monitor in your basement. Do you have the manometer visible on your system?

Yes, I can see it.

Then install your system and check the manometer to see if there is a pressure change. If there isn't you can surmise that your fan is not effecting the active system.

What are your thoughts on the extensive amount of scientific research that says the entire thing is a scam perpetuated by our political system for monetary profit? In fact the Health Physics Society at the University of Michigan says the health risks are either too small to be observed or non-existent.

Vaccines don't cause autism. Politicians don't get lobbied by any industry body. So no, that research is wrong.

I am in a lovely zone 1 county. My basement floor has large enough cracks that water will drain out of my basement. Could my old furnace in the basement spread radon through out my house?

Seal the cracks and get a french drain or similar, or even just call a basement waterproofing company. And yes your furnace can.

Opinion on Mallow Ireland? Highest levels of radon in the world

I'd love to work there but the Irish have some nutty standards. Any place that lets you vent the air at grade is a place that will have some bad cancer numbers.

Tell me more about the standards, I live here

It's my understanding that in Ireland, and most of Europe, the gas vents are all placed at grade(on the ground) and the fan is inside the thermal pocket of your house. Which is terrible as both can increase your radon exposure.

Yes the vent in my house is like 25cm off the floor

Check your local building codes. That's a little concerning.

Radon and Granite counter tops. Comments?

If you can get a different counter top. Anything that screws with radioactive material testing is a big no for me.

If the granite is located at a different level than the basement, will it still throw it off? And does it usually screw with the testing in a way that makes the house test higher or lower?

Normally granite will only throw off tests left on the granite themselves, but don't take chances and just keep it away.

If there is enough radon in one's house to be harmful, can its radiation be picked up with a Geiger counter, or does it have to be detected chemically (probably not easy as it's a noble gas?)

Depending on the counter used, yes. And it can be picked up chemically with fairly decent accuracy using liquid scintillation charcoal and activated charcoal tests.

Boxers or briefs?

Free ball.

If I live in an apartment on the building's lowest level, should I get a kit for testing? Or this something that landlords generally test in accordance with local renter's laws?

Your landlord likely does not test. You might want to check with them about whether they do or not.

I live in Las Vegas and have no basement. Do I need to worry about radon?

Nobody needs to worry. Every home is at risk and you may want to test.

How did you get into this field? Any specialized education/certification?

I got hired in with no existing degree or training. I am certified through the NRPP but that happened about two months after I got working.

I have a Radon Mitigation system in my house on one side of my basement. It is a pipe from below to a fan blowing on my roof. Is this certain to eliminate the radon in my entire house? I wonder if the other side of my basement may still have radon.

A subslab depressurization system is 99.99999999-% effective at reducing radon in the home's air. If your basement has multiple footers, different foundations, or areas with sharp elevations, you may want to have a certified professional do a communication test and a pressure field extension test.

Have you ever cheated on your wife?

I'm not married. But if I was I would not.

Does basement temp/humidity increase/decrease radon levels?

If it is enough to effect the air pressure inside the home, yes. But so does every area of the house.

When I bought my house I tested at 3.1. A more recent test measures 2.1. I understand that this is below the EPA's action level, but I'd like to do some light mitigation regardless. My sump pit can be sealed and I have a basement window right above it that I think would be a good place for a fan.

Do you have any recommendations on a DIY set up for this?

I appreciate your time an expertise!

Seal the sump with some basic silicone caulk. but leave yourself a window to check to ensure your sump is still working. Do that by jigsawing a 4" hole and sealing it over with 5" of 6 mil thick clear poly/painters plastic. I don't suggest ventilating except during the times when you'll be down there. Remember though that neither of these are "mitigation" but prevention. And ventillation alone can increase the pressure differential and raw more radon into the house.

I actually work for a company that manufactures radon monitors, What type of devices are you using to detect the radon?

I use the Air Chek activated charcoal test kits.

My house was unoccupied for several years (5+) and then sparingly for 2-3 months out of the year before that. Before we bought the house, we found it had levels of 21pCi/L. Could this high of level be from lack of airflow in the house since nobody was living there?

Also, we are renovating some things...should I wait until after renovations are complete to work on getting a mitigation system installed? Once installed, do I still need to retest after every renovation?

Finally, what is the typical cost of a system that you install and what factors will make it more or less costly?

This is a common misconception. But no, the house being closed up won't really effect the outcome of the test(it can but it's not a significant amount). By all means, retest if you have any doubts.

Once installed you must retest after every renovation. But nobody is going to come in and ask for a record of your results. so a single test done after all the renovations would be acceptable to any potential buyers.

I would highly suggest having the system installed before your renovations are finished. It's much easier and cheaper to have a carpenter or electrician provide services, such as boxing the system in, when they're there than waiting until they're gone and dealing with it after.

Systems cost anywhere from 700(if you have an existing passive system) to 4000(if you have well water that needs treated). Budget out 1500(the high end of standard systems) and haggle. The less work I do the less you'll pay.

Any idea what this thing is? Moved into older house a few months ago. It's in one of the basement windows. Is it just a regular vent of some sort or could it be someone's idea of a radon vent? The pvc pipe runs over down into the sump hole. We tested below level of concern at inspection. It's never been plugged in. The hand-written markings on the dial make me curious because they're not like 'high, low, off'. There is otherwise no ventilation in basement. Thanks!

Looks like an old E/HRV. Take it apart and see.

Nothing even comes up when I first google that. Do you mind explaining what an E/HRV is and what it means? Thanks!

Try Energy Recovery Ventilator. The E/HRV is Energy/Heat.

Is there any way to make the mitigation system more attractive? I live in a house from 1925 and am not excited to have a giant PVC pipe jutting up, around and over my roof.

Paint the pipe, or see if the installer will use something like gutter downspout.

Mine's built in 1927... poured foundation walls solid floor, no sump. Walls sealed with drylock maybe 13 years back. Only hole in the basement floor is the drain to the sewer. I've read a lot about folks with crawlspaces, sump pumps, etc... but what about a (mostly) sealed basement?

You never know unless you test. But a lot of the basements I go into are completely sealed.

Are there any inexpensive tests I can use at home to test it myself?

I bought a house a couple years ago. The radon was a little high initially and a mitigation system was installed. After they installed it, they left a little metal puck that I was supposed to mail in to make sure it worked. I never did mail it in and I've done some renovations since then, so I'm thinking a retest might be smart.

There are a few cheap ones. I suggest calling a radon mitigation company and seeing if they'll send you one for free or at cost.

Background:

I bought a house last year and by requirement, all houses built since 2000 in my new city have to have a passive radon system installed (Midwest, and we are apparently over a huge uranium deposit). I wanted a radon check regardless and it was like 14 pCi/L, so i had them install an active system. As part of this, they completely sealed my sump pump in with a clear silicone.

Questions

1. Is this normal? I cannot access my pump for maintenance if necessary without cutting off a half inch layer of silicone, and then I presume I have to replace this layer and test again to ensure it is resealed?

2. I have started to develop some cracks in my basement floor. Most are hairline, but some are as large as 3mm in width (I cannot gauge depth). Should I be concerned about Radon resurfacing in my basement or should I not care unless I see my pressure gauge indicate loss of pressure?

3. My previous neighbors before I moved had a 46 pCi/L, how does that compare to what you have seen? They told me the mitigation specialist who was installing their system flipped shit when they told him the values as he had been working without a mask since he didn't know how bad it was prior (they apparently had a crack in their floor almost an inch wide). He compared it to smoking 2 packs of cigarettes a day type of exposure on the lungs.

1. It's normal. And yes.
2. If you can't see dirt don't worry. But feel free to seal those cracks.
3. That's about right. You never know how a home will test compared to the neighbors. And the tech was about right in his assessment. I always ask the level before I enter a home.

Our radon system is quite noisy and prone to doing the "wow" thing where the vibrations go in and out of sync in some sort of sympathetic vibration pulsing. What's the best way to mitigate this noise and make the system quieter?

Place significant insulation between the pipe and the wood. Besides that call the installer back and see if they have a way to quiet it down.

Thanks for doing this!

My husband and I are buying a home and the house tested at about 5.5.

The seller is putting a mitigation system in, but out of curiosity, on a scale of healthy to ass cancer, how bad is that? What's the highest number you've seen?

Also, half the basement is finished, should we get a test done in the finished area as well?

Anything above a 4.0 is about half a pack per day and then increases every 6-10 from there another half. It's not bad but I would suggest mitigating. I've seen numbers in the 300's but the highest I've been in is 210 pCi/L.

And no, one test in the unfinished area is sufficient.

There's a good deal of scientific literature out there that basically says radon mitigation is a scam, and that indoor radon does not pose a significant safety risk. How do you respond?

Anyone who says it is a scam disagrees with the EPA, the WHO, the CDC, all European medical bodies, the AMA, the ACA, and literally thousands of scientists. It's like people who oppose vaccines.

So you believe the scientific studies from the 90s that found no correlation, or even an inverse correlation, between indoor radon and lung cancer are illegitimate? Can you point to some actual scientific sources, not just conclusory but with data, that you believe support the idea that radon causes lung cancer?

There was a study in the 90's that "conclusively" proved vaccines cause autism in healthy people. Will the CDC work? http://www.cdc.gov/nceh/radiation/brochure/profile_radon.htm

Fair point on vaccines and autism. But One problem some people have with the EPA and CDC's information is that it lacks any source data. All you get are conclusory statements that "radon is bad." The scientific literature that says radon is a scam is backed up with actual data.

Which scientific literature? Because the EPA sources every claim they make in everything they put out.

I scheduled my abatement during the Radon awareness month for this April. Our basement tested higher than what my wife and I were thrilled to see so that's why we took the plunge. If I was more aware of Radon I would have tested it going into the purchase process of my house.

Do you think Radon testing should be mandatory for any buy/sell situation? Also, do you perform abatement for businesses as well?

Thanks for the AMA!

I do commercial work about once a month. I don't personally believe that testing should be mandatory. However, a home inspection should be and every home inspector should test.

Any suggestions on fan noise? We've got a radon mitigation system - the pipe comes up from the basement through a closet and there is a fan in the attic. Especially at night you can hear the constant hum of the fan (not sure if it is vibration off the pipe or the fan itself) which can be a bit annoying.

Insulate around the fan and anywhere pipe touches wood. Besides that you may want to see about changing the fan.

Hi there,

I didn't know what Radon was until I searched it up and it turns out that I live in an area of Canada that is pretty saturated with it.

I looked at a diagram of points of entry, and it showed basements and basement windows.

Is it dangerous to keep basement windows open for long periods of time? My bedroom was in a basement for about 10 years and I almost always had the window cracked so it didn't get stuffy. Now my younger brother has that same room and I may be moving back home into the other basement bedroom. Do you think it will be a problem?

How come the public isn't made more aware of these things?

Whenever anybody makes money you get tinfoil people coming out the woodwork to debate them. My own parents thought it was a scam and delayed their own system.

I do strongly urge you test that basement and if over 4.0 pCi/L get some mitigation. But systems up there vent at grade so see if the tech will take it above the roof.

Would you recommend a self-testing kit or having someone come in and do the test?

I've found a self-testing kit I could have mailed to me and it says we would need to leave it for 91 days before sending it back.

Would having a technician come in give us immediate results?

The self test is just fine. Getting a technician does not get you immediate results. All testing devices I am aware of require at least a day.

Has constant exposure to radon given you any super powers? Conversely, has it had any detrimental effects, such as making your hair fall out or making you grow a third testicle?

I have not noticed anything, no.

In a fight between Radon and Mothra, who would win?

Godzilla.

What's the most traumatizing experience you had with turtles as a child?

Never experienced turtles in person.

What do you do in your spare time?

I listen to audio books and masturbate to pornography when I'm not working or trying to find love.

Is radon the reason why houses in L.A. never have basements?

No. Cheap builders and faulty sewage lines are.

I have been using an electronic detector like this.

It's been reading quite high - 400-500 or so Bq. I would like to get a different tester to just make sure it's accurate, but my area is known to be bad for Radon.

I have considered a sub-slab venting system, but I'd probably end up having to do it myself, and I'm not sure I want to go there.

What I think I'd like to do is go with an HRV (Heat Recovery Ventilator) as I'd been considering one anyway. I do also need to add make-up air (I have a wood stove, for one thing) which I realise is a separate issue.

What are your thoughts on an HRV as Radon mitigation?

HRVs are not effective at anything above 12.0 pCi/L(and I'm not sure about the conversion to BQ so). They are far more expensive than subslab systems too. I urge you to reconsider.

But always retest.

If I detect Radon, and I am renting, does my landlord have to take care of mitigation?

Depends on the local laws and your rental agreement. Ask a lawyer.

Our house has an active mitigation system. I am told by the daughter of the previous owner that her mom had it installed because she blamed radon rather than her chain smoking for her lung cancer, and so it may not have been necessary. I'm thinking of unplugging it and doing a test to see if the need is really legit, since the system is in the way of some renovations I'd like to do. How long do I need to wait after unplugging and before testing? If there is radon, will it need time to accumulate to some level to be detectable? Thanks!

I'd give it a week. But before you do realize that active depressurization a systems are designed to run continuously and pulling the plug may allow water to build up and short the fan or fill the pipe.

When my girlfriend and I had our new home inspected before purchase last spring, we had our inspector do a radon test. He got a result of 4.5 pCi/L, but said that he wasn't concerned because it had been raining for the past several days, and that we were probably under 4.0 in normal conditions.

Was he correct, or should we retest?

If there's any question: retest. But he was right. Storms change the air pressure and that draws Radon into the house.

Favorite pizza topping?

Pineapple.

If I have a pier and beam house do I still need to test for radon?

Yes.

Is this just an issue for people with basements? If a house is above ground could it have Radon?

Radon is an issue with every house and building no matter the foundation type.

I live in a double wide trailer, is radon an issue with these types of homes? It's not exactly touching the foundation yknow?

All houses with all types of foundation. I have mitigated trailers before.

Is frequently airing out the lower parts of the house at all useful in reducing the concentration of radon? Apparently radon is significantly denser than air and pools on the ground, so in theory shouldn't there be some benefit in opening the doors/windows every so often?

Depending on the air pressure you may be causing some stack effect infiltration. Ventilation in this manner is merely prevention and not mitigation however.

Where in the NE are you? PM me if you do work in SE Mass, our house tested at 7.2 a few years ago, and we're finally looking to get it mitigated.

I'm not in the North East. I suggest just googling "Radon Mitigation near me" and call the first few companies.

Do you have a basement? (I am genuinely curious, as that's where from memory radon builds up.

I do, and a sub basement. But every home, even those without basements, are at risk.

If there is a moderately high radon concentration in the well water (~4,000 pCi/L), would using a vaporizer in a closed room cause the radon in the air to become high?

The ratio of water to air radon infiltration is about 10,000 pCi/L in water = 1 pCi/L in the air. So no, you might cause a slight "spike" but it would be somewhat negligible.

Why not post this in /r/HomeImprovement ?

I may post there later. The main reason is that this is exposure. More users here, higher possibility of finding someone who has a question.

And in my opinion Radon Mitigation is not always pertinent to just the residential market. A lot of my work comes from commercial properties(hotels, dorms, and apartment complexes).

How common is Radon in Northern MN?

Are there pockets of Radon in like a Map format, or is Radon pretty much everywhere ?

In the US the EPA "grades" regions based on the likelihood and known concentration of radon. I don't know your specific area because I'm on the BEAST COAST, but do consider calling a radon mitigation and solicit a test kit from them. Here's the EPA's map

Can you predict anything about radon risk by the type of terrain the house is sitting on? According to the EPA map you linked, I'm in a Zone 3 county. But I do see some houses in the area with radon mitigation systems installed. Not many, but a few.

I'd love to say yes. Really. But no. There are some neighborhoods where every house has one and some where the system I'm installing is the first of it's kind. There's a lot of factors that go into radon infiltration many of which will actively change once a house becomes occupied. The best indicator, but is not by a longshot a definite, is home age. Older homes built before the aggregate code change(which varies by area) will often have much higher concentrations.

This house was built around 1960. Does that suggest anything?

You should likely get a test kit. Do you know what is under your basement floor?

No. The hill is I think primarily clay.

Well if you're curious go ahead and get a test kit. If nothing else it's just peace of mind.

I don't really know if it's worth it to be worried or not.

Well it's up to you. I will say this, it's better to know early than find out in the doctor's office. 4.0 is the EPA's action level. But WHO suggests 2.7. But I've been in houses over 200 pCi/L talking to people who, have had multiple pets die of cancer, say the same thing.

So what's the best way to get a home checked? Just find a company that will come out and test the home? What about houses that don't have a basement? Are they at risk too?

The current science says all homes are at risk. You can buy your own test kit at an home improvement stores. You can also call a mitigation company who will often send a free test kit. Or you can get a home inspection done by a certified and licensed radon measurement professional. I highly suggest getting an inspection once a decade. Codes change and roofs develop leaks and that's a great way to catch issues.

So when you install ventilation for radon mitigation what are you putting in , what is your target ventilation rate and how do you evaluate/confirm the results?

I do not install ventilation systems. They don't work to reduce radon levels over 10 pCi/L, they cost a lot more to run, and they require a lot more space.

The E/HRV systems that are the standard ventilation approach are a big mystery to me. We covered them for five minutes in my certification course and that was filled with a lot of reasons to never touch them.

As for evaluating the results, I leave a test kit at every job. The RMS requires that somebody test and NRPP takes a very negative view of everyone who returns to their jobs to run the tests/has deals with a tester. So hands off and the test goes to a third party lab just so no one can claim I'm lying.

Can you please give me the TLDR of what Radon is, should I be concerned, where do I find it, and what do you do?

what Radon is

Radioactive gas.

should I be concerned,

Well are you concerned about dying of lung or stomach cancer? relatively younger than your natural lifespan would suggest?

where do I find it

It's everywhere. But test in the lowest lived in level of your house.

what do you do

I install a system, usually a three inch pipe with a fan and more pipe going over your roofline about two feet.

Thanks for the reply! Realistically speaking, is this system actually recommended? Where does the gas come from and what can you do to minimize it?

The subslab depressurization system is the most successful radon reduction system. The gas comes from the decay of radioactive materials in the soil(and other sources). What I do is I install a system that creates a pressure field and draws the radon out.

I just had a Radon test done with a Radalink device over a 2 day period. The average reading was 1.3 pCi/L. How does having a forced air heating system affect the results?

As long as the test was placed within compliance to the RMS testing procedure, it wouldn't effect it at all.

If the device was immediately under a heat duct, I would expect it to be higher.

When going to test for radon are you exposed to it? or what measures do you take to mitigate exposure?

I am exposed, normally. However when working in a house over 30 pCi/L OSHA requires I wear a respirator. In environments over 100 I wear what amounts to scuba equipment. Besides that I keep track of my "working level months" and take a small vacation when it gets close to the standard cut off.

Hi I am a surveyor in training, I learnt about natural radon deposits in the earth (In the UK), I have two questions regarding this, how does it get their and without technical equipment can you detect it easily?

Essentially radon "Gets there" by being there. It's a decay product. Radon is invisible to our senses and we have to use either test kits or a variety of electronic testing devices.

How old were you when you lost your virginity, and do you regret it?

16 and no.

Who was the lucky guy?

Your father.

daddy?

You know what he likes to be called while getting railed?