Radon experts?

[Indianawood]

Idea's on Radon mitigation. I bought a digital tester and readings currently are about 14.
House built in 2003. Full basement partially finished. Walk out on one side. Poured walls, concrete floor.
Questions
Most of my basement floor is still unfinished. Would caulking all the cut lines and the few cracks help?
I have a bk king in basement. Would disconnecting the OAK help or hurt?
Any ideas appreciated

 

[superking_]

Sealing the cut lines may help. Don't think disconnecting the OAK would have an effect. Strongly recommend a proper mitigation system. Safe levels are below 4. If you already have a sump pump they can sometimes use the same pit for the radon system.

 

[Indianawood]

Sealing the cut lines may help. Don't think disconnecting the OAK would have an effect. Strongly recommend a proper mitigation system. Safe levels are below 4. If you already have a sump pump they can sometimes use the same pit for the radon system.

I do have a sump pit. Currently sealed and unused. Never had a water problem. Is the caulking worth trying? Will the mitigation blower mess with my draft on bk?

 

[moresnow]

Unhooking the OAK would likely be going backwards ln your situation. Possibly think about a cheap/quick DIY mitigation system as a experiment. Should be able to find some examples if you google etc.

 

[Indianawood]

Unhooking the OAK would likely be going backwards ln your situation. Possibly think about a cheap/quick DIY mitigation system as a experiment. Should be able to find some examples if you google etc.

I could easily install a fan ducted unit in my sump myself. Was just trying to avoid that by possibly sealing instead. There are lots of cut lines in the floor i could seal. Just wanting to make sure its worth trying

 

[moresnow]

I could easily install a fan ducted unit in my sump myself. Was just trying to avoid that by possibly sealing instead. There are lots of cut lines in the floor i could seal. Just wanting to make sure its worth trying

Call a radon pro for a consultation. Perhaps?

 

[Indianawood]

Call a radon pro for a consultation. Perhaps?

I could install a mitigation system myself for what they want to consult. Just wondering what people have tried that may or may not have helped

 

[John Galt]

If you have an OAK on the King, radon is likely being pulled in from a stack effect. Sealing every crack in the slab and the walls will help but may not get you down far enough. It's a great place to start. I'm not an expert but have done lots of reading and designing for my house.

 

[Indianawood]

If you have an OAK on the King, radon is likely being pulled in from a stack effect. Sealing every crack in the slab and the walls will help but may not get you down far enough. It's a great place to start. I'm not an expert but have done lots of reading and designing for my house.

Would disconnecting the OAK help or hurt?

 

[John Galt]

It would hurt. Disconnecting would cause more air from the inside to be drafted out and creating more negative pressure in the basement. There are a few make up air devices on the market, the simplest cuts a hole in the wall and has a pipe with a filter. You'll need to create a negative pressure under the slab to keep the radon from coming inside or have a balanced system inside so the radon doesn't get pulled into the basement.

 

[kennyp2339]

First things first, pay for a real radon test with a true calibrated instrument, you used yours, it gave you the indication that there was the possibility of something wrong, now get the real test to confirm it then think of remediation.

 

[Indianawood]

First things first, pay for a real radon test with a true calibrated instrument, you used yours, it gave you the indication that there was the possibility of something wrong, now get the real test to confirm it then think of remediation.

Here's what im using

 

[peakbagger]

I am not a radon expert but I will use common sense obtained by researching it over the years. First thing to do is make sure you are dealing with the correct problem. Radon comes from three typical sources. It can come into the house dissolved in the water, come up from the soil under the house and on occasion comes with masonry materials used to build the house. Radon is heavier than air and will eventually pool in the basement. Radon from the soil gets sucked into the basement as the basement is at lower pressure than the soil as the house is generally lower pressure than the soil. Radon that comes with the masonry (aggregate in the concrete) will slowly leak into the basement so its dealt with like radon coming in with the water unless the water is scrubbed with blower system or charcoal filter system.

If the radon is coming in from the soil, you have to create a lower pressure area with air flow under the slab. If the house was built for future radon mitigation or you were lucky there is a layer of crushed rock under the slab. By sealing up the floor and installing radon fans ducted to the roof you can create that lower pressure area under the floor with a fairly small set of fans . if the floor has lots of cracks, a sump pit that is not sealed , open floor drains or "tight soli" then you need more fans spread out over the floor. A combustion source with chimney or stove pipe increases the pressure differential compared to a house without one so an OAK is in theory reducing the pressure difference slightly between the basement and the area under the slab so its net improvement.

Its pretty rare if there is subsurface radon source that it can be sealed out without subsurface depressurization. Contractors tend to go overkill but beyond dealing with the major leaks you really need fans.

 

[Corey]

I'd definitely say get a second opinion. Bare minimum, put your detector in a space where radon would be expected near zero (above ground, outdoors, fresh air, garage, shed, attic, etc) and see what it says. Assuming we're talking picocuries/L (pCi/L) long term average? I think the EPA action level is 4 pCi/L, you are reporting 14 - so that is more in the 'tear down the house and open up the uranium mine' level. OK - maybe not so drastic, but definitely worthy of a second opinion / cross check. Also, be sure the detector is not near any natural sources of radiation... granite, concrete, metal, fluorescent lights, dinnerware / clay / ceramic items, bananas, brazil nuts, camping lanterns, anything with a glowing dial/face, smoke detectors, etc.

Guess I could see the OAK as helping or hurting:

With the OAK, you're bringing in outside air for combustion, so no net air changes in the house, and you're not 'pulling radon in'. Though this could be allowing radon to build up naturally by leaking through cracks, pipes, sump pump, etc.

If you do away with the OAK, you will pull a slight negative pressure, but a burning stove will exchange all the air in a decent sized room every few hours. So if that negative pressure is met by some non-radon source, (slight leaks at windows, doors, etc) and the basement floor is essentially sealed, you could actually be 'freshening' the air. Though if the negative pressure is met by cracks in the basement floor, it could be pulling in even more radon.

 

[kennyp2339]

Oh man, my post seemed rather direct and intense, sorry dude.

 

[Indianawood]

I am not a radon expert but I will use common sense obtained by researching it over the years. First thing to do is make sure you are dealing with the correct problem. Radon comes from three typical sources. It can come into the house dissolved in the water, come up from the soil under the house and on occasion comes with masonry materials used to build the house. Radon is heavier than air and will eventually pool in the basement. Radon from the soil gets sucked into the basement as the basement is at lower pressure than the soil as the house is generally lower pressure than the soil. Radon that comes with the masonry (aggregate in the concrete) will slowly leak into the basement so its dealt with like radon coming in with the water unless the water is scrubbed with blower system or charcoal filter system.

If the radon is coming in from the soil, you have to create a lower pressure area with air flow under the slab. If the house was built for future radon mitigation or you were lucky there is a layer of crushed rock under the slab. By sealing up the floor and installing radon fans ducted to the roof you can create that lower pressure area under the floor with a fairly small set of fans . if the floor has lots of cracks, a sump pit that is not sealed , open floor drains or "tight soli" then you need more fans spread out over the floor. A combustion source with chimney or stove pipe increases the pressure differential compared to a house without one so an OAK is in theory reducing the pressure difference slightly between the basement and the area under the slab so its net improvement.

Its pretty rare if there is subsurface radon source that it can be sealed out without subsurface depressurization. Contractors tend to go overkill but beyond dealing with the major leaks you really need fans.

I would think this is a good place to start. Pretty big cut line and cracks. There are not many cracks but lots of cut lines. The walls are poured and membrane so id think those are less likely the culprit

 

[Bad LP]

The very first thing to do is seal the expansion joints and the wall/slab corner. Include any and all cracks.

 

[m159267]

House built in 2004. Our basements sound identical. Using the identical tester you have I found our radon levels to be 18 and higher. I did not hesitate - I researched radon mitigation companies and had a mitigation system put in. Our long term average now fluctuate between .25 and .45. BTW - the mitigation company radon tests show our tester to be spot on. Also I have a pellet stove in the basement with an oak - it had/has no impact on the radon levels. Keep in mind when you sell your house radon levels will be tested.

 

[Indianawood]

House built in 2004. Our basements sound identical. Using the identical tester you have I found our radon levels to be 18 and higher. I did not hesitate - I researched radon mitigation companies and had a mitigation system put in. Our long term average now fluctuate between .25 and .45. BTW - the mitigation company radon tests show our tester to be spot on. Also I have a pellet stove in the basement with an oak - it had/has no impact on the radon levels. Keep in mind when you sell your house radon levels will be tested.

What did they do to get you to that level?

 

[semipro]

The very first thing to do is seal the expansion joints and the wall/slab corner. Include any and all cracks.

2nd this. ^
Our levels were about 7 pCi/L
Sealing all the cracks and penetrations in our basement foundation with a self-leveling concrete sealant brought our levels down below 4.
We have a pellet stove in the basement fed by outside air.

 

[m159267]

What did they do to get you to that level?

They installed a typical mitigation system (pics). Cost was approx. 1500.00. Yup costly. But when I sell it will be no problem.

 

[Indianawood]

Update. We are working on sealing all cracks.
While sealing i pulled the lid on what I thought was a sump pump pit. I now remember when we built the house this is not a sump pit but a pre plumbed lift station pit for a future basement bathroom. I assume that will not work as a radon pump station? Its plastic lined.
We do have perimeter drain tile around they entire foundation that exits both corners of the walk out side of the basement. Currently they are buried where they terminate.
1. Would opening those up to the surface help?
2. If sealing doesn't fix the problem could a mitigation system be hooked to those?
They are slotted 4" drainage tile with rocks(peagravel)around them
We don't have a sump pit and have never had any water issues

 

[carg3]

I'm afraid sealing your cut lines does nothing for you. The saw is generally set for 1/2" to 1" depth. You still have, in most cases, three or more inches of concrete below that. Your sump pit may be the culprit. Is it a stone bottom? In most cases, the inside of the footers, in other words your basement, gets filled with stone. Then the floor is poured. In our part of the country, a vapor barrier is required. So the sump pit is the only point where you are currently exposed to the soil beneath the house.

 

[Indianawood]

I'm afraid sealing your cut lines does nothing for you. The saw is generally set for 1/2" to 1" depth. You still have, in most cases, three or more inches of concrete below that. Your sump pit may be the culprit. Is it a stone bottom? In most cases, the inside of the footers, in other words your basement, gets filled with stone. Then the floor is poured. In our part of the country, a vapor barrier is required. So the sump pit is the only point where you are currently exposed to the soil beneath the house.

No sump pit. Sewage lift station pit. Plastic tub lined. Many of the cut lines crack deeper, as intended. I suspect some all the way though

 

[Indianawood]

Perimeter drainage tile. One on each side