I have 100 year old Maryland rubble stone basement with second lower addition basement from 70s. I put radon fan on lower addition sump pit but radon levels persistent 10-20 pci/v. How do you know where to drill the sub slab holes when there is only dirt under the slab? And how do you know they will be effective? Does it require a higher wattage fan for for slabs with soil underneath? There is so little info on these types of basements. It's truly an art. The local radon guy would not even work on it because he was afraid of causing structural instability.
Are both of your basement floors concrete? If not, the floors need to be sealed from the basement air. You are correct, there are different strength fans for different sub-slab-soil types. But the stronger you go, the more you need to test that the air is coming from under the slab, and not the conditioned air from the basement/house (you can test with a smoke pen/device all around to see how much air is being sucked and where). Leading into your question on how to test if the suction is adequate in all locations under the slab. There's a tool that you can get to hook hoses up into and it will tell you the suction in various locations...I think it's a digital handhelt Manometer. You drill some small holes in multiple places around your basement, start sucking from you main location (with a shotback or radon system), then you will see if the suction is strong enough in all those locations. If the suction is not strong enough because of your soil type, you can drill 4 inch holes in the form of a line, separated by a foot or so, and dig up the dirt under the slab, creating a channel for the air to get to the suction point. Then seal the holes with concrete and caulk. Because of the rubble stone walls...you really will be in the best situation if you talk to a professional radon mitigator. That can be complicated especially if you have water running through the stone. You can spray with something like gunite...but it should be professionally done. If all floors are concrete, I would probably do the sub slab mitigation myself via that digging technique until suction is good enough under the both slabs, then make sure that everything from the footer up is 100% sealed. If radon persists, I'd talk to somebody about sealing the walls.
Also note that if you have low-none gravel content under the slabs, most of your air-draw will be from the perimeter of the house. (unless you do the drilling technique)
The radon mitigation specialist that is looking at the home we are trying to buy said he needs to do a core sample to see if he can get pressure for a pump. The house was built in 1905. He also said he may not be able to install a pump because the old house might have a footer in the basement. Is there a solution for this?
i live in an older house with dirt below the concrete floor in the basement. i dont see any crushed gravel. with midigation systems still work in this scenario?
trying to figure that out as well. it is reccomdned for some old homes you just have the basement windows open with a fan in and fan out, but that would get cold in winter
@DavidB-j3p just so you know i went ahead and had a midigation system installed anyways on top of dirt. we dug out 5gallon bucket worth of dirt and installed a fan and the results were amazing. im in canada so my radon was over 600bq/ cubic meter and now my readings are less than 50bq!
What is the risk to workers, being in an environment with the highest concentrations of Radon on a regular basis?
I have 100 year old Maryland rubble stone basement with second lower addition basement from 70s. I put radon fan on lower addition sump pit but radon levels persistent 10-20 pci/v. How do you know where to drill the sub slab holes when there is only dirt under the slab? And how do you know they will be effective? Does it require a higher wattage fan for for slabs with soil underneath? There is so little info on these types of basements. It's truly an art. The local radon guy would not even work on it because he was afraid of causing structural instability.
Are both of your basement floors concrete? If not, the floors need to be sealed from the basement air.
You are correct, there are different strength fans for different sub-slab-soil types. But the stronger you go, the more you need to test that the air is coming from under the slab, and not the conditioned air from the basement/house (you can test with a smoke pen/device all around to see how much air is being sucked and where). Leading into your question on how to test if the suction is adequate in all locations under the slab.
There's a tool that you can get to hook hoses up into and it will tell you the suction in various locations...I think it's a digital handhelt Manometer. You drill some small holes in multiple places around your basement, start sucking from you main location (with a shotback or radon system), then you will see if the suction is strong enough in all those locations. If the suction is not strong enough because of your soil type, you can drill 4 inch holes in the form of a line, separated by a foot or so, and dig up the dirt under the slab, creating a channel for the air to get to the suction point. Then seal the holes with concrete and caulk.
Because of the rubble stone walls...you really will be in the best situation if you talk to a professional radon mitigator. That can be complicated especially if you have water running through the stone. You can spray with something like gunite...but it should be professionally done.
If all floors are concrete, I would probably do the sub slab mitigation myself via that digging technique until suction is good enough under the both slabs, then make sure that everything from the footer up is 100% sealed. If radon persists, I'd talk to somebody about sealing the walls.
Also note that if you have low-none gravel content under the slabs, most of your air-draw will be from the perimeter of the house. (unless you do the drilling technique)
Can you guys provide a source for the drain cover with that ptrap? I can't find a source. I would appreciate it very much. Thanks
how much does this usually cost?....on an older home?
What is the Average price to install a radon migration system
The radon mitigation specialist that is looking at the home we are trying to buy said he needs to do a core sample to see if he can get pressure for a pump. The house was built in 1905. He also said he may not be able to install a pump because the old house might have a footer in the basement. Is there a solution for this?
Can people buy Products directly from you
i live in an older house with dirt below the concrete floor in the basement. i dont see any crushed gravel. with midigation systems still work in this scenario?
trying to figure that out as well. it is reccomdned for some old homes you just have the basement windows open with a fan in and fan out, but that would get cold in winter
@DavidB-j3p just so you know i went ahead and had a midigation system installed anyways on top of dirt. we dug out 5gallon bucket worth of dirt and installed a fan and the results were amazing. im in canada so my radon was over 600bq/ cubic meter and now my readings are less than 50bq!
@@pedrochip that sounds great, im gonna try 2 holes atleast 10-20 feet from eachother and connect them to the same fan via PVC
How many nonsmoking people who lived in that house over 110 years have died of lung cancer?
lol
why aren't these workers wearing hazmat suits and face mask filters?
yeah, that's not how radon works.