Paddy
Veteran Member
We did a test in our basement a while back and had high readings. I can't recall what our reading was at the time. But my wife is pushing to do something about it.
We ordered a tester;
InspectUSA.com Electronic Radon Gas Detector and Alarm (HS71512) EPA Approved
I figured I want to retest in several places in the house and basement before and after, those mail off types could add up to be more than just buying a measurement tool.
I need to do a bit of sealing first. When when designed and built our home, we left a 7 ft by 7 ft elevator shaft going from basement to the second floor. I left the 7 x 7 area in the basement floor open, no slab. So good news, a place set the sump/pipe for the fan to put a negative pressure under the slab.
We have a poured concrete basement walls and floor, 3800 sq-ft. About 8 inches of crushed stone under the slab, gravel even to the top of the footer.
I get the basic concept of the Sub slat suction method, make a slight vacuum and any gas that would normally rise via cracks and gaps between slab and wall will be drawn out the 4" pipe. If the suction pipe is really sealed to the slab, the only out put will from under the slab. I assume the output of the fan should be quite small. How much air can leak through a hairline crack? The slab at the edges is poured on top of the footers.
Our basement is huge and has poured internal walls so we are likely facing several suction points. One method to determine if you are creating enough suction is a vacuum test. Imagine drilling a 2 in hole and sealing a 2 in shop vac hose to it. Then at some given distance drill a 1/2 in hole and see if there is suction. One way to see if there is suction at the 1/2 in hole is to insert a 1/2 in tube and see if it will draw water up any bit.
One thing I read is making a sump, or pit under the slab where you have the 4 in pipe for suction. I don't see how having large void or a small void would have any difference. Suction is suction. Volume is controlled by how many cracks/gaps and the out put pipe dia.
Anyone install a Radon removing system?
We ordered a tester;
InspectUSA.com Electronic Radon Gas Detector and Alarm (HS71512) EPA Approved
I figured I want to retest in several places in the house and basement before and after, those mail off types could add up to be more than just buying a measurement tool.
I need to do a bit of sealing first. When when designed and built our home, we left a 7 ft by 7 ft elevator shaft going from basement to the second floor. I left the 7 x 7 area in the basement floor open, no slab. So good news, a place set the sump/pipe for the fan to put a negative pressure under the slab.
We have a poured concrete basement walls and floor, 3800 sq-ft. About 8 inches of crushed stone under the slab, gravel even to the top of the footer.
I get the basic concept of the Sub slat suction method, make a slight vacuum and any gas that would normally rise via cracks and gaps between slab and wall will be drawn out the 4" pipe. If the suction pipe is really sealed to the slab, the only out put will from under the slab. I assume the output of the fan should be quite small. How much air can leak through a hairline crack? The slab at the edges is poured on top of the footers.
Our basement is huge and has poured internal walls so we are likely facing several suction points. One method to determine if you are creating enough suction is a vacuum test. Imagine drilling a 2 in hole and sealing a 2 in shop vac hose to it. Then at some given distance drill a 1/2 in hole and see if there is suction. One way to see if there is suction at the 1/2 in hole is to insert a 1/2 in tube and see if it will draw water up any bit.
One thing I read is making a sump, or pit under the slab where you have the 4 in pipe for suction. I don't see how having large void or a small void would have any difference. Suction is suction. Volume is controlled by how many cracks/gaps and the out put pipe dia.
Anyone install a Radon removing system?
