auradeus Posted October 21, 2015 Report Share Posted October 21, 2015 Looking for some advice on a minor radon issue I'm facing. I've tested radon several times over the past two years, including two three-month tests. Radon levels are generally below 4 pCi/l, but one test did spike to 5.5 pCi/l. Radon is only at higher levels in the basement, which is very airtight (new construction, built in 1997). Related to the 5.5 pCi/l test (a 3-month test), where I live near Boston received record winter snow during the test. It is likely the pressure of the snow increased flow of radon into the basement. Looking to try conservative radon mitigation techniques before considering installing a sub-slab suction radon mitigation system, given my levels are borderline. There is a relatively large penetration in the basement slab for the drain to the city sewer. I inserted a picture below. The penetration is about 2' X 2', a little smaller. This is a prime area for radon to enter the basement in high volumes. I'm considering sealing up this area with hydraulic cement, perhaps putting a foam or rubber sleeve around the sewer pipe to alleviate pressure upon expansion of the cement. I have not been able to find guidance whether this is acceptable under building code, but this was one option a local radon mitigation contractor suggested. He also suggested sealing with 6mm plastic using strapping and wire (couldn't really follow what he was recommending, we only spoke on the phone). I realize that this is not a true fix for radon, and that radon will seep through any microscopic crack in the slab. I'm simply trying to slow the flow of radon into the home such that natural ventilation (i.e. opening basement windows, there are many) on occasion will keep levels below 4 pCi/l. Any suggestions or advice is very welcome. Thank you in advance. Click to Enlarge 50.13 KB Quote Link to comment Share on other sites More sharing options...
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