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Radon jumped from 3.6 to 6 AFTER installing stronger fan….

Asmithers | Posted in GBA Pro Help on


We had a radon mitigation system installed which brought our levels down from 8.8 to 3.6.  We have a basement and are using a sub-slab depressurization.  We wanted to get the levels down lower than 3.6 so we had them install the a stronger fan. At this point our Radon levels jumped up to averaging 6.0… we were shocked the Radon went up. I know weather can impact this, but we have been measuring it at around 6 for the past 30 days and it’s been consistent. We went ahead and had the mitigation contractor come back out and they installed a 2nd collection point hoping that would help.  So far the levels are averaging 5.5.  We are a little confused as to why the levels aren’t lower with the stronger fan.  We could hear “Whispers” from cracks that weren’t sealed up enough with the stronger fan and that was across the room so we know the suction is reaching.  The first collection point they drilled is a place that is prone to water collecting so I’m not sure how much that is impacting it.  The second collection point is in the middle of the basement and there is no water.  Any one have any ideas as to what could be causing this? I’m wandering if I should cap off the first collection point to send all the suction to the new one that is water free and in the middle of the basement.  

Any help would be greatly appreciated!


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