First thing I would do is make sure sump pump and sanitary pump are properly sealed. Often they aren't. Your biggest source of higher in home levels will come from those two. As part of the radon mitigation process, they do seal both. Newer construction probably required installion of a passive system when the property was built, which will also help dissipate higher levels, maybe. Or opening basement windows. Furnaces that draw outside air help too.
Also remember "safe" levels in US are 20% lower in US and twice as high elsewhere. So the science isn't exact.
|