Applicability of various insulating materials for radon barriers

The effectiveness of various insulating materials for limiting radon entry into houses has been investigated under laboratory conditions. Results for the radon diffusion coefficient measurements in more than 80 insulating materials are summarized. We have discovered that great differences exist in diffusion properties, because the diffusion coefficient varies within four orders from 10 13 m2 s to 10 10 m2 s. A methodological approach is proposed in order to identify the minimal thickness of radon-proof membranes, depending on building and soil characteristics. General guidelines for the selection of radon-proof insulation are presented.