A NEW APPROACH TO THE ASSESSMENT OF RADON BARRIER PROPERTIES OF WATERPROOFING MATERIALS.

New definitions of the radon resistance and radon transmittance of waterproofing materials are introduced. They are based on the real steady-state radon distribution within the materials. Both quantities can therefore be considered as suitable parameters for the design of radon-proof insulations. A comparison between the existing definitions and the new definitions of radon resistance showed that the existing definition significantly underestimates the real radon resistance for a thickness to diffusion length ratio >0.8. It has also been proven that materials with different radon diffusion coefficients but with the same thickness to diffusion length ratio do not have the same radon resistance.