Experimental estimation of the diffusion coefficient in radon barrier materials based on ISO/TS 11665-13:2017

Abstract

Due to the health risks posed by high radon concentrations, many regulations impose concentration restrictions and set out several techniques to prevent radon entry into enclosed spaces. One of the most effective technique to protect new buildings from radon entry is to install a radon barrier over the entire surface of the ground beneath the foundation. Whether a barrier is suitable for protection is determined by the diffusion coefficient, the methodology which is standardised in ISO/TS 11665-13:2017. These barriers are typically made of polymeric or bitumen materials, which have diffusion coefficients between 10−11 and 10−13 m2/s. By applying a modification to the ISO standard that allows shorter test times, the diffusion coefficients of a commercial membrane (6.21 ± 0.75 ·10−13), polyethene (1.14 ± 0.14 ·10−12), polypropylene (4.35 ± 0.53 ·10−14), polyvinyl chloride (3.55 ± 0.43 ·10−14), polystyrene (4.96 ± 0.60 ·10−13) and polymethyl methacrylate (4.07 ± 0.49 ·10−13) have been measured, the latter two material values not being published so far. The results validate the developed methodology since the diffusion coefficients provided are comparable with those of the literature. In all cases, a concentration reduction of 99% is obtained. A relationship is observed between the amount of radon adsorbed by the material and its thickness and chemical composition.