The influence of radon penetration through joints on the overall radon barrier properties of waterproof membranes

• Published in: Journal of Building Engineering 2024-11, Vol.96, p.110604, Article 110604
• Main Authors: Jiránek, Martin, Kačmaříková, Veronika, Svoboda, Zbyněk
• Format: Article
• Language: English
• Subjects: Joints of membranes; Radon diffusion coefficient; Radon resistance; Radon-proof membranes; Waterproof membranes
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2024.110604

Waterproofing membranes with a proven ability to prevent radon penetration are commonly used to provide basic protection of buildings against radon from the subsoil. The goal of our research was to find out which types of joints of the pre-applied membranes are radon-tight and which, on the other hand, are radon permeable. Another goal was to find out how significant radon penetration through the joints can be, and how it can affect the ability of the whole radon-proof course to prevent radon penetration into the house. Six types of joints were investigated by determining the radon diffusion coefficient. Four of these types had a radon diffusion coefficient up to three orders of magnitude greater than the membranes themselves. A procedure was proposed for taking into consideration the high radon diffusion coefficient of joints in the calculation of the radon resistance of the whole radon-proof course. It has been proven that leaks in the joints can reduce the radon resistance of the whole radon-proof course by two to three orders of magnitude. For this reason, the course may not meet the minimum radon resistance requirements. Numerical simulation revealed that the leaks were due to the use of unsuitable sealing materials and technologies. A correct sealing technology for problematic joints was designed and subsequently verified. •The procedure for calculating the radon resistance of the whole waterproof course including joint leaks is presented.•Leaky joints can worsen the radon resistance of the whole waterproof course by up to three orders of magnitude.•Joints sealed with self-adhesive tapes can be significantly leaky.•Flame torching and hot air welding ensures radon-tight joints.