Visqueen Ultimate RadonBlok 400 is a unique high performance co-polymer thermoplastic radon barrier that is manufactured using Visqueen’s advanced membrane technology. Ultimate RadonBlok 400 is a flexible barrier membrane that works in extreme conditions providing complete protection from sealing floors to walls and also complex detailing (such as service pipe penetrations and corners). Designed specifically for the environmental challenges of the Irish market, it has 1.5x the impact strength of traditional reinforced radon membranes and increased flexibility, even in sub-zero temperatures, prevents problems with cracking and makes installation easier. RadonBlok 400 is 2m x 25m x 0.4mm and is a taped system. IAB certified radon barrier system.