No, it’s not a place where you go to get wasted on the finest Evian around. It’s used to waterproof construction joints of retained concrete structures so that they become integrally waterproof – defined within BS8102:2009 as Type B waterproofing. A construction joint is where one form of construction stops and another starts, thus forming a weak path for water to enter through. Hydrophilic water bars are regularly used when activated by moisture. It’s characterised by high elasticity and high tensile strength. It is usually made of natural sodium bentonite clay and synthetic rubber. When it comes into contact with water it can expand up to 400%, from what I’ve seen it at least doubles its dry volume forming a positive seal.
Waterbar can be included in; both vertical and horizontal non-moving concrete construction joints, new to existing concrete construction, irregular surfaces and around through wall penetrations such as plumbing and utility pipes. Water bar can be; mounted using adhesive onto a cleaned substrate. Where there is around 80mm of concrete cover from the water bearing side it can be mechanically fixed. The waterbars should come with a test certificate for authenticity. They usually come in 25m lengths and ranging from 190mm to 320mm wide. When visiting site, I have seen waterbar used when a basement wall is being erected and the perimeter wall is being built up.