According to (NASSCO) National Association of Sewer Service companies chemical grout started in 1955. Polyurethane grout has been used in tunnels, elevator pits, manholes, tanks, and even to lift slabs. Studies show that 40% of groundwater leaks in the sewer systems enter through manholes. When this happens over time the manhole will start to break down and needs to be rehabbed. Both Hydrophobic and Hydrophilic grouts can be used to seal leaks in all types of concrete structures. Here are a just few of our water activated products that are used on a daily basis.