Grout prevents contaminationProblemA broken sewer line in Baltimore, Md., allowed wastewater to infiltrate voids in the mortar joints of a brick stormwater vault. Officials looked for ways to seal the leaks.SolutionContractors applied a hydrophilic polyurethane grout from Fox Industries/Simpson Strong-Tie. They used an airless spray pump attached to injection ports to reach the void behind the vault. As the material contacted water, it foamed, expanding up to seven times its original mass and creating a flexible, waterproof membrane. Workers patched the port holes with hydraulic cement.ResultOnce the material cured, workers could apply various skim coats to unify the vault's appearance
