PU (Polyurethane) Injection Grouting is one of the most advanced and reliable techniques for sealing water leakage and strengthening concrete structures. Ideal for basements, retaining walls, terraces, bathrooms, and other water-prone areas, this method involves injecting high-grade polyurethane resin into cracks and voids. Upon contact with water, the material expands and hardens, creating a watertight, flexible seal that blocks further leakage and restores structural integrity.