PU Injection Grouting: Fast & Non-Invasive Leak Sealing Solution PU injection grouting is a leading remedial waterproofing method that stops active water leaks instantly in Singapore's humid, rainy climate. Hydrophobic polyurethane resin is injected under pressure into cracks, joints, or voids in concrete. Upon contact with water, it expands rapidly (up to 20–30 times), forming a fle... https://shakuraconstruction.sg/services/pu-injection-grouting/