If you are dealing with stubborn water seepage, PU injection grouting is the gold standard for modern repair. This "non-hacking" method involves injecting liquid polyurethane into cracks at high pressure. Upon contact with moisture, the resin expands into a dense foam, effectively plugging the leak from the inside out. It is the preferred choice for HDB toilets and balconies in Singap... https://shakuraconstruction.sg/services/pu-injection-grouting/