For serious structural cracks, a toilet water seepage problem requires high-pressure PU (Polyurethane) injection. This industrial-grade solution involves injecting an expanding resin into the underside of the leaking slab. Upon contact with moisture, the resin expands to fill every void, creating a permanent, flexible seal that withstands high water pressure. This "negative side" repa... https://shakuraconstruction.sg/toilet-water-seepage-problem/