Lubon Infra Chem executed comprehensive internal waterproofing works for two fire tanks, delivering a multi-layered system focused on leakage control, crack repair, joint sealing, and long-term protection of RCC surfaces. The work began with chipping and disposal of existing plaster, followed by detailed surface preparation to remove laitance, oil, dirt, loose particles, protrusions, and other contaminants, ensuring a clean and sound base for waterproofing treatment. All cracks, construction joints, honeycombed areas, pipe penetrations, and bore packings were treated through groove cutting, polymer-modified repair mortar, chemical injection grouting, PU grouting where required, and flexible TPE sealing tapes to create watertight continuity at vulnerable points. Special attention was given to wall-floor junctions through SBR-modified coving, while pipe areas were sealed with repair mortars and grouting systems to prevent seepage around penetrations. The tank surfaces were then coated with a food-grade elastomeric waterproofing membrane in multiple coats to provide flexibility, adhesion, crack-bridging ability, and durable water resistance. To protect the waterproofing system, horizontal and vertical protection layers were applied using waterproofing admixture-based screed and plaster. This complete internal tank waterproofing solution was designed to provide reliable resistance against leakage, water pressure, structural cracks, and long-term deterioration, ensuring durable performance for critical fire water storage structures.