Proper surface preparation is key to successful waterproofing. For this apartment building in Don Galo, Parañaque City, the roof deck had developed structural cracks due to persistent water penetration and the failure of a previous waterproofing system. Before a new system could be applied, IAJR Construction removed the old membrane and utilized CONFIX IJ to repair the damage. The low-viscosity epoxy effectively penetrated the cracks, filling all gaps and achieving a compressive strength of 12,000 psi, ensuring the slab was restored to a monolithic state.