This technical guide establishes rigorous Wet Area Specifications for natural stone installations, prioritizing the prevention of bond failure in high-salinity and submerged environments. We evaluate the chemical superiority of non-water-soluble epoxy resins and high-density quartzite and slate panels over standard cementitious systems. The report details critical moisture barrier selections, ASTM C920 sealant protocols, and CNC diamond-blade interlocking strategies to mitigate efflorescence and salt crystallization. For B2B stakeholders, these engineering standards are the primary defense against delamination claims, ensuring structural integrity for pool, spa, and coastal developments through 2026.