Porcelain tile 12x24 rectified: pressed and fired at 2,200°F+. Water absorption <0.5% (ASTM C373). PEI wear rating: 4-5 (heavy to extra-heavy traffic). Breaking strength: >2,000 N (ASTM C648). DCOF (Dynamic Coefficient of Friction): ≥0.42 for wet areas per ANSI A326.3. Finishes: polished, matte, textured, wood-look, stone-look. Rectified = precision-cut edges, min grout joint 1/16 in (unrectified = 3/16 in). Installation: modified thinset mortar (ANSI A118.4), 1/4 x 3/8 x 1/4 trowel for 12x24. Substrate: cement board, mud bed, or concrete (deflection L/360 min). Uncoupling membrane (Ditra, StrataHeat) for crack isolation. Cost: $2-$12/sf material, $6-$15/sf installed. CSI 09 30 13. TCNA Handbook methods. Movement joints at 20-25 ft intervals and perimeter.