IBC Ch21: structural masonry per TMS 402/602. Section 2101 — masonry units: concrete (ASTM C90), clay (ASTM C62/C216), AAC (ASTM C1693). Mortar: ASTM C270 (Types M, S, N, O). Grout: ASTM C476 (minimum 2,000 psi). Section 2106 — special inspections: Level 1 (periodic) or Level 2 (continuous) per IBC 1705.4. Required for all engineered masonry and empirical masonry in SDC D+. Section 2107 — ASD per TMS 402 Chapter 8. Section 2108 — strength design per TMS 402 Chapter 9. Section 2109 — empirical design (limited to 35 ft, non-seismic). Section 2110 — glass unit masonry (glass block). Section 2104 — construction: cold weather protection (maintain 40F for 24 hrs), hot weather (wet units, shade mortar).