Masonry unit type. CMU_hollow is the most common for structural walls. CMU_solid and clay_brick have higher net area and weight. If omitted, defaults to 'CMU_hollow'.

Nominal wall width in inches. Standard CMU sizes: 4, 6, 8, 10, 12 in. Most structural bearing walls use 8 or 12 in. Standard CMU widths: 4, 6, 8, 10, 12 in. 8 in is most common for bearing walls. If omitted, defaults to 8 in.

Unsupported wall height in feet between lateral supports (floor to floor or floor to roof). Drives slenderness ratio; TMS 402 limits h/t to 30 for bearing walls. Typical: 8-30 ft for single-story, limited by h/t slenderness. If omitted, defaults to 12.0 ft.

Mortar type per ASTM C270. Type S is standard for structural walls; Type M for below-grade or high lateral loads; Type N for non-structural veneers. If omitted, defaults to 'S'.

Axial dead + live load in pounds per linear foot of wall. Includes tributary floor/roof loads. Typical range: 500-5000 plf for bearing walls. If omitted, defaults to 1000 plf.

Lateral pressure on the wall face in pounds per square foot. Wind load per ASCE 7 or seismic out-of-plane pressure. Typical wind: 15-40 psf. If omitted, defaults to 20 psf.

Specified masonry compressive strength f'm in psi. If omitted, looked up from reference table by unit_type, width, and mortar type. Common values: 1500-3000 psi for CMU.

Whether the wall cells are fully grouted. Grouted walls use gross area for stress calculations; ungrouted walls use net area. Grouting increases weight and capacity. If omitted, defaults to False (ungrouted).