Masonry Wall Construction
masonry-wall-construction encompasses the structural requirements for solid masonry, hollow tile, concrete block, stone, and reinforced concrete walls as defined in the 1935 miami dade building code. These regulations ensure stability, fire resistance, and proper load distribution in buildings.
Foundations
Amendments to the building code specify strict curing and reinforcement requirements for masonry foundations across all building types (Types I through V) 1935-Miami-Dade-Building-Code_p325_344.
- Curing: All foundations for masonry construction must cure for at least 12 hours before any masonry elements are laid (p. 334).
- Low Walls: Foundations for masonry walls used for fences, planting boxes, or walls up to four feet in height must be at least 10 inches wide and 8 inches deep, reinforced with 2 1/2” rods (p. 334).
Solid Masonry Walls
Solid masonry walls, whether bearing or non-bearing, must adhere to strict thickness requirements based on building height and occupancy group 1935-Miami-Dade-Building-Code_p225_244.
- Thickness: Exterior bearing walls may be of lesser thickness if constructed per specific provisions (p. 225). Non-bearing walls must meet minimums in Table 3 (p. 225).
- Reinforcement: Walls in Groups H and I buildings under three stories require structural columns at intervals not greater than 16 feet and tie-beams at each floor level (p. 225).
- Bonds: Every sixth course must be a header course, or one full header per 72 square inches of wall surface (p. 225).
- Piers: Unsupported height of isolated piers shall not exceed 10 times their least dimension (p. 225).
Hollow Walls
Hollow walls constructed of clay tile, concrete block, or hollow brick have distinct lateral support and thickness mandates 1935-Miami-Dade-Building-Code_p225_244.
- Lateral Support: Must be supported at right angles to the face at intervals not exceeding 16 feet (p. 226).
- Air Spaces: Combined air spaces and cellular space cannot exceed 45% of the gross cross-sectional area (p. 227).
- Thickness: Minimum thickness is 12 inches for the uppermost 25 feet, increasing by 4 inches for each successive 25 feet downward (p. 227).
- Piers: Hollow tile piers must be filled with cement grout or concrete and reinforced with steel bars (p. 228).
Reinforced Concrete Walls and Columns
Reinforced concrete walls are governed by general provisions and specific stress limits 1935-Miami-Dade-Building-Code_p225_244.
- Thickness: Bearing walls must be at least 1/25 of the unsupported height (p. 228).
- Stresses: Maximum allowable compressive stress is when unsupported height is 25 times thickness (p. 229).
- Reinforcement: Minimum reinforcement is 0.1% in each direction, distributed equally to each face (p. 229).
- Columns: Concrete columns are required at all corners and at specified intervals. They may be the same thickness as the walls or a minimum of 8 inches thick and 12 inches wide, reinforced with four 5/8” continuous vertical rods and 1/4” ties spaced on 12” centers. U-Type Blocks are not permitted for reinforced concrete column use (p. 336).
- U-Type Beams: The unsupported maximum span for U-Type Beam Blocks is 7 feet, reinforced with two 7/8” rods minimum, placed one on top and one in the bottom of the beam (p. 336).
- Tie Beams: An 8x8 inch reinforced concrete tie beam is required at the rakes at the end of gables, unless the rake and height are less than 24 inches (p. 338).
Stone and Veneered Walls
- Stone Walls: Rubble stone walls must be 4 inches thicker than solid brick walls of similar height, with a minimum of 16 inches (p. 230).
- Veneered Walls: Veneering materials like glass veneer, stone, and terra cotta have specific minimum thicknesses and anchorage requirements (p. 231). Glass veneer must be at least 11/32” thick (p. 232).
Fire Walls and Partitions
Masonry construction plays a critical role in fire-wall-construction and vertical-opening-enclosure.
- Fire Walls: Solid masonry fire walls must be at least 12 inches thick (p. 234). Hollow masonry fire walls are prohibited in fire-zones No. 1 (p. 235).
- Partitions: Bearing partitions must be at least 8 inches thick (p. 236).
These standards relate to broader concepts of fire-resistive-construction-requirements and structural-load-calculations.