This section of the 1935-miami-dade-building-code establishes minimum protection standards for structural components, fire-resistive assemblies, and public space usage during construction.
Structural Fire Protection
The code specifies minimum thicknesses for incombustible insulating materials based on required fire-resistive periods (1 to 4 hours) structural-fire-protection-tables (p. 285). Key distinctions are made between:
- Steel and Cast Iron: Columns, beams, and trusses require varying protection depending on material, such as Grade A or B concrete, gunite, brick, or gypsum blocks (p. 285).
- Concrete Aggregates: Grade A concrete uses aggregates with less than 65% siliceous material, while Grade B uses others; unknown aggregates default to Grade B (p. 286).
- Reinforcement: Specific cover depths are mandated for reinforcing steel in columns, beams, joists, and slabs (p. 285).
Fire-Resistive Walls and Partitions
Section 4302 details requirements for bearing and non-bearing walls fire-resistive-construction-requirements (p. 287). Minimum thicknesses are provided for various constructions, including:
- Solid or hollow brick, concrete, and clay tile walls (p. 288–289).
- Hollow gypsum blocks and reinforced gunite shells (p. 289).
- Plastering requirements: Gypsum or Portland cement plaster must be at least ½ inch thick on each side to contribute to fire resistance (p. 287).
Floor and Ceiling Protection
Fire-resistive floor construction is categorized by rating floor-construction-standards:
- Three-hour: Requires reinforced concrete, gypsum, or solid masonry slabs not less than 4 inches thick, or hollow masonry with a 2-inch solid top covering (p. 291).
- Two-hour: Requires slabs not less than 2½ inches thick or hollow masonry not less than 3 inches thick with a 1-inch solid top covering (p. 291).
- One-hour: Allows for wood joisted construction with a double wood floor and fire-resistive ceiling, provided specific thicknesses are met (p. 291). Ceiling protection thicknesses may be reduced by ½ inch if a free air space of at least 1 inch exists between the member and protection (p. 291).
Fire Doors, Shutters, and Windows
Section 4304 outlines specifications for one-hour fire-resistive doors fire-resistive-door-specifications (p. 292). Acceptable types include:
- Tin-clad wood-core doors (p. 292, 293).
- Sheet metal doors with asbestos insulation (p. 292, 293).
- Metal-clad wood panel doors (p. 293). Hardware must be of heavy-duty malleable iron or steel, and sliding tracks must be securely supported (p. 293). Fire-resistive windows must use wire glass at least ¼ inch thick, with maximum light areas of 720 square inches (p. 294–295).
Roof Coverings
Section 4305 classifies roofs as “Fire Retardant” or “Ordinary” roof-construction-standards (p. 295).
- Fire Retardant Roofs: Must meet underwriters-laboratories Class A or B specifications or specific layer requirements for roll roofing, felt, shingles, or tile (p. 295–297). Concrete slab roofs need no additional covering (p. 297).
- Ordinary Roofs: Meet Class C specifications or specific lighter layer requirements (p. 298).
- Wood Shingles: Must be heartwood (e.g., red cedar) and meet specific thickness and exposure standards based on roof pitch (p. 298–299).
Construction and Public Property
Chapter 44 regulates temporary street use during construction (p. 301). In fire-zones No. 1 or for buildings over two stories, a temporary covered walkway at least 5 feet wide and 8 feet high must be constructed to protect pedestrians (p. 302). Chapter 45 restricts permanent projections over public property, allowing limited extensions for cornices, marquees, and balconies under strict conditions (p. 303–304).
Related Concepts
- structural-fire-protection-tables
- fire-resistive-door-specifications
- fire-resistive-construction-requirements
- fire-separation-standards
- roof-construction-standards
- building-material-specifications
- floor-construction-standards
- construction-type-classifications