Foundation Ventilation Requirements specify the necessary airflow provisions for enclosed spaces beneath building floors, particularly in construction-type-classifications classified as Type II. These requirements are designed to prevent moisture accumulation and decay in wooden structural elements.
According to the 1935-Miami-Dade-Building-Code_p165_184, solid foundation walls under the first floor joists of Type II buildings (excluding basements or cellars) must include ventilated openings (p. 165). These openings must be covered with non-corrosive wire mesh of not less than 16 mesh per lineal inch to prevent pest entry while allowing air flow (p. 165-166).
The size and distribution of these vents are strictly regulated:
- Area: Not less than 2 square feet of opening for every 15 lineal feet (or major fraction thereof) of exterior foundation wall (p. 166).
- Distribution: Openings must be distributed on not less than three sides of the structure to produce adequate cross-ventilation in at least one direction (p. 166).
These ventilation standards work in conjunction with other foundation requirements, such as the 18-inch clearance between floor joists and the ground (p. 165) and the prohibition of loose wood storage under buildings (p. 166), to maintain the integrity of the reinforced-concrete-design and wooden structural components.