Florida Building Code Practice Exam

What condition necessitates waterproofing foundation walls and floors that retain earth and enclose spaces below finished ground level?

1. Hydraulic intrusion

2. Hydronic pressure

3. Exfoliation of groundwater table

4. Hydrostatic pressure

The correct answer is: Hydrostatic pressure

The necessity for waterproofing foundation walls and floors that retain earth and enclose spaces below the finished ground level arises from the presence of hydrostatic pressure. Hydrostatic pressure refers to the pressure exerted by a fluid at equilibrium due to the force of gravity. When water accumulates in the soil outside of foundation walls, it creates a significant load against these walls, especially in areas where the ground is saturated or in conditions like heavy rainfall or high groundwater levels. As this pressure builds up, it can lead to water infiltration if the structural elements are not properly waterproofed. This infiltration can cause various issues such as mold growth, material deterioration, and structural integrity problems. Therefore, the Florida Building Code emphasizes the importance of waterproofing in order to mitigate the potential for hydrostatic pressure to compromise the safety and longevity of structures with below-grade spaces. Other conditions, such as hydraulic intrusion or hydronic pressure, may also affect buildings, but they do not specifically encapsulate the broader issue of water pressure exerted from surrounding earth and groundwater, making hydrostatic pressure the correct reason for waterproofing requirements in these scenarios.