Florida Building Code Practice Exam

When hydrostatic pressure conditions exist, how high must waterproofing extend from the bottom of the wall?

1. The top of the footing to not less than 8 inches above finish grade

2. The top of the footing to not less than 12 inches above finish grade

3. The bottom of the wall to not less than 8 inches above the groundwater table

4. The bottom of the wall to not less than 12 inches above the groundwater table

The correct answer is: The bottom of the wall to not less than 12 inches above the groundwater table

The correct answer states that waterproofing must extend from the bottom of the wall to no less than 12 inches above the groundwater table when hydrostatic pressure conditions are present. This requirement is based on the understanding that groundwater pressures can significantly affect the integrity and performance of a foundation wall. By ensuring that waterproofing extends above the groundwater table, it helps to mitigate the risks of water infiltration, which can lead to structural problems, mold growth, and other hazardous conditions within the building. A critical aspect of waterproofing is to create a barrier that prevents water from entering the structure. In situations where hydrostatic pressure is a concern, having this waterproofing extending well above the groundwater level is essential to withstand potential water pressure that could push against the walls. The other answers indicate varying distances related to the finish grade or groundwater table but do not account for the specific requirements needed to protect against hydrostatic pressures adequately. Ensuring waterproofing exceeds the groundwater level by a sufficient margin is vital for long-term building stability and safety.