Alabama Contractors License Practice Exam

A sump is not required for walls supporting less than how many feet of backfill?

1. 3 feet

2. 5 feet

3. 2 feet

4. 4 feet

The correct answer is: 3 feet

In construction, a sump is typically used to collect and discharge water that accumulates in an area, particularly where there may be a risk of water infiltration around basement walls or foundations. The requirement for a sump is often related to the amount of backfill soil pressure that walls must support. When walls are supporting less than 3 feet of backfill, the pressure exerted by the soil is generally considered manageable without the need for additional drainage systems like a sump. This is largely because the risk of water accumulating and exerting damaging lateral pressure on the walls increases with greater backfill depths. Therefore, for less than 3 feet of backfill, standard drainage practices may adequately handle any potential water infiltration without necessitating a sump to prevent structural issues. Understanding this requirement helps contractors to gauge when to implement more sophisticated drainage solutions for excavation sites based on the amount of backfill being supported, contributing to better planning, construction practices, and site management.