Alabama Contractors License Practice Exam

What is the minimum depth to which exterior footings must be placed?

1. 1 ft

2. 2 ft

3. 3 ft

4. 4 ft

The correct answer is: 2 ft

The minimum depth for exterior footings is crucial for ensuring stability and preventing issues related to frost heave and soil movement. In Alabama, footings must be placed at least 2 feet deep to provide adequate support for the structure and to ensure that the foundations are below the frost line. This depth helps to prevent the footings from being affected by the seasonal changes in temperature, which can cause the ground to expand and contract. Placing footings at this depth also helps in distributing the weight of the structure evenly across a larger area of soil, which can help prevent settling or shifting over time. In many regions, the frost depth varies, but 2 feet is commonly accepted as a safe depth to avoid potential frost damage and to ensure foundational integrity. Options that suggest a lesser depth would not offer the same level of protection from potential soil movement or instabilities that could occur, especially in regions that experience varying seasonal temperatures. Conversely, selecting a greater depth than necessary could lead to unnecessary excavation work and increased construction costs without providing significant added stability. Thus, the choice of a minimum depth of 2 feet is grounded in the need for safe and effective construction practices.