North Carolina Building Contractor License Practice Exam

What is the maximum slope for permanent fill on a building lot?

1. 2:1

2. 1:1

3. 4:1

4. 3:1

The correct answer is: 2:1

The maximum slope for permanent fill on a building lot is typically 2:1, meaning that for every two units of horizontal distance, the fill can rise a maximum of one unit vertically. This steeper slope can be unstable and is generally avoided unless specific engineering analyses and design considerations have been implemented to ensure the stability of the fill. Using a 2:1 slope provides a balance between managing space effectively and maintaining safety standards against erosion and landslides. Slopes steeper than 2:1, such as 1:1 or even 4:1, may be inappropriate for permanent fills because they can increase the risk of failure. A 4:1 slope is safer and more stable, but it is not the maximum allowed; therefore, it does not meet the criteria for the specific maximum slope defined in regulations. A 3:1 slope similarly does not align with the maximum parameters as it falls somewhere between the 2:1 and 4:1 standards, reinforcing the idea that stability must be prioritized.