North Carolina Building Contractor License Practice Exam

What is the minimum slope required for site grading away from a building?

1. 1:20 (5% slope)

2. 1/4:12

3. 10 percent

4. 90 percent

The correct answer is: 10 percent

The minimum slope required for site grading away from a building is indeed essential for effective drainage and to prevent water from pooling around the foundation, which can lead to water damage or structural issues. A slope of 10 percent is equivalent to a 1:10 ratio, which means that for every 10 units of horizontal distance, there should be a 1 unit of vertical rise. This gradient is generally accepted as sufficient to ensure that water flows away from the building efficiently. A slope of 10 percent allows for adequate drainage without being too steep, which can cause erosion issues or make landscapes difficult to navigate. This slope is also generally manageable for landscaping and construction purposes, making it practical in a residential setting. Other options present different slopes, but they do not meet the commonly accepted requirements for effective drainage around buildings. A 1:20 slope (5% slope) is not steep enough to ensure effective drainage, while the ratios and slopes represented by other choices would either be too gradual or too extreme, thus detracting from their practicality for site grading applications.