International Compliance Association (ICA) Home Inspector Practice Exam

What is the BEST grade allowance to prevent foundation compromise due to soil?

1. At least 1" per foot for four feet

2. At least 1" per foot for six feet

3. At least 1" per foot for eight feet

4. At least 2" per foot for six feet

The correct answer is: At least 1" per foot for six feet

The best grade allowance to prevent foundation compromise due to soil is established by ensuring that water does not accumulate around the foundation, leading to pressure on the walls and potential structural issues. A grading allowance of at least 1 inch per foot for six feet effectively promotes proper drainage. This measurements allows for a significant slope to encourage water runoff away from the structure. The rationale for selecting this specific allowance is that a slope of 1 inch per foot over six feet results in a total elevation change of 6 inches, which is an adequate distance to guide water away from the foundation effectively. It helps to mitigate erosion and maintain soil stability, promoting a healthy environment around the foundation. In contrast, a grade of 1 inch per foot for four feet would not provide enough of a slope to effectively manage water drainage over a larger distance, potentially allowing water to pool near the foundation. On the other hand, while an allowance of 2 inches per foot does provide a more rapid slope, this steepness could lead to erosion or possible instability in the surrounding soil, making it less practical for maintaining a stable environment. Lastly, a grade of 1 inch per foot over eight feet, while theoretically sufficient, may be less effective than the six-foot allowance in ensuring swift drainage