The correct answer is that the grade around a property's foundation walls should be dropped a minimum of 6 inches within the first 10 feet. This principle is crucial for effective drainage and to prevent water accumulation around the foundation. A downward slope allows rainwater and runoff to move away from the structure rather than pooling next to the foundation.
Proper grading is essential for minimizing moisture-related issues, such as mold growth and foundation damage caused by hydrostatic pressure. By ensuring that the ground slopes adequately, it contributes to the structural integrity of the home and helps to protect against water intrusion in basements or crawl spaces. This practice is part of a standard approach in landscaping and construction to ensure that buildings remain dry and protected from the elements over time.
While other depths of slope may exist, the standard recommendation for effective drainage management is 6 inches within the first 10 feet, as it provides a balance between sufficient runoff and practicality in landscaping.