What is the minimum slope required for grade adjacent to a structure?

The minimum slope required for grade adjacent to a structure is essential for proper drainage and to prevent water accumulation near the building. A slope of 5% is commonly recommended as it effectively directs water away from the foundation, reducing the risk of water infiltration and potential damage to the structure. This minimum slope means there is a drop of 5 feet for every 100 feet of horizontal distance, which adequately facilitates drainage while ensuring that the area remains functional and accessible for landscaping or other uses.

Selecting this slope helps to maintain the structural integrity and longevity of buildings by alleviating potential issues such as erosion and moisture buildup, which can lead to serious foundation problems over time. While other options may indicate steeper slopes, a 5% slope very effectively meets the necessary drainage requirements without being excessively steep for practical landscaping or usage considerations.