The ground adjacent to the foundation shall be sloped away at not less than 5 percent for a minimum of ______ feet.

The ground adjacent to the foundation shall be sloped away at not less than 5 percent for a minimum of ______ feet.

• A. 5
• B. 10
• C. 15
• D. 20

Answer: (B)

Ground around a foundation should drain away to prevent water from seeping into the structure. A 5 percent slope means a vertical drop of 0.05 feet for every 1 foot of horizontal distance. To satisfy this slope, you need enough distance to realize that drop. Over ten feet, the grade would drop about 0.5 feet (6 inches), which provides a clear away-from-wall drainage. Five feet would only give about 0.25 feet (3 inches) of drop, which doesn’t meet the 5% requirement over that distance. Longer runs would also satisfy the slope, but ten feet is the minimum needed to maintain the 5% grade.

Ground around a foundation should drain away to prevent water from seeping into the structure. A 5 percent slope means a vertical drop of 0.05 feet for every 1 foot of horizontal distance. To satisfy this slope, you need enough distance to realize that drop. Over ten feet, the grade would drop about 0.5 feet (6 inches), which provides a clear away-from-wall drainage. Five feet would only give about 0.25 feet (3 inches) of drop, which doesn’t meet the 5% requirement over that distance. Longer runs would also satisfy the slope, but ten feet is the minimum needed to maintain the 5% grade.