A foundation drain must extend past the outside edge of the footing by at least how far?

A foundation drain is designed to collect and redirect groundwater that may accumulate around the foundation of a building. Extending the drain past the outside edge of the footing by at least 12 inches is critical for ensuring that the drainage system effectively manages water and prevents it from penetrating the foundation wall. This extension helps to reduce the hydrostatic pressure against the walls, minimizing the risk of water damage, mold growth, and structural issues that can arise from prolonged exposure to moisture.

By adhering to the 12-inch extension requirement, the drain captures water sufficiently before it can pool around the foundation. This practice is part of proper foundation drainage design, ensuring that the ground water is directed away from the foundation area effectively. If the drain does not extend sufficiently, it may not capture enough water, leading to potential water-related problems. Thus, the necessity for this specific measurement is rooted in both engineering principles and best practices in construction.