Additionally, a french drain may commence in the basement crawlspace. The system may terminate at any point where the water will not drain back toward the house. Installing a french drain is usually a simple, but labor intensive project. Obstacles, however, can make the project costly and time consuming. Some of the obstacles you may encounter are concrete walkways, driveways, tree roots, boulders, and underground utilities.
French drains are generally shallow drainage systems.
However, as with your plumbing waste drainage, french drain operate on the principle of gravity. The drain must slope downward. The minimum recommended slope is inch per foot. If the landscape grade runs upward along french drain path you'll will have dig deeper to maintain a downward slope. Barring any ostacles, a 4 inch diameter, 20' french drain can be created in a day.