The three main types of exterior drainage systems are footing drains, French drains and perimeter drains. Constructors bury footing drains to go around the outside of the foundation walls of the house. The drains are located as low as at the level of the footing of the wall. Constructors place a layer of gravel to cover up the drain; the layer extends to the soil’s surface.
Footing drains carry water away from the house and dump it into a sewer basin, storm drain or the surface of the ground far away from the house.
French drains are installed on the surface of the yard; not buried deep into the soil. These drains collect water from the surface of the yard, and construction workers usually install them directly under downspouts. This way, they prevent the water from collecting and destroying the foundation of the house. French drains carry the water far away from the house after collecting it just like footing drains do.
Even though perimeter drains make up an exterior drainage system, they are typically located inside the house in the basement or crawl space floor. These drains get rid of the water inside the structure of the house. Perimeter drains usually intercept the water from the perimeter of the building.
All of these drain types must be installed at proper angles to adequately get rid of the excess water.