The Difference Between a French Drain & a Curtain Drain

French Drains

• A French drain, named for Henry French, an early advocate of the structure, is a landscape drain comprised of a sloped trench filled with gravel that directs water away from an undesirable location to a place where it will do no harm. Early French drains incorporated clay drainage tiles to speed the flow of water through the trench; contemporary French drains usually use perforated plastic pipe in the bottom of the trench for the same purpose. Gravel in the trench allows water to move from the soil into the drain while preventing sediment from migrating into the trench and clogging the drain.

Curtain Drains

• A curtain drain is a type of French drain that is positioned to intercept water before it reaches a location where it is not wanted and move it away to a more acceptable spot. For example, a curtain drain may be installed at the edge of a lot uphill from a home, where it will divert water entering the property safely to the edge of the lot, preventing it from traveling downhill and seeping into the home's basement. A curtain drain is generally shallow, often no more than 2 feet deep.

Footing Drain

• A French drain installed around the exterior perimeter of a building's foundation, usually at the level of the footer, is called a footing drain. This deeper type of drain may be necessary when a curtain drain, which is only able to divert surface water, is not sufficient to keep water out of a basement. A footing drain collects water before it can enter the basement, and moves it either away from the structure or to a holding tank from which it can be pumped to a storm water drainage system.

Interior French Drain

• When exterior drains are unable to keep water from entering a basement, a French drain may be installed in the interior of the basement itself. This type of drain is dug beneath the floor of the basement around the perimeter at the base of the walls, and it collects water as it enters the building. The water is then pumped either to a holding tank or directly to a storm drain system.