THE INS AND OUTS OF DRAINS“French Drains”: Everyone has them, right? Well, usually not. Most of the time whenpeople (and even contractors) say “French Drains”, that’s not really what they mean. True
professionals know what they’re talking about!
There are 3 basic types of drainage systems: French Drains, Area Drains, and Trench Drains.
Let’s start with the ever-popular French Drain.
French Drains are designed specifically and ONLY to collect underground water, andcannot be seen from the surface. This type of drain consists of a trench that is lined with geotech cloth (or landscape fabric) to prevent roots from eventually growing into the drain andclogging it. A perforated (or slotted) pipe is placed in the ditch, and then the ditch is filledwith rock nearly to ground level. The surface of the ditch is then covered with more geo-tech
cloth and then 3-6” of soil to allow vegetation growth over the top of the drain. French
Drains are rarely less than 3 feet deep, and can go as deep as 6 or 7 feet in some cases, andtypically run the length of an entire side or multiple sides of a building to prevent
underground water flow from going under the foundation and effecting stability. Due to thedepth of these drains, they are most often drained into a sump box, and the water pumped out
to the nearby street or alley. Again, these drains are not designed to collect surface water(such as rain or sprinkler runoff) and, therefore, gutter downspouts and collection basinsshould never be connected to a French Drain.
Area Drains (also called Surface Drains) are designed to collect rain and sprinkler
runoff and channel it away from low areas. They consist of collection boxes with a grate on
top, which are buried into the ground so that the grate on top is flush or just below groundlevel. These boxes are connected by a pipe (run typically 4-8” deep) and drains to a nearby
street or alley either by gravity, or sometimes by pump. Gutter downspouts can and should beconnected directly to an Area Drain system.
A rarely used hybrid of the two is called a Modified French Drain or a “Trench”
Drain. While a Trench Drain is designed primarily to collect surface water, this drain isconstructed the same as a French Drain with only a couple of differences. First, it is rarely as
deep as a true French Drain, typically only being between 1 and 3 feet in depth. Secondly,
instead of covering the drain with soil to allow vegetation to grow over the drain, the Trench
Drain contains rock or gravel that extends all the way to the surface. The Trench Drain isinherently just a very long and continuous collection drain basin. It is ideal for areas withsignificant slopes where water does not simply pool in a few low spots, but instead flowsthrough a large area. As the water flows down a hill and toward a home, say, it falls throughthe rocks into the Trench Drain, and is directed away in the pipe, usually around the home andto lower areas where it is again released, or into a sump box and pumped away from theproperty.
Hopefully this clears up any confusion or misconceptions about drains. For any questions,concerns or comments, please contact us at any time!

Office: 469-698-8332

2850 Shoreline Tr., Suite #20, Rockwall, TX 75032

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