French Drain Fundamentals

As a professional drainage contractor, we get a lot of requests for French drain systems.  French drains remove excess water from the soil.  Whether you want to tackle this project as a DIYer or hire a professional company to complete the installation, you need to pay attention to 4 key installation elements that will increase the effectiveness and longevity of your French Drain System.  

Excavation:

For your French Drain to work properly, construct a wide and deep trench, approx. 12” wide and 8-14” deep, in the area where the soil lacks drainage.  You can create a trench by hand with a shovel or utilize an excavator.  It’s important that you not return the excavated soil to the trench when the digging is finished.  Remove excavated soil off location or utilize the soil in other places around the property where it can improve the grade, such as near foundations or low spots.

Soil Separator:  

Create a barrier between the soil and the French drain system. Line the trench with a non-woven Geo fabric to help prevent material from the surrounding soil from entering the system. The Geo fabric will wrap the piping and rock like a burrito, helping create a clog-free system.  

Perforated Pipe:

Small holes along the corrugated pipe allow water to migrate inside the piping and drain. Place the perforated pipe on the bottom of the trench laying directly on the soil separator. Make sure piping has at least a 1% slope to allow proper water flow.

Rock:

Rock within the French drain creates large voids, allowing water to move quickly through the system.  Use a large stone such as 1” clean gravel or 1 -2” smooth stone in your French Drain system.  The larger the rock the better.  Avoid using pea gravel or ¾” clean stone.  

 

For over twenty years, Teachers Irrigation has been installing French drains in the Kansas City area. If you are plagued by drainage issues and are worried about damage to your home or landscaping, the experts at Teachers Irrigation are here to help. Whether it’s burying downspouts or sump pump discharge lines, installing sump pumps or French drains, we are your go-to for all drainage solutions.