What is a French Drain?

What is a French Drain?

Drainage problems in your yard can cause a lot of damage and can lead to pooling, potentially causing plants and grass to rot, mold to grow and water damage to your home. A French drain is one solution that can divert water away from your home, gardens and other valuable landscape areas.

Basically, a French drain is a mechanism to remove water and direct it to a more appropriate outlet such as a pond or existing drainage. Its primary purpose is to prevent ground and surface water from damaging a building’s foundation. The French drain is an alternative to the more well-known sump pump. A sump pump is a pump used to remove water that has accumulated in a basin, commonly found in the basements of homes.

With a French drain, the water runs into a trench filled with rocks. A perforated pipe sits at the bottom of the trench and redirects the water away from your house. If you’re thinking about installing a French drain, the first thing to do is call an expert. Why? Because before you install the drain, there are specific steps you must take to install it properly. You can review the steps below.

Choose the location.

The location of your water problem stipulates where the French drain should be located. You also need to consider elevation and the condition of the soil (sandy soil is preferred). Then you should prepare to dig.

Get ready to dig.

It’s important to dig safely. Contact your local utility company to have them mark any underground lines. You also need to be cognizant of city codes and how the French drain will affect your neighbors. Now it’s time to mark the trench’s lines and start measuring the grading.

Measure grading.

To measure the grading, install two stakes into the ground marking the sides of your trench. Then tie a string between them, which will help you measure the grading of the trench. The trench bottom should slope one inch for approximately every eight or nine feet toward where you want the water to go.

Dig the trench.

Now you’re finally ready to dig. This step will take the most time, as you’ll need to measure the grading as you dig. The trench’s width with vary, as it depends on how much water you need to drain. A five-inch wide and eight-inch deep trench can handle most issues. However, significant drainage problems may require larger trenches.

Install landscape fabric.

After digging your trench, it’s now time to line it will landscape fabric. The fabric’s purpose is to push the water out and prevent gravel from mixing with dirt. Once installed, shovel gravel over the fabric to hold it in place.

Add the pipe and fill with gravel.

It’s time to add your slotted pipe at the bottom of your trench. Install the pipe in the direction you want the water to flow. Shovel gravel on top of the pipe and cover it with another layer of landscape fabric. You can add soil or sod onto the landscape fabric to blend it with the rest of your yard. And now you’re done!

By the way, just in case you’re wondering, the name French drain doesn’t come from France. It’s from Henry French, a judge and farmer in Concord, Massachusetts, who promoted the idea in an 1859 book about farm drainage.