How much soil should be in the top of a French drain?

Once the drain line is installed, coarse stone or gravel should then be put on top of the drain line leaving approximately 3–4 inches for topsoil for the lawn to grow in.

Actually, most french drains that I am familiar with (for landscaping, not for house foundations) are not that deep. You WANT the water to get down into the drain. You can either just leave the area over the drain mulched or plant annuals or a groundcover, or better yet, just leave pea gravel on top.

Likewise, how close to the foundation should a French drain be? The trench should go in at least two feet below your substructure soil level. Digging the trench too close to the house can complicate your problems. A good rule of thumb is moving the drain one foot off the wall for each foot down you dig; for a four-foot deep drain, build it four feet from your walls.

Thereof, how long does a French drain need to be?

DIGGING A TRENCH FOR A FRENCH DRAIN First, a trench is dug with a slope in the direction you want the water to go; a slope of one inch for every eight feet in length is generally recommended.

Can I cover a French drain with dirt?

The simplest drain is a classic French drain, which is nothing more than a trench filled with coarse stone or gravel. The drain can be left open or, if aesthetics are a concern, can be covered with a couple of inches of topsoil and sod.

Can you put mulch over a French drain?

Since a French drain can be covered with turf or mulch after installation, it’s also virtually invisible. Though the traditional design simply was a gravel-filled trench, you’ll obtain far better results by employing a drainage pipe, landscaping fabric and a few high-tech tweaks.

Why is it called a French drain?

It’s from Henry French, a judge and farmer in Concord, Massachusetts, who promoted the idea in an 1859 book about farm drainage. French drains provide an easy channel for water to flow through. Water runs into a gravel-filled trench, then into perforated pipe at the bottom of the trench.

How wide should a French drain be?

A French drain starts with digging a trench. The depth and width of the trench can vary, but 5 to 6 inches wide and 8 to 12 inches deep are common sizes and usually satisfy most needs.

Does a French drain need to be sloped?

A French drain needs a slope of no less than 1%. That means from the highest point of the drain field all the way to the drain exit, the system should slope at least 1 inch for every 8 feet of length.

How do you put a French drain in your yard?

Installing French Drains 01:50 Dig a trench along the outside of your footing. Lay the pipe on the virgin soil. Cover the pipe with at least 12 inches of washed gravel. Lay filter fabric over the gravel to prevent any soil from clogging the pipe. Back-fill the foundation with top soil back to its original grade height.

How much gravel do I need for a 50 foot French drain?

French drain gravel should be washed three quarter inch minimum and as large as 1 ½ ” crushed stone. The upper 12 inches above the pipe shall be filled with native soil, to avoid having crushed stone over the perforated pipe that could damage the pipe.

Can you use landscape fabric for French drain?

Installing the Drainage Pipe and Gravel To make your French drain last a long, long time you need to use these following items: Clean or washed gravel (not crushed limestone – it becomes cement like) Permeable landscape fabric (they kind water passes through)

How do I know if my French drain is working?

How to Tell If the French Drain Is Working. The easiest way to tell if your French drain is operating properly is to look at your lawn or basement. If there’s water, chances are there could be a problem and your drain isn’t working correctly. This issue could be due to clogging.

Where does a French drain drain to?

It is used to direct surface water or groundwater away from a specific area, such as a home’s foundation. French drains direct surface level water toward the lowest point and allow it to seep through the surface level gravel into the drain.

Do French drains allow radon in?

jpope: Any open exposure to earth can allow radon gases to escape into the atmosphere. When you place a container (a house) over the exposed earth, the radon will be captured. “Footing or French drains” and radon have no direct relation.

Why do most yard drains fail?

One day that soil has all come together and there are no more air pockets. That’s the number one reason for yard drainage failures. And even if they’re using shovels, don’t let them put the dirt that they’re digging out back in. You have poor soil if you have a drainage problem.