Table of Contents
A French drain is a trench filled with a perforated pipe and gravel that allows water to drain naturally from your yard. Depending on the size of your yard and the scale of your drainage issue, you can purchase the pipes and equipment to create a French drain yourself.
What is the difference between a yard drain and a French drain?
The main difference between the two is that French drains capture and remove groundwater while trench drains quickly remove surface water before it can saturate the ground.
How do French drains work in yard?
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. Water travels freely through the pipe, which empties a safe distance from the house.
How do you tell if you have a French drain?
French drains are designed to collect rainwater and channel it downhill. If surface water is standing in low areas of the yard that are supposed to flow into your French drain, you have a drainage problem. If the low areas of your yard are as firm and dry as higher spots, then your French drain is working as expected.
Where do French drains drain to?
These drains are 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.
How much should a French drain cost per foot?
According to Fixr, the average French drain costs $4,500. An exterior drain located fairly close to the surface could cost as little as $1,000, or $25 per linear foot on average. Drains installed under your basement floor could cost $2,000 or more. Expect to pay $60 to $70 per linear foot for installation.
Is a French drain a good idea?
French drain systems are incredibly effective because, unlike typical surface drains, they collect water over the entire length of the drain as opposed to one dedicated area. The force of gravity helps to guide water along a reliably smooth path to a desired discharge point.
Why do french drains fail?
Over time, a French drain may become clogged. Tiny soil and clay granules slip through the pores of the landscape fabric and gradually build up inside the pipe. Another common cause of French drain clogs is root intrusion from grass, shrubs, and trees.
How long do french drains last?
Generally speaking, a French drain will last approximately 30 to 40 years.
Does French drain need an outlet?
A properly designed French drain system does not require an outlet. The water will simply soak into the soil as it flows along the perforated pipe. In fact, a French drain doesn’t require an inlet on just one end either.
Why would you need a French drain?
If you are facing recurrent drainage issues on your property, you may need a French drain to effectively remove that excess water and get it away from your foundation. Avoiding damage to your property, particularly your foundation and basement, is the main purpose of a French drain.
How shallow can a French drain be?
DIGGING A TRENCH FOR A FRENCH DRAIN Because there is a direct relationship between the diameter of a drain pipe and its relative effectiveness, make your trench no smaller than 12 inches wide, and aim for a depth between 18 and 24 inches.
What is at the end of a French drain?
The two ends of a French drain system are: The drain field, or high end, where excess ground water enters the drain pipes. The drain exit, or lowest point, where water leaves the system.
Why is it called French drain?
While you might think that the French drain originated in France, the name derives from its inventor, Henry Flagg French, a farmer from New England born in 1813. Today, it’s known as the French drain. A French drain consists of an excavated trench with gravel sides and a perforated pipe to carry the water.
Does a French drain need a slope?
French drains need to have a slope of at least 1 percent, so the force of gravity will work for you. This means that the drain should slope down a total of at least one inch for every 10 feet of pipe.
How big of a French drain do I need?
A suitable pipe for most residential French drain systems has a 4-inch diameter. Larger 6- or 8-inch pipes may be utilized, but are most suitable for areas where there is a high volume of water that must be drained quickly.
Which is better French drain or catch basin?
If you are trying to control moderate amounts of runoff and groundwater over a large area, install a French drain. To drain large amounts of runoff or surface area from a low spot in your yard, install a catch basin.
What’s better than a French drain?
Swales or Valleys Swales, also called valleys, are an alternative to French drains that capture and divert rainwater. Swales are shallow ditches that do not contain pipes. You can usually find them along a property’s edge, following the natural grade of the land to direct runoff to ditches or wooded areas.
Can you plant trees over a French 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.
How often replace French drain?
This is why most experts state that a French drain is not a long-term solution to a drainage problem: You have to dig it up and reinstall it every eight to 10 years.
Can a French drain get clogged?
But, just like any other type of drain, French drains are susceptible to clogging. Soil and debris have a tendency to build up inside the pipes, eventually stopping water from flowing altogether. To avoid letting water back up into your home, follow this French drain cleaning guide.
How close to the house should a French drain be?
How Close Should a French Drain be to the House? A good rule of thumb is to install french drains 3 feet from the house. Make sure to measure around the porch, patio and deck.
Can you cover a French drain with dirt?
Can I cover a French drain with dirt? Because a French drain has holes throughout the pipe which allow it collect water, you should not install dirt on top of the drain pipe. Installing dirt will clog the pipe and the holes, rendering it useless.
