why do they call it a french drain

A French drain is a trench that is dug in the ground to collect and remove water. The French drain is called the French drain because it was originally invented by a Frenchman, Alphonse Guérin, who lived in Canada. He devised this method to deal with the terrible flooding problems that were plaguing his land.

Full Answer

What is a French drain and how does it work?

What Is A French Drain System, And How Does It Function? Simply put, a French drain helps collect and redirect water. Its design consists of a wide perforated pipe laid on the ground and covered with porous sand, gravel, or rock materials. To make such a drain efficiently direct water away, it needs to be angled downwards away from the area ...

What is the purpose of a French drain?

When to Use French Drain Systems

• Recurring Flooding and Foundation Damage. A weeping tile or interior French drain can be used to protect the basement from recurring floods and to prevent further damage to the foundation.
• Pooling Surface Water. ...
• Retaining Walls Under Pressure. ...

Why should you install French drains around foundations?

Your property may benefit from a French drain if:

• the soil is often soggy and standing water is common.
• the basement floods regularly.
• your yard includes a retaining wall on a hillside.

Do French drains work well?

Unfortunately, this fact oftentimes is overlooked. Properly constructed, french drains will work well to transmit water from the pipe to the exit of the pipe; however, they are not very efficient in dewatering poorly drained soils. Adequate fall means at least 2 ft lower per 100 ft of pipe or 0.25 in. per foot of slope.

Why is a drain called a French drain?

What Is a 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. Fascinated by agriculture, in 1859 French wrote a book, “Farm Drainage,” highlighting the drainage systems in use at the time.

What is the difference between a French drain and a regular 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. Here's a closer look at each type of drain.

What makes a French drain French?

But a French drain is nothing more than a ditch in sloped ground, inset with a perforated drain pipe under a layer of gravel.

What is the point of a French drain?

French Drains are primarily used to drain groundwater from gardens and around the foundations of buildings. French drains are designed to move water that is trapped in the ground away or towards an area. They are best used in soil that is prone to frequent saturation from rain or flooding.

Do French drains attract mosquitoes?

As great as french drains are for moving water, the water basins that serve as inlets are perfect breeding grounds for mosquitos. They are dark, wet, and usually undisturbed except during a rainfall.

Can you walk on a French drain?

Popular in the space between houses, drainage walkways are basically a stepping stone path installed over the top of a French drain system. They function much like a dry creek bed, but allow for walking on top.

How long do French drains last?

When enough sand, clay or silt gets past the fabric, the gravel spaces fill and the effectiveness of the french drain ends. 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 you put grass over a French drain?

0:503:10How Do You Grow Grass Over a French Drain? - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou can see we took two and a half inches of root with the turf. They do have sprinklers. So even inMoreYou can see we took two and a half inches of root with the turf. They do have sprinklers. So even in the drought they'll be able to keep this alive over the French drain system.

Can you run downspouts into French drain?

A French drain is actually a network of pipes laid in trenches dug beneath the ground through which water runoff can flow. This structure can be attached to your downspouts and will work seamlessly with your existing gutters.

Whats better than a French drain?

A sump pump is one the the most popular and most effective alternatives to a french drain. A sump pump add lots of drainage but comes with a few downsides. A sump system requires electricity to function and can be expensive to install and maintain.

Where does French drain water go?

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. This gravel also blocks the passage of excess debris.

What is the average cost of a French drain?

French drain cost runs anywhere from $500 to $18,000, with $5,000 being the national average. Modern building practices incorporate methods to direct rainwater away from a home's foundation.

Whats better than a French drain?

A sump pump is one the the most popular and most effective alternatives to a french drain. A sump pump add lots of drainage but comes with a few downsides. A sump system requires electricity to function and can be expensive to install and maintain.

Are French drains worth it?

French drains help prevent flooding and reduce the risk of long-term water damage to your property. They can last between 30 and 40 years. They're cost-effective. French drains can be aesthetically pleasing as they are usually covered with small rocks, plants and sometimes even decorative grates.

What does it cost to have a French drain installed?

between $5,000 and $13,500On average, homeowners can expect to pay between $5,000 and $13,500 to have a French drain installed in the home. The required size of the drain will also play a role in the cost—most basements will need between 100 and 150 feet of installed French drain.

How do you know if you have a French drain?

You can always consult a professional, but below are some sure signs that indicate you needing a French drain:Water In Your Crawl Space. Having water in your crawl space can end up damaging the items in your home, and even your house itself. ... Flooded/Soggy Backyard or Driveway. ... Constructing A Retaining Wall.

What is a French drain?

A French drain or weeping tile (also trench drain, filter drain, blind drain, rubble drain, rock drain, drain tile, perimeter drain, land drain, French ditch, sub-surface drain, sub-soil drain or agricultural drain) is a trench filled with gravel or rock or containing a perforated pipe that redirects surface water and groundwater away from an area.

How do French drains work?

Ditches are dug manually or by a trencher. An inclination of 1 in 100 to 1 in 200 is typical. Lining the bottom of the ditch with clay or plastic pipe increases the volume of water that can flow through the drain. Modern French drain systems are made of perforated pipe, i. e., weeping tile surrounded by sand or gravel, and geotextile or landscaping textile. Landscaping textiles prevent migration of the drainage material and also prevent soil and roots from entering and clogging the pipe. The perforated pipe provides a minor subterranean volume of storage for water, yet the prime purpose is drainage of the area along the full length of the pipe via its perforations and to discharge any surplus water at its terminus. The direction of percolation depends on the relative conditions within and without the pipe.

What is a curtain drain?

This form comprises a perforated pipe surrounded by gravel. It is similar to the traditional French drain, the gravel or aggregate material of which extends to the surface of the ground and is uncovered to permit collection of water, except that a curtain drain does not extend to the surface and instead is covered by soil, in which turf grass or other vegetation may be planted, so that the drain is concealed.

What is an interceptor drain?

This form combines drainage of groundwater and interception of surface water or run off water, and may connect into the underground pipes so as to rapidly divert surface water; it preferably has a cleanable filter to avoid migration of surface debris to the subterranean area that would clog the pipes. Interceptor drain.

How long is a perforated pipe?

The length is 200 mm (7.9 in). This form is less expensive to build than a traditional French drain.

Where were drains invented?

These may have been invented in France but Henry Flagg French (1813–1885) of Concord, Massachusetts, a lawyer and Assistant US Treasury Secretary described and popularised them in Farm Drainage (1859). French's own drains were made of sections of ordinary roofing tile that were laid with a 1⁄8 in (0.32 cm) gap in between the sections to admit water. Later, specialised drain tiles were designed with perforations. To prevent clogging, the size of the gravel varied from coarse in the center to fine on the outside and was selected contingent on the gradation of the surrounding soil. The sizes of particles were critical to prevent the surrounding soil from washing into the pores, i. e., voids between the particles of gravel and thereby clogging the drain. The later development of geotextiles greatly simplified this technique.

How many underground pipes are there in a French drain?

Depending on the expected level and volume of rain water or runoff, French drains can be widened or also founded on 2 or 3 underground drain pipes.

What is a French drain?

A French drain is a trench, lined with gravel or small rocks, which is designed to direct water away from an area through a perforated pipe. A French drain can help property owners to prevent water from pooling within their yards. It’s a drainage solution that, despite everything implied by the name, has nothing to do with France.

When You Need a French Drain?

If you’re having any major flooding problem on your property, then a French drain may be the solution for you. Not only is it an effective draining solution, but it won’t detract from the overall appearance of your home and lawn. Consider a French drain if you’re dealing with one of the following situations:

What happens when it rains on a French drain?

During heavy rain, water from the ground will rise and enter the pipe of your French drain. Since the trench is sloped downward, the groundwater will naturally flow to the end of the drain until it’s safely off your property. When planning your French drain, be sure to double-check that the pipe will lead the water to a sewer or some other kind of appropriate drainage destination.

Why add a French drain to your home?

By adding a French drain to your home, you can direct excess water off your property and away from your patio. Keeping your patio and yard dry will also prevent mosquitos and other pests from breeding right by your home.

What to put on top of a French drain?

Once the trench is constructed, you have the choice to put sod, gravel, or other rocks on top until the entire trench is level with the rest of the yard. One important thing to note about the functionality of a French drain is that the holes in the piping need to be on the bottom. The holes will allow water that rises from the ground, to drain faster.

Can you use a French drain for surface water?

Be sure to install a French drain that is suited to the specific problem that you’re having on your property. For example, surface water drainage can be provided by a shallow French drain. More extreme groundwater flooding is best managed using a deep French drain. Consult with a professional before attempting to add a French drain to your property, as this will yield the best possible results.

Can a French drain be installed in a basement?

While foundation damage may not be the easiest to spot, a French drain can do wonders for preventing it in the first place. It can end up saving you hundreds of dollars in damages that would happen as a result of water harming your home’s foundation and getting into your basement. Install one so that you can prevent floodwater from ever reaching your home.

How Does a French Drain Work?

French drains work by giving water a path of least resistance to flow through. Water will first enter a trench filled with gravel, then through a perforated pipe, then off into an area away from your yard or home. Trench bottoms are typically sloped 1 inch for every 8 feet you want the water to travel. Most homeowners will choose to divert the water to one of the following: a low-lying portion of your yard, a drainage ditch, a well, or the street.

Why do you need a French drain?

Why Would You Need a French Drain? 1 You have standing water after most rainstorms 2 You have a problem with surface water, like a driveway that is washing out or a lawn that is always soggy 3 You have flooding in your basement or home 4 You are planning to build a retaining wall on the side of a hill

Why are French drains so popular?

French drains are popular because they are incredibly effective drainage tools. Beyond the general need for a drainage system, why might you need a french drain?

What Type of French Drain Should You Choose?

If your problem is surface water, choose a shallow french drain or curtain drain that is located uphill of the area you want to stay dry. This location will prevent water from continuing to flow downhill. If you are trying to prevent water from entering your basement, install a deep french drain or footlong drain that runs along your house and stops water from getting below ground. If you are building a hillside retaining wall, use a french drain wherever you plan on having the first set of blocks or stones to prevent water from building up underneath or behind the retaining wall.

What Is A French Drain?

A French Drain is a pipe that collects and directs water. A wide, perforated pipe placed in the ground collects excess water and drains it away from the affected area. The pipe is covered with gravel or rock so that it’s not visible, and it’s angled downward to make sure drainage is smooth.

Why is my French drain angled downward?

The pipe is covered with gravel or rock so that it’s not visible, and it’s angled downward to make sure drainage is smooth. Open ditches and stormwater drains manage rain-flow and excess water near roads, but you don’t want an open ditch near your building or house. A French Drain system is less open, but still allows water to drain ...

What is a collector and interceptor drain?

Collector and Interceptor drains direct groundwater and surface run-off towards the same drain. It quickly handles surface water to prevent flooding or ground upheaval, but should have a filter because of the shifting earth and debris. Otherwise, you have problems with the pipe further down the line.

Can you nick a gas line while burying a French drain?

Nicking a gas line or sewage pipe while you’re burying a French Drain can cost you a chunk of change to fix and ruin the goodwill of your neighbors.

Do all French drains look the same?

Not all French Drains look the same. Depending on your needs, you have a few options. Traditional French Drains, sometimes called Curtain Drains, follow the directions above. They use gravel and perforated pipe to collect water and it’s covered in earth and vegetation. They’re the least obstructive.

Can I Install A French Drain Myself?

We are huge fans of DIY, but we recommend you call a professional to install a French Drain. Here’s 4 reasons why it is important to find a professional you can trust:

WHAT IS A FRENCH DRAIN?

It sounds elegant but in reality, it’s nothing more sophisticated than a gravel-lined ditch with an embedded pipe that carries water away from the home.

How do French drains work?

Counterintuitive though it may be, French drains work by allowing water to flow into them from below. Wrap landscaping fabric around the pipe to keep dirt and roots from obstructing the system.

What is the difference between PVC and flexible drain pipe?

PVC lasts longer, and if you encounter a clog, it can be cleaned with pressure or a plumber’s snake. Flexible pipe , on the other hand, is less expensive and easier to work with. Advertisement.

How deep should a French drain be?

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. If you’re installing a French drain around your foundation to prevent basement moisture, take care to position the pipe below slab or finished floor level.

Can you wrap a pipe with landscaping fabric?

Instead of wrapping pipe with landscaping fabric, you can buy a flexible perforated pipe that comes encased in water-permeable fabric.

Overview

History and construction

Permitting

Gallery

See also

External links