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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.
Why they call it French drain?
In the USA, this type of drain was named after Henry Flagg French, the man who invented it and wrote a book about farm drainage published in Massachusetts in 1859. French drains were initially used to reroute water from a sloping piece of land, to where the water could be used somewhere else.
What does the term French drain mean?
Definition of French drain : a drain consisting of an underground passage made by filling a trench with loose stones and covering with earth. — called also rubble drain.
What is the difference between a French drain and a trench drain?
Aside from what we’ve listed here, the difference between a French drain and a trench drain is that a French drain is used for water that is underground while a trench drain diverts excess water from a surface.
What is the difference between a surface drain and a French drain?
The primary difference between the two systems is that French drains are used for water that is gradually seeping below ground level while surface drains handle water that’s collecting above the ground. Their installation methods and materials also vary.
Why are French drains perforated?
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.
What is a drainage ditch called?
Like a trench drain, a swale is a surface water drainage device. However, it’s a lot more subtle in terms of its appearance in the landscape. A swale is like a ditch but it’s broad and shallow, and usually covered or lined with turfgrass or other vegetation.
What is another name for a French drain?
All these terms describe the same basic drain system: a French drain is also known as a blind drain, rubble drain, rock drain, drain tile or French tile. The structure of a French drain is a perforated pipe, surrounded by gravel in a trench.
Who invented the 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.
Where do French drains end?
Which End is Up? 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.
Which is better French drain or swale?
French drains have a more functional purpose, as they are intended to keep water away from the foundation. Swales, on the other hand, are often recommended by landscapers as a general-purpose drain. Swales are sometimes not an option in urban areas because they require large lots to shape properly.
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 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.
Will French drain catch surface water?
Ideal for landscapes and lawns, hardscape patios and driveways, retaining walls, and foundation and footing perimeters, French drains are used to direct surface water or groundwater away from a specific area toward the lowest point.
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.
How do I know if I 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.
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.
Do the holes go up or down on a French drain?
So, when installing a French drain, the holes in PVC piping always face the upward position. The only time holes should be in the downward position is when installing a leaching field. This is when water is poured or pumped into a pipe and we want the water to drain out of the pipe into the surrounding ground.
Why do they put rocks in ditches?
Lining drainage ditches with rocks creates a drainage system called French drains. The rocks are used to allow for greater drawing of water from the source area where the water was pooling. The water will flow into the rocks instead of being absorbed into the surrounding soil.
What is swale drainage?
A grass drainage swale is an open channel that collects water from hard surfaces and allows it to percolate into the ground, reducing the amount of runoff leaving the road or property. The grass covering the side slopes and swale bottom provides a filtration surface for the water and helps to reduce the flow velocity.
What is a swell in a yard?
Swales are broad, shallow ditches people use to help drain their yards of excess water. This way they can make the most of their outdoor area without having to wear boots or galoshes.
