What is the slope of a French drain?

1 percent

Dig a Trench



The trench should be about 18 inches deep and 9 to 12 inches wide. 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.

Will a French drain work on a hill?

Quote from the video:
Quote from Youtube video: Because there's no way an underground drain is going to work here an underground French drain. And riprap slows down that flow of water again. You can see it comes from way back there on the hill.

What does a French drain empty into?

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.

What is French drain system?

Basically, a French drain is a simple trench dug in the ground in the most problematic areas of the yard. The trench is filled with a perforated pipe wrapped in water-permeable fabric, and the pipe is covered with several layers of stone or gravel.

What slope do you need for water to drain?

¼ inch per foot

But do you know the proper slope? The ideal slope of any drain line is ¼ inch per foot of pipe. In other words, for every foot the pipe travels horizontally, it should be dropping ¼ inch vertically. Many drains either have too little slope or too much slope.

How far should a foundation be from a French drain?

We recommend installing the french drains between 2 and 5 feet away from the foundation. There are a few variables that impact the exact distance to dig the new drain lines to carry water away from your home. Finding the right distance: Check where water is pooling naturally during heavy rains.

Do french drains really work?

How Effective is a French Drain System? 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 the desired discharge point.

Does a French drain need to run downhill?

Quote from the video:
Quote from Youtube video: It can run uphill as long as the discharge is lower than the collection is this that simple.

Why are French drains used?

French drains are primarily used to prevent ground and surface water from penetrating or damaging building foundations and as an alternative to open ditches or storm sewers for streets and highways.

What is a French drain in a basement?

A French drain (also called a weeping tile, drain tile, perimeter drain or sub-surface drain) is a common basement waterproofing solution. It’s a trench containing a perforated pipe that redirects surface water and groundwater away from the foundation.

Why do I need French drain?

Operating under the natural tendency of water to run downhill, French drains are a simple yet effective way to reroute water and ensure your crawl space and belongings stay dry, or your yard and driveway are usable. Water flows into a ditch or trench that contains a perforated pipe, which is covered with gravel.

How deep are French drains?

About 8 inches to 2 feet deep

French drain depth: About 8 inches to 2 feet deep should be sufficient for many water-diverting projects, though related systems, such as those built around foundations and sub-ground living spaces, as well as the bases of retaining walls, may be deeper.

How do you create a slope for a drainage?

Calculate the slope: Each foot of elevation drop over a 100-foot length is 1 percent. Therefore, it takes 2 feet of elevation change over each 100-foot length of a swale to create a 2-percent slope. If the distance is 10 feet, you’ll need a fall of 0.2 feet (roughly 2.5 inches) to create a 2-percent slope.

What is the best pipe to use for a French drain?

PVC pipe

French drains are typically constructed with black corrugated pipe, but there are arguments that favor using white PVC pipe for the job, as well.

How long do French drains last?

approximately 30 to 40 years

Generally speaking, a French drain will last approximately 30 to 40 years. However, the above-mentioned factors may shorten its life cycle and it must then be replaced by a team of foundation experts.

Where does a French drain end?

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.

What are the different types of French drains?

There are several types of French drains, including surface French drains, blind French drains, and trench French drains. There are several types of trench drains, including channel drains, trench drains, and slot Drains.

Are french drains expensive?

On 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 French drain a house?

Quote from the video:
Quote from Youtube video: So because we're gonna bring our gravel to graves it's going to act like a channel drain. Water will come down the hill. And it's just going to drop through the gravel. Into our pipe. And so we want