Question: Can A French Drain Be Level?

How far should a foundation be from a French drain?

A French drain consists of buried perforated pipes slightly sloped to easily channel water flow, in this case, away from the house foundation.

Start by digging a 2-foot-deep-by-18-inch-wide trench 2 feet or so away from the foundation at the highest point where the rear yard meets the foundation..

How deep should a French drain be?

About 8 inches to 2 feetFrench 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 should a French drain 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.

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.

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

polypropylene soil fabricQuality woven, pure polypropylene soil fabric has always been preferred for French drains, soil stabilization, ditches, and pipe-in-gravel, chamber and mound septic leach field systems.

Can you 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.

Do French drains really work?

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.

Are French drains effective?

French drains are effective at removing moisture from over-saturated soil. … Additionally, French drains are susceptible to frequent clogging, as they are underground, and roots from trees and shrubs often displace and damage the perforated piping.

Can a French drain be too deep?

For a slab foundation, you want the pipe below the slab or about 2 feet. If you have a basement, you can install the French drain 6-feet deep or more depending on the depth of your basement.

Do holes go up or down in a French drain?

When you lay your PVC pipe, the rows of holes should always be facing the downward position. You want to keep the water level in your French drain as low as possible at all times, and you can’t achieve this if the holes are facing upwards or sideways.

What is the difference between a French drain and a trench drain?

Drainage systems are more than just holes in the soil. Trench and French styles are two effective approaches to move water offsite, but the difference between them is often misunderstood. … The defining difference is very simple, however: Trench drains are surface structures while French drains are subsurface ones.

Can you drive over a French drain?

A true French drain is made with gravel, but with gravel driveways, PVC piping is recommended. The PVC piping only needs to be 4 to 6 inches in diameter for draining purposes. It must also be rugged enough to withstand the weight of vehicles driving over it.

Does a French drain need to be sloped?

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.

Why do holes go down on French drain?

A review of installation instructions from several State DOT manuals reveals that the holes should be down (i.e. placed facing the bottom of the trench). The reason is that this allows the water to enter the pipe and drain from the soil at the lowest level.

How long does a French drain last?

approximately 30 to 40 yearsGenerally speaking, a French drain will last approximately 30 to 40 years.