Drains and Plumbing

Learn to Design, Build and Install a French Drain Yourself.

Okay, the truth is, there's not much that's sexy about drains. But when your basement is wet and you can't get to the freezer because it's floating somewhere below the stairs, you're going to thrill to the sound of the words "French drain". French drains may have gotten their names because originally, they were made without the use of any pipes or lines葉hey were a simply ditch construction with gravel, which led water away from houses on the city streets and to places where it would do less harm.
If you've ever read about Paris in the 1930s, you will have an understanding of the French drain葉he sewers of Paris were known worldwide for being nothing more than open trenches filled with human waste. Not too classy for the most elegant city on earth!

But these days even Paris has succumbed to the lure of inastalling pipes and wastewater management, and the open sewer is just a rank memory in all but the worst of slums. Building a french drain remain widely useful, although not for sewage葉hey are perfect for diverting rainwater from foundations, basements, driveways and other places you would rather keep dry. French drains can in some cases be installed without pipes, by laying beds of gravel down in trenches under the topsoil, but for most building codes and to keep the water moving right where you want it, laying in a series of pipes makes the most sense.

Flooding occurs when the topsoil, which contains a lot of air, becomes saturated with water. If the area isn't level, the water will flow downhill; if there's no slope, it will stand where it is, taking a long time to work its way into the more compacted and often clayey soils beneath. Water that would normally flow downhill in a sheet of liquid topsoil finds it much easier to move through gravel and pipe, so it will naturally find its way into your trench.

If the slope in your yard isn't perfectly obvious, rent a builder's level to help you find the high and low points in the area you want to design a drain. Your yard may look fairly flat, but sometimes, although the slope isn't apparent to the naked eye, it's sufficient to send water on its way downhill. A level will help you find the lowest part of your property, which is where you'll want your pipe to exit the ground.

You can control flooding around your house by digging a narrow trench about 6 inches wide and about 2 feet deep that wraps around three sides of your house and heads downhill. Dig the trenches in a U shape around your house, keeping the ditch between four and six feet from the foundation of your house. Once you have your trench dug, compact the earth in the bottom of it, and place your drainage pipe into the trench. Make sure the holes in the drain pipe are pointing down into the soil, or your trench won't work because the holes will be immediately clogged with dirt. This is really important様ots of people doe everything right but then screw up the pipe by putting it in upside down, so their trenches never work. Point the holes down!

Once you have the pipe installed, cover it with 1 inch (or greater) washed, rounded gravel, filling the trench until it's one inch from the surface of the ground. You can then place a strip of sod or soil planted with grass seed over the trench to make it look nice and help keep the gravel in place. If you have problems not just with sub-surface water but with water standing on top of the ground as well, you can just fill the trench all the way to the top with gravel: this will increase your drainage. If the sight of the trench will bother you, you can make it wider at the top and put some curves into it when you're planning its course, so that the gravel becomes a winding path.

You don't need tons of expensive equipment to install a French drain system. Any time you're planning to dig into the ground, you should start by making sure there are no underground utility lines in the area you're planning to trench. Buried electric cables, sewer or gas lines can kill you if you dig into them. At the very least, you may cut into a sewer line and make a big, expensive mess. So, make sure you know there's nothing else buried before you start to dig!

You can rent a ditch digger or trencher (also called the Ditch Witch) from a place that rents building supplies, and you can buy the perforated drainage pipe from most hardware or home supply stores. The builder's level is also something you can rent, and you can either pay to have the gravel delivered, or if you have access to a good sized truck, you can buy it much, much cheaper if you pick it up yourself. If you're not confident in your ability to calculate the amount of gravel you'll need, take the measurements of your trench (6 inches wide, 24 inches deep, 200 feet long, for example) to the place where you buy gravel and ask someone who works there to help you calculate the amount of gravel you need to buy. (This is good advice if you're near a building supply store that's not one of the huge chains: too many of the giant home stores employ teenagers who don't have a clue about how to help you.)

What's a Trench Drain?

You may hear the words "trench drain" and "French drain" used interchangeably, which can be confusing when you're contemplating at home drain repairs. "Trench drain" means different things to different people, for the lay person, it's a drain that's constructed by digging a ditch or trench and either laying gravel, pipes or both into the drain. Trenches are used in creating French drains, which are ideal for draining water away from houses or from land into storm sewers, catchments or other areas where the water won't pose as much of a problem. But to experts, trench drains may mean large, industrial drain systems that are built with trenches miles long and a hundred or more feet deep. Used in road building, city sewer systems and municipal drainage, trench drains are often the foundations on which entire cities rest.

Bookmark this page
(or type Ctrl + D)
Email this page to a friend

Natural Drain Cleaner for Clogged Drains

The first thing you need to know before working on a clogged drain is that the drain cleaners you see advertised on TV or on the supermarket shelves are made of dangerous chemicals that will eat through rubber gloves, skin, certain kinds of pipe, wood and anything else they touch. If their fumes are inhaled, they can cause damage to the lungs, nose and mouth. If they are eaten, they will kill, even in small amounts. Even when they are used "properly", they can ruin septic systems, pollute groundwater, and destroy pipes.

For a more healthy and safe alternative, try a natural drain cleaner, such as Drainbo, that is made from natually occuring bacteria that will fix a clogged drain, but won't hurt your drain pipes or the environment.

 Drain & Plumbing Resources
Drain Cleaner
Drain Openers
Septic Systems
Basic Drainage Systems
Drain Cleaning & Home Repair


Return Home

Continue reading the next drains and plumbing article on Sink Drains.

 Drains and Plumbing | Plumbing Directory
 Copyright (c) 2005 - 2021 Drains and Plumbing. All rights reserved.