How to Install a French Drain

A good home is one with proper drainage system to keep the environment dry and mold-free. With this system in place, water can flow to where it should go and therefore keep your home in good shape.

A French drain system is one of the most commonly used today to solve water flow problems in residential areas. This involves the use of slotted pipes, filter fabric and gravel. Unlike in the olden days, the fabric and gravel are now additional components to prevent the clogging of sand and soil going forward.

To install a French drain, you have two options for the pipes to use. Either the perforated drainage pipes wherein water can come and go through the small openings or the slotted pipes which are better at reducing the chances of fine soil particles getting into the pipe.

Since this is going to be a drainage system, digging a trench will have to be the very first important step. But before you do so, plot out the trench lines. Then choose an area with sandy soil and dig a trench at least 2 feet wide and at your preferred depth. It can be 6 feet deep for a basement or a shallower one for other areas.

It’s important to note, though, that you have to be aware first of the city codes in your area concerning digging. This is to ensure that you do not violate any code and most importantly, the French drain you’re installing won’t have any adverse effect on the land of your neighbor.

The laying of the pipe on the soil follows the digging. Always remember that for a drainage to work well, the pipe has to be in a sloping position where the starting point is higher than the end part to allow water to flow out properly. The direction of the slope should be away from the house to keep prevent stagnant water and moisture. For the position of the slope, a drop of one foot is recommended for every 100 feet of length while the others consider a drop of six inches as ideal.

Next, use washed gravel or small pieces of rock at least 12 inches in height to cover the pipe. Then on top of this gravel, lay the filter fabric. This will prevent any soil from going into the pipe and clogging it.

From there, you can now put the topsoil back to its original grade position. And you’re done. That’s easy.

This installation process can be quite labor intensive especially the digging part. You may want to consider hiring a professional to do the entire job for you or just a backhoe operator to dig the French drain if you want to have a hand in the pipe installation. Another option available is to rent trenchers which are machines that can cut thin trenches. This will save you on cost.

Additionally, you can consult a surveyor in you doubt about the grading for your French drain. This professional may also be able to help you find the best area to channel your water.