Soggy yard or wet basement? French drains might be the solution to your problem. Here’s some information about how they function, if/when you need them, and different options you have.

Water tends to flow downhill down the easiest path possible, and this is the concept behind French Drains. Here you will use a slightly sloped-trench which is filled with gravel and water moves away from your home. The drain’s name isn’t from the country, but after Henry French (a farmer and judge) from MA. He promoted this idea in 1859 in a book about drainage.

How it works –

These drains offer a simple channel for water to flow through, where water and gravel filled trenches move through a perforated pipe away from your home. The water travels away from your home, and is deposited a safe distance away from it. The slope should be placed about 1” for every 8′ of direction you want the water to travel. The water can be moved to:

  • A low lying area on your property or drain ditch.
  • A dry well or the street.

When should you choose a French drain system? –

If a soggy driveway or problems with surface water are an issue, you might want to consider these drains. If water is making its way into the basement, or if you are building or renting a home on the hillside, using this drain is a viable solution.

If surface water is the problem –

Here you’ll place a shallow drain. Its also known as a curtain drain, and it will extend horizontally through your property. It goes directly uphill to the areas you will dry out and intercepts water in soggy areas. It doesn’t need to be too large, a typical size is 2 ft deep and 1.5 ft across. If passing through areas where tree shrubs are present, use solid pipes to eliminate the possibility of root growth and clogging.
Water in the basement? –

Here you’ll go with a deeper French drain system. This footing drain will run your home’s perimeter, over footing level, and will intercept water entering your basement. During construction it is easier to install than after the home is built. If basement walls are high, you will dig pretty deep to provide sufficient protection to the basement with the drains. If you have landscaping decks or walkways, this will further add to the expense, and the amount of time it will take to install these drains.

If a sufficient slope isn’t present, you might have to pipe the water and use a sump pump to lift it and move it to a storm drain system.

Interior Drain –

The interior French drain will intercept water flow as it is entering the basement, keeping the area dry. If the basement is finished, you will first have to remove the walls to complete this project. If there isn’t water running in the basement, this won’t be a problem.

A crew will cut channels throughout the home’s perimeter, chip concrete, and install the new pipe. Water will flow down to collection tanks, and sump pumps will move it towards the home’s drain. Channels are then patched with concrete, except for the small gap where water dribbles are caught at the base.

On a hillside –

If you are constructing a retaining wall, you want to add the drains behind the first course of blocks/stones. If not, water would make its way behind the wall and compromise its integrity. You should rest a pipe on the compact gravel base or on any concrete floors which are supporting the wall’s structure. This provides more integrity and strength to the project which you are completing on the hillside.

To protect clogging with silt, you will drape a landscape cloth along the base of the drain system. You will also place this cloth up the slope area, and drain gravel to help prevent water leaks or clogs to occur with your French drain system. At wall’s top portion, you will simply fold down the cloth, on the gravel base, and you will then cover the top portion with a few inches of soil. This provides stability to the structure, and also allows you to cover the cloth you placed over the drain system for a more natural look and finish.

If you think you may need to have a French Drain installed, be sure to call a Licensed French Drain Expert