French | Lasting Impressions Landscape


French drains are a common drainage systems, which are designed to remove water that is accumulating below the surface.  French drains are very good at collecting water that is accumulating in marshy or boggy areas that have been created by overwatering or poor drainage. They are primarily used to prevent ground and surface water from penetrating or damaging building foundations and retaining walls to relieve ground water pressure.

A French Drain is a trench covered with gravel or rock or containing a perforated pipe that redirects surface and groundwater away from an area. A French drain can have perforated hollow pipes along the bottom (see images) to quickly vent water that seeps down through the upper gravel or rock. Either the entire trench is lined with filter fabric, or the pipe is wrapped in filter fabric. If the trench for a French drain is lined with filter cloth, the drain will last for many years.  If only the pipe is wrapped in filter cloth, soil will wash into the gravel in just a few years.

We start with digging a trench and grade it so the bottom is flat and evenly sloped.  Next, we line the trench with filter fabric.  After the fabric is placed, 1 to 2 inches of gravel is placed in the bottom of the trench. A perforated pipe is then laid on the gravel.  The trench filled to a level 4 to 6 inches below the surface and the edges of the filter fabric are laid over the top of the gravel.  Finally, the top of the trench is filled with soil.

Our French drains can either work with gravity, if enough of a slope available, or be connected to sump pumps depending on your need. We never connect them to downspouts since the purpose of a French drain is to get rid of subsurface water.  If you fill up a French drain with water by overloading it, you can cause serious damage to your home or business.