How To Install a French Drain

French drains are like French fries – there’s really nothing about them that’s inherently French, and not too many people remember why they’re named the way they are. In France, they call French fries pommes frites – literally, “fried potatoes.” The French term for a French drain notwithstanding, the French drain is almost certainly as an effective method of water removal in Europe as it is in North America.

A classic shallow drainage system, the French drain is often the best and simplest start to a complete basement waterproofing campaign. Keeping a dry basement should be a top priority for every homeowner, as excessive basement moisture could result in a cracked foundation or a severe black mold buildup.

A French drain is an easy way to avoid a wet basement. You may be able to install one yourself, but hiring a basement waterproofing contractor might be the best way to go, particularly if you’re covering a wide tract of land, or if the system must be installed in the basement crawlspace itself or under the foundation.

Here’s the process to installing a French drain, outlined in a few easy steps.

Determine the drainage path. This is where you find out whether the job is simple enough to do yourself, or you need a basement waterproofing company to do the job for you. Start from the spot where water is collecting, or where you want to relieve flooding. This could be inside your basement or along your foundation. Then trace a route to the lowest part of your property, or a retention pond if you have one. Remember that the system needs at least a one percent grade to drain water effectively. The only physical principal involved here is gravity, so be sure to keep it in mind at all times. Be careful: There may be tree roots, other buildings, concrete pathways or underground utilities in your path.

Excavate the trench. Think of it as a moat around a medieval castle – only instead of keeping out foreign invaders, the trench in a French drain is meant to carry water away from your home. Dig the trench in a U shape, about six inches wide by a eight to 12 inches deep – though your measurements may vary depending on the size of your flooding problem.

Fill the trench. Lay about two inches of gravel in the trench, leaving enough room to lay pipe on top, then another layer of gravel above that. Again, how much gravel you use will depend on the depth of your trench and the extent of the area to be drained.

Lay the pipe. The pipe is the most important aspect of your French drain. In the area to be drained, you’ll need perforated pipe, so the water can enter the drainage system. But once you get past the flooded area, you’ll switch to a solid drain pipe, so the water doesn’t leak from the system.

Cover the pipe with gravel. It’s important to use gravel in a French drain system, and not just back-fill the trench with dirt, because creating a porous system through which water can escape is paramount. If you covered the pipe with dirt, it would just turn to mud once another flood came along, and be carried out through the system – or clog it. Stick to washed gravel or very coarse sand.

Sod over the unperforated portion of pipe. This can easily be hidden from view with sod, since its purpose isn’t to collect water but to carry it away.

A French drain is the simplest and most direct solution for relieving flooding in any area of your home, whether it’s the basement, around the foundation, or a low-lying area in your yard. Just like the mustard, Whether it’s actually French or not isn’t important – what’s important is that it works.

Right Way Waterproofing serves clients with basement waterproofing, basement remodeling and mold remediation needs in throughout the Delaware Valley, in Philadelphia, Delaware and New Jersey, throughout Bucks County, Montgomery County, Chester County, Burlington County, Mercer County and Delaware County, including Langhorne, Newtown, Yardley, Bensalem, Warminster, Morrisville, Lower Makefield, Trenton, Newark, Wilmington, King of Prussia, Newtown Square, the Main Line and Bala Cynwyd.