French Drain Installation and Home Foundations

Installing a French drain is a good way of protecting your home from water damage.  A French drain, sometimes called a weeping tile or a blind drain, is a type of trench that’s filled with gravel or has a perforated pipe that helps redirect water away from your home’s foundation.

The perforations can be either small circles or slots, but the slotted pipes are actually recommended because they don’t allow as much soil into the pipe.

While French drains are often used to help prevent water from seeping into a building’s foundation, they do have other uses, such as helping redistribute water or relieve water pressure.

There are several different variations on the French drain that may be used.  The filter drain is most often used to protect the foundations of houses.  If the flooding in the area is really bad, interceptor or collector variations may be used.  These help to collect both groundwater and surface water and carry them away from the foundation.

Drain Installation and Placement

When French drains are installed, they should always be installed near or around the foundation.  They’re fairly easy to install, but it’s still a good idea to have a licensed professional install them just to make certain that they’re set correctly.  Otherwise, you may find that the water doesn’t drain away quite like it should.

-The French drain has to be installed several dozen inches or more in the soil around the house.
-The perforated drain pipe is installed first, then covered by some washed gravel fill.
-This helps filter the water in the soil down into the pipe.
-Once the water is collected in the pipes, it’s directed away from the foundation and the house.

Some homes won’t really need French drains, especially if they’re on relatively flat land or if they’re built on top of a slope.
However, if your house is built on the lower end of a slope, water may often collect around your foundation.  This is where a French drain can come in very handy.  The soil may not be able to absorb all of the water, which means it may start leaking into the foundation, the crawl space, or even your basement.

How a French Drain Can Help

Water damage can be very difficult to detect at first, especially if you rarely go into your crawlspace, but once it’s noticed, it’s usually fairly extensive and expensive to repair.  A French drain will prevent this since it will help carry away a good amount of the water from the edge of your house.

There are a few things to remember when installing a French drain:  The trench can be dug fairly deep (six feet or more), but it needs to be at least two feet deep for a home built on a slab.  The perforated pipe always needs to slope downward from the starting point so gravity can help force the water downward and away from the home.

The piping should be covered by about 12 inches of washed gravel at a minimum.  If it’s installed correctly, you’ll find that water no longer seeps into your home’s foundation or basement, keeping it safe from water damage.