Underground springs can lead to seepage into your basement causing you problems, such as high humidity, musty odors, fungi and unhealthy environment. When the seepage is serious, soil erosion may occur under the foundation causing your wall to crack or drop. To stop this, you can install French drains around the inside perimeter of the foundation wall. A French drain is a dug trench that captures sub-surface soil water and directs it away from the foundation.
Items you will need
Plastic drain pipe
Contact your local utility company a few days before you install your French drain. They will mark all the underground utility lines on your property, such as sewer, electric and phone lines that might be destroyed when digging the trenches.
Survey outside your house to determine which direction the French drain is going to flow. The drain should flow in an area that is lower and further than the foundation to prevent the water from flowing back.
Plan on what you will do with the dirt that will be left over after installing the French drain. Do not return much of the dirt into the trench because of the gravel.
Dig a trench using your desirable measurements but 5 inches to 6 inches wide and 8 inches to 12 inches deep are the common French drain sizes.
Use ground sheeting available at most builders’ merchants to line the trench. The ground sheeting is useful in keeping away dirt such as silt that might block the drain while allowing water to pass through.
Lay the plastic pipe in the dug trench sloping from a higher elevation starting point to a lower elevation ending point so that the water can be forced out by gravity.
Cover the trench with washed gravel and then wrap it with the ground sheeting. Finally, cover the drain with soil.
To avoid slowing down the flow of water, dig a trench that is as straight as possible.
- University of Tennessee: Wet Basement and Crawl Space Problems, Causes and Remedies — Tips for Homeowners and Home Buyers; Dr. Bruce, A. Tschantz; September 1997
- Easy Digging: How to Dig and Install a French Drain
- Life and Homes; French Drains Effective Option for Flooded Basement; Evie Parrish; March 2010
- "Grounds Maintenance"; How To: Install a French Drain; Eric Liskey
- GardenAdvice.co.uk: French Drains and Rear Wall Drainage
- HGTVPro.com: How to Install a French Drain