How to Drain a French Tile Yard Drain

A sketch of a French drain with a protective housing over it.

Drainage problems near the house can be caused by poor grading and landscaping. The cost of re-grading is prohibitive, but flooding around the foundation can cause damage to the home and moisture in the basement.



A cheap and effective solution is a French drain. It can be in just a problem area or all around the house to divert water away from your foundation. Some French drains are little more than a deep trench filled with fine gravel. The trench is dug in the direction that slopes away from the house, in effect carrying excess water away from the foundation. These drains can get clogged with leaves and sediment just like a gutter, and need periodic maintenance.

Things You'll Need

• Gloves
• Shovel
• Level
• 0.5 to 1 inch size gravel
• 4 inch diameter perforated PVC drain piping
• Filter fabric
• Scissors
• Hacksaw
• Plumbers pipe compound
• PVC pipe elbow
• Pipe cap
• Coarse sand
• Turf or grass seed

Instructions

1. Assess the slope of your property. To work, the French drain needs to be installed so the flow of water goes away from the house. Determine a slope that will work, and dig an 8 inch deep by 5 inch wide trench. It should run from the problem area away from the home. Use the level to check that the trench contains at least a 0.5 percent slope away from the foundation.

2. Line the bottom of the trench with 1 or 2 inches of the gravel. Wrap pipe sections with filter fabric and lay the pipe in the trench. The fabric will help prevent debris from clogging up the perforated holes in the pipes.

3. Use the hacksaw to cut the pipe to the lengths needed and join them with pipe compound. Once the entire distance of the trench is lined with pipe, run the last section upward using an elbow pipe piece. Close the end with the cap so you can use the opening as a clean-out when necessary.

4. Add enough gravel around the pipe so that 1 inch of each of the sides is covered. Spread sand over the remaining space in the pipe, completely covering the pipes. Smooth out the sand and make it level with the surface of the soil if you are seeding. If you are laying sod, reduce the level of the sand to 1/2 inch below the soil level.

5. Cut pieces of turf and fill in the trench. Lay them on the top of the French drain and press them down firmly so they make contact with the sand. Keep the area moist by watering daily for at least two weeks.

6. Sow grass seed on top of the evenly smooth trench if you are not using sod. Sprinkle a fine coating of sand on top of the seed to protect it from blowing away. Keep the soil moist up to 2 inches until germination is achieved. Thereafter, water every other day until the grass is 2 inches high.

References

• Grounds Magazine: How to Install a French Drain
• Rain Barrel: What is a French Drain?
• Basement Repair: Exterior French Drains