How do you install French drains in a basement?

Installing a French drain requires digging a trench along the outside of the footing and laying the pipe in the soil. Cover the pipe and lay filter fabric over the gravel. Back-fill the foundation and level it off.

Installing a French drain is an effective way of taking care of basement flooding problems. French drains can be installed either inside or outside and each takes a couple of days to complete. Experts recommend hiring a professional to do the work, but experienced DIY homeowners may be able to tackle the job with little trouble. However, the cost for installing an internal French drain runs from $3,000 to $4,000 and an external drain costs from $9,000 to $15,000, as of 2015. The external drain is generally the most effective type.

1. Mark the location

Decide where the French drain should be and mark the location with striping spray paint.

2. Start digging

Using the spray-painted marks, start digging a trench that is six inches wide.

3. Add gravel

After digging, add three inches of gravel to the trench.

4. Add a fabric liner

Add landscaping fabric to the entire length of the trench on top of the gravel. Leave around 10 inches of fabric on each side.

5. Lay the pipe

Lay the pipe on top of the landscape fabric.

6. Cover with gravel

Cover the pipe completely with gravel, leaving around five inches between the top of the gravel and the ground.

7. Fold over the fabric

Fold the excess fabric over the top of the pipe.

8. Cover the trench

Fill and cover the trench with sand, and then topsoil.