How to Install French Drains

Divert groundwater from the basement or foundation with the help of gravel and fabric.
BPF_original_french-drain-step-7c_h

BPF_original_french-drain-step-7c_h

Good drainage is important to ensure that a home stays dry and free of mold. If groundwater collects in the basement, it is not only an inconvenient eyesore for the homeowner, it can also lead to wood rot and mold.

The most reliable way to eliminate undesirable, free-standing water is to install French drains with slotted pipes, filter fabric and gravel. The old way of installing French drains is to do it without the gravel and the fabric. Without the gravel and the fabric, however, the drain can clog up with sand and soil over time.

Installing French Drains 01:50

Install French drains properly and you can eliminate freestanding water.

The best practice for installing French drains is to use perforated drainage pipes, which allow water to enter or exit through small openings along the pipe. The perforations can be circles or slots. But slotted pipes are better than pipes with small round holes because they tend to reduce the amount of fine soil particles that get into the pipe.

Here's how to do it:

  • Dig a trench along the outside of your footing. The trench should be at least 2 feet wide, and can be as deep as 6 feet for a basement or as shallow as two feet for a slab-on-grade home.
  • Lay the pipe on the virgin soil. It is very important that the pipe always be sloped from a higher starting point to an ending point of lower elevation, so gravity can force the water out. The grade should always slope away from the home to ensure that the water is directed away from the walls of the home.
  • Cover the pipe with at least 12 inches of washed gravel.
  • Lay filter fabric over the gravel to prevent any soil from clogging the pipe.
  • Back-fill the foundation with top soil back to its original grade height.
Keep Reading

Next Up

How to Build a French Drain

If you're having problems with standing water in your yard or a leaky basement, improper drainage is the culprit. Fix your water drainage issues once and for all by adding a French drain in just a few short steps.

How To: Installing a Fire Pit

A backyard gets more warm and hospitable with a stone firepit.

How to Install Beadboard Wainscoting

Beadboard wainscoting gives a family room a cozy lake-side feel.

How to Install Crown Molding

Install crown molding to add visual interest and value to your home.

How to Install Tile in a Bathroom Shower

Use these step-by-step instructions to take your shower from drab to fab by installing Italian marble tile.

How to Install Wall-to-Wall Carpeting

The experts show how to install wall-to-wall carpeting.

How to Install Snap-Together Laminate Flooring

Installing snap-together flooring allows anyone with moderate DIY skills to create a beautiful new laminate floor.

How to Make and Install an Outdoor Chalkboard

Add a weather-friendly chalkboard to your outdoor space for inspired drawing or score-keeping on family game night.

How to Install a Planked Wood Ceiling

Add architectural detail and rustic, farmhouse charm to a builder basic bedroom with a tongue-and-groove planked wood ceiling. This is also a great way to cover up dated, cottage cheese ceilings or a sloppy drywall job.

Follow Us Everywhere

Join the party! Don't miss HGTV in your favorite social media feeds.