How to Build French Drain: A Step-by-Step Guide

 Are you tired of dealing with water pooling in your yard or basement every time it rains? A French drain might just be the solution you need. It's a type of drainage system that redirects water away from your property, preventing water damage and soil erosion. In this article, we'll guide you through the process of building a French drain, step by step.

French Drain

What Is a French Drain?

A French drain is a trench filled with gravel or rock that contains a perforated pipe. The pipe is wrapped in a geotextile fabric that helps to filter out debris and prevent clogging. The trench is typically sloped to allow water to flow freely towards the pipe, which then carries it away from the property.

What Are the Benefits of a French Drain?

A French drain can have multiple benefits for your property, including:

  • Preventing water damage to your home and basement
  • Preventing soil erosion in your yard
  • Preventing standing water that can attract mosquitoes and other pests
  • Improving the overall drainage of your property

What Are the Disadvantages of a French Drain?

While a French drain can be highly effective, it's important to consider the potential disadvantages before installing one:

  • The installation process can be time-consuming and labor-intensive
  • The cost of materials and installation can be high
  • If not installed properly, a French drain can actually worsen the drainage issues on your property
  • Maintenance may be required to prevent clogging or damage to the pipe

Step-by-Step Guide to Building a French Drain

Step 1: Plan and Measure

Before you begin digging, you'll need to plan out the location and size of your French drain. Consider the slope of your yard and the direction of water flow when choosing the location. Measure the length, width, and depth of your trench to calculate the amount of materials you'll need.

Step 2: Dig the Trench

Using a shovel, dig a trench that's approximately 12 inches wide and 18-24 inches deep. The trench should slope at a rate of 1 inch per every 8 feet to ensure proper drainage. Be sure to check for any underground utilities before digging.

Step 3: Install the Perforated Pipe

Once the trench is dug, lay the perforated pipe in the center of the trench. Make sure the holes in the pipe are facing downwards. The pipe should be sloped along the trench to ensure water flows freely towards the exit point.

Step 4: Cover the Pipe with Gravel or Rock

Fill the trench with gravel or rock, covering the perforated pipe completely. The rock should be about 2-3 inches above the top of the pipe. This will help to filter out debris and prevent clogging.

Step 5: Wrap the Pipe with Geotextile Fabric

Wrap the perforated pipe with geotextile fabric, making sure to overlap the seams to prevent debris from entering the pipe. The fabric should extend to the top of the trench and be tucked in around the edges.

Step 6: Backfill the Trench

Fill the remaining space in the trench with soil, compacting it as you go to ensure stability. The soil should be graded away from the property to allow water to flow freely.


Q: How deep should a French drain be?

A: A French drain should be at least 18-24 inches deep to ensure proper drainage.

Q: Can I install a French drain myself?

A: While it's possible to install a French drain yourself, it can be a time-consuming and labor-intensive process. It's recommended to hire a professional for the best results.

Q: How much does it cost to install a French drain?

A: The cost of a French drain installation can vary depending on the size of the project and the materials used. On average, it can cost anywhere from $20-$30 per linear foot.

Q: How often should a French drain be maintained?

A: It's recommended to have your French drain inspected and cleaned every 1-2 years to prevent clogging and ensure proper functionality.


A French drain can be a highly effective solution for preventing water damage and soil erosion on your property. While it may require some upfront investment and maintenance, the benefits can be well worth it in the long run. By following our step-by-step guide, you can build your own French drain and enjoy a dry, well-drained property.