How to Install a French Drain in 10 Easy Steps
Posted by: Erika Green on March 8, 2016
After a heavy rain, does your lawn typically resemble swampy marshland?
If so, you may need a French drain. Like French toast and French fries, French drains don’t actually have anything to do with France. They were popularized here in the U.S. by Henry Flagg French in the 1800s.
If you find your lawn is always soggy due to runoff, or if you notice pools of water after the rain, a French drain is a cheap and easy way to redirect the water and make the space usable again. The best part? It’s something you can easily do on your own on a Saturday afternoon.
Here’s what you’ll need:
- A trencher, mini-excavator or backhoe. Trust us. This isn’t something that you want to try with a couple friends and some shovels. Try renting – both Toro and Kubota offer a number of options* to help you dig the trench:
- Corrugated pipe (with holes or perforations)
- Filter fabric
- A catch basin or drain sump
*Call 888-COMPACT or visit your local Compact Power Equipment Rental to check availability, discuss which piece of machinery best fits your needs and schedule a rental or delivery.
Once you’ve purchased the materials and made your equipment rental reservations, you’re ready to get started.
1. Plan - You need to redirect the water to an area away from your home, and neighboring residences. The catch basin should be installed in the base of the pooling area.
2. Mark out the locations - Depending on the width of your drain, you may need a trencher, backhoe or mini-excavator. To ensure you get the equipment you need, call Compact Power Equipment Rental at least 48 hours before you plan to dig.
3. Call 811 at least 48 hours before you plan to dig. The 811 center immediately alerts the appropriate utility companies of planned digs. Professional locators are then sent to the requested digging site to mark the approximate locations of underground lines using flags, spray paint or both.
4. Determine the slope - The slope of your drain should be 1/8 to 1/4 inch per linear foot. The stake and string method is effective for measuring the difference in elevation. A more detailed method for calculating the slope for your drain can be found here.
5. Break ground (ONLY AFTER 811 notification) - The starting point of your French drain is contingent upon the size of the catch basin or sump or (typically 12" - 20").
6. Excavate the trench - The width of a French drain is 6-12 inches, or about the width of a full-size trencher (6") or backhoe / mini-excavator bucket respectively (12 - 18").
7. Lay the filter fabric - Sometimes referred to as "geotechnical fabric," to prevent soil from getting into the drain and clogging. The fabric should line the bottom of the trench and up the sides.
8. Dump the gravel - Lay 1-2 inches of drain gravel onto the filter fabric before placing the drain.
9. Lay the pipe - Be sure the holes and/or perforations face downward and make sure that all connections are tightly secured.
10. Put on the finishing touches - Place another layer of filter fabric and gravel then top dress the pipe with some of the dirt and fill material created by excavation.
And that’s it. Well, technically, there’s a step 11 but all that involves is running outside during the next rainstorm to see how it all works!