Non-woven geotextile fabric is the best choice for drainage applications where water flow through (permeability) is the main concern. Non-woven landscape fabric is commonly used in French-drains, drain-fields, and erosion control.
The best material for a french drain is a mixture of clean sand and gravel. This is better than gap graded aggregate. This would be the typical aggregate used in making concrete, but of course without the cement. There is one other possible problem.
French drain depth: About 8 inches to 2 feet deep should be sufficient for many water-diverting projects, though related systems, such as those built around foundations and sub-ground living spaces, as well as the bases of retaining walls, may be deeper.
Line the Drain With Membrane to Minimise Blockage
Once your French drain is installed, maintenance is essential. Don't let it get blocked or you could end up with a moat around your building: great if you're looking to protect it from invaders – and not so great if you're trying to fight damp.
Line the Trench with Filter Fabric
To keep the French drain free of dirt, silt and tree roots, lay water-permeable filter fabric or a weed barrier over the gravel bedding in the trench.
Permits Needed to Install a French Drain
Generally, a small French drain on your property that doesn't change the flow of runoff entering and exiting your yard won't need a permit. Major projects that warrant your French drain to discharge into a municipal sewer or roadside ditch, however, do require one.
A French drain needs to be surrounded by gravel in order to filter out silt and prevent clogging the drain pipe.
Swales: A Natural Solution
They're a great option if you're looking for a more natural, eco-friendly alternative to French drains. A swale is typically lined with grass or vegetation that helps slow down and absorb water.
Clay soil has poor permeability, meaning it doesn't allow water to pass through easily. In such cases, the effectiveness of a French drain may be limited as the water may struggle to drain away from the area efficiently. French drains may not be suitable for areas with high water tables.
Installing a French drain costs $500 to $18,000, with a national average of $9,250. On average, you can expect to pay $10 to $100 per linear foot, or between $500 and $5,000 to have a 50-foot French drain installed.
The drain holes on your pipe should face down if the pipe is half perforated.
Bluestone is highly favored for French drains because of its larger stone size. This size difference allows for better absorption and drainage, ensuring that water is quickly diverted away from your property. The larger stones allow water to flow through, reducing the risk of clogging.
The main difference between the two is that French drains capture and remove groundwater while trench drains quickly remove surface water before it can saturate the ground. Here's a closer look at each type of drain.
Things You Should Know
Add gravel to the bottom of the trench before laying down your drain pipe. Cover the drain pipe in gravel, then fill in the rest of the trench with the displaced dirt you dug up before.
If trench drains channel water that has pooled on the surface of your yard away from your house, French drains manage ground water or water that doesn't necessarily pool on the surface, but rather seeps through the ground immediately.
Just like other types of drains, they are susceptible to clogging over time. Ideally, clean the French drain once every year.
A French drain is an underground system that collects and redirects water through a perforated pipe, preventing it from accumulating in undesired areas. On the other hand, a dry creek bed mimics the look of a natural stream, allowing water to flow along a designated path and away from your property.
One of the biggest French drain mistakes is not lining the trench with drainage fabric. A drain requires a fabric lining to act as a soil separator, in order to prevent any dirt and debris from getting into the drain's gravel lining so water can flow freely.
Clogging and Blockages
Clogging is one of the leading causes of French drain failure, often due to root intrusion or sediment build-up.
Description: #57 Stone is a popular lime rock gravel rock choice for drainage, driveways, and erosion control base material. Because of its cheaper cost, it is often used in french drains and in parking lots.
Connect with local French drain experts to help with your project. Installing a French drain yourself is possible but labor-intensive and time-consuming. Call 811 a week or two before you start your project to get your buried utility lines marked.
You'll likely need a permit since this project may require soil grading to avoid drainage issues. Repairing your floor may be more cost-efficient than replacing it if grading is necessary. No permit may be required to hang drywall on exposed wooden wall studs in your garage.
The ideal distance for a French drain from the house ranges from 5 to 10 feet. This distance provides an adequate buffer to keep water from seeping into and around the foundation, which can be a common cause of damage.