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.
In total, the cost to install a French drain on a residential property should be between $20 and $50 per linear foot, or $2,000 to $5,000 on average for a 100-foot drain. This cost would include the French drain materials, labor, and excavation.
Gravel trenches are a simpler version of the French drain. While they're less efficient, they can be a good option for less severe drainage issues. Water is directed into a trench lined with landscape fabric and filled with gravel.
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.
Generally speaking, a French drain will last approximately 30 to 40 years. However, the above-mentioned factors may shorten its life cycle and it must then be replaced by a team of foundation experts.
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.
If installing the drain involves diverting a stream or affecting a wetland, you likely need a permit to move forward. 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.
French drain installation specialists, landscapers, foundation repair technicians, basement waterproofers, and plumbers can complete this job.
Interior French drains are meant for waterproofing the basement or draining your crawl space. They cost more because contractors must tear out the basement floor (most often made of concrete), install the drain, and then repair it.
A French drain is a trench filled with a perforated pipe and gravel that allows water to drain naturally from your yard. Depending on the size of your yard and the scale of your drainage issue, you can purchase the pipes and equipment to create a French drain yourself.
If you want a drainage system that is less visible or installed around the perimeter of your property, French drains are generally a better choice. However, if you have a high-traffic area where water needs to be quickly and efficiently redirected, channel drains may be the better option.
Landscapers have the expertise to work the French drain installation into your existing landscape design, ensuring it not only functions well but also doesn't interfere with your yard's aesthetics.
Typical labour costs for drainage system installation: Hourly Rate for Tradespeople: £15 - £30 per hour. Total Labour Cost Estimate for Medium-sized Projects: £600 - £1,400.
Aside from what we've listed here, the difference between a French drain and a trench drain is that a French drain is used for water that is underground while a trench drain diverts excess water from a surface.
The type of drain and its length determine total cost. 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 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.
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.
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.
Make sure you excavate the correct pitch (or slope) of your French Drain installation so that water drains into a sump, catch basin, or other drainage feature. There should be a 1-foot drop (sloping downward) for every 100 feet of pipe.
Clogging and Blockages
Clogging is one of the leading causes of French drain failure, often due to root intrusion or sediment build-up.
With stormwater, most likely, your drainage systems would fall under land improvements. Stormwater best management practices such as french drains, downspouts and gutter systems, bioswales, and dry wells could qualify as depreciable assets.
Labor costs: French drain installation is labor intensive, so the local cost of labor has a huge impact on pricing.
Just like other types of drains, they are susceptible to clogging over time. Ideally, clean the French drain once every year.