Don’t let your remodeling budget go over-board by hidden surprises – understand what the average installed costs for a French drain is near you by using our easy to use calculator.
As an experienced licensed home improvement contractor, I know first hand what it should cost for various levels — from Basic, Better, and of course the best.
This French drain installation cost estimator will provide you with up to date pricing for your area. Simply enter your zip code and the Linear footage, next click update and you will see a breakdown on what it should cost to have French drain installed onto your property near you.
|French Drain Cost Calculator
||Zip Code||Linear feet|
|Material Prices||$900.00 – $1200.00||$1400.00 – $1800.00||$1600.00 – $2400.00|
|Installation Cost||$800.00 – $1500.00||$2800.00 – $3500.00||$3800.00 – $4500.00|
|Total||$1700.00 – $2700.00||$4200.00 – $5300.00||$5400.00 – $6900.00|
|Average Cost per Linear foot||$22.00||$47.50||$61.50|
How Much Does a French Drain Installation Cost?
Moisture in your basement is more than a nuisance — it can ruin your foundation. How can you keep it dry? There are dozens of options for waterproofing, but among the simplest and most cost-effective is a French drain. Prices range from as little as $1850 installed to as high as $11,500 depending on the cost of materials and labor — the national average is $5700.
What is a French drain?
Also known as weeping tile, a French drain is a system of perforated pipe laid in a trench around the perimeter of your home or under your basement floor. Named for American agriculturist Henry French, it’s sole purpose is to direct water away from your basement to a location where it can be safely absorbed.
Why choose a French Drain?
Basements are moist for many reasons — French drains address only some of them. Water seeping through unsealed window wells or cracks in your foundation will require additional measures to fix.
But if the problem is poor drainage around your property, a French drain can help whisk excess water away before it takes the path of least resistance into your home.
Signs that you need a French drain include:
- Soggy or muddy soil near your foundation
- Water in your basement every time it rains
- Standing puddles of water on your lawn or driveway
- Basement humidity
- Mold on foundation walls
Types of French Drains
|Type||Cost Per Linear Foot|
|Exterior French Drain||$30-$38|
|Interior French Drain||$50-$70|
French drains come in two types — interior and exterior.
Cost to Install an Interior French Drain
Interior French drains are located beneath the edges of a basement floor where they direct seepage to a sump pit. They’re inexpensive when added to new construction, but installing one after a home is built is costly — especially if the foundation is concrete.
On average, prices range from $50–$70 per linear foot — almost 80% of that is labor. Expect to pay $5400 – $6900 for 100 linear feet of pipe installed — adding a sump pump could drive the total cost to $9,500 or more.
Cost to Install an Exterior French Drain
Exterior French drains can be remarkably budget-friendly, depending on your landscaping and how deep they need to be. Installed around your foundation, shallow versions designed to capture surface water during heavy rain require a 1-foot by 1-foot trench — costs for material and labor range from $20 to $30 per linear foot or an average of $4200 – $5300 per 100 feet of drain installed.
For homes in wet areas where the soil is persistently saturated, drains are installed closer to the base of the foundation, and the deeper they are, the more they cost.
Installation Cost Factors
Here’s a look at how each part of your project contributes to its cost.
Both interior and exterior French drains sit in a bed of crushed gravel that filters out large debris so it won’t clog perforations in the pipe. At roughly $1.40 per square foot installed, 0.50-0.75 square feet of 1.5–2-inch gravel per linear foot of shallow drain will cost between $70 and $100. Gravel for deep outdoor drains could add up to $700 to the cost of your project.
Exterior drains also require a layer of landscaping fabric at the base of the trench to prevent weeds at an average of $65 for a 100-foot drain — or you can replace the standard perforated pipe with a flexible type that comes wrapped in water-permeable fabric for about the same price.
In basements used solely for storage, interior drains are usually covered by gravel alone, but grates are recommended for both safety and aesthetics when the area is used as living space. At $6.70–$10 per linear foot, grating costs $67–$100 for a 100-foot drain.
Exterior French drains are most effective when they slope away from your property — landscapers recommend a drop of one inch for every 10 feet. That means that as the trench is built, installers must dig deeper as they go, adding to the cost of labor. The slope may be slightly less on interior drains because water doesn’t have to flow as far.
It’s not unusual for contractors to dig shallow outdoor drains by hand, but installing pipes at the base of your foundation requires heavy equipment. In addition to rental fees, you’ll pay a little more for labor because it requires a skilled operator.
The water a French drain catches has to go somewhere. If your home is close to the road, it can be diverted to the street or a culvert, but if you have a large property, you may need to choose a closer space.
A dedicated drainage area can be as simple as natural depression in your landscaping or a dry well, but you can get the most out of your drain by collecting water in a rain barrel or an irrigation ditch where it can be used for other purposes.
Water from indoor drains is pumped outdoors or tied into a sewer.
Digging in tight spaces is tough, so you’ll pay more for installation in challenging areas such as short crawlspaces or yards that closely abut a neighbor’s.
If your drainage site is far from your house, you’ll also need to figure in additional materials and labor — $25–$35 per linear foot, all-inclusive, is a good rule of thumb.
Sump pumps sit at the lowest point of your basement so that if water gets in, it rolls toward the sump pit where it collects. An interior French drain does one better by keeping your floor drier — it catches water before it travels away from walls, but it still requires a sump pump to remove.
The cost of a new sump pump plus the labor to install it ranges from $650 to $1800 — most homeowners spend about $1200. It’s a necessary part of an interior French drain system.
Permits and Fees
Installing a French drain may require an inspection and permit to ensure your home’s drainage fix doesn’t become your neighbor’s problem. Permits range in price from $25 to $100, and homeowners should clarify if they or the contractor are responsible for obtaining permits before work begins. Before digging on your property, asking local utility companies to mark underground lines is a must for safety.
Pieces of concrete flooring and organic material dug out of trenches require disposal, adding to the cost of labor. The volume of dirt can be significant, so it pays to plan ahead and know what you’ll do with it in advance.
DIY vs. Professional Installation of a French Drain
Installing a shallow exterior French drain is a job the average homeowner can do, but rental fees on the heavy equipment for digging deep trenches or breaking up concrete flooring — as well as safety factors —may offset the savings. Complex installations are best left to the experts.
What is a vertical French drain?
A vertical French drain is a deep hole filled with gravel that helps collect rainwater. Also known as dry wells, several can be dug around a property for maximum drainage, but they’re typically not as effective as true French drains.
How long will a French drain last?
A professionally installed and properly maintained French drain can last for decades.
Is using rigid or flexible pipe better?
Flexible pipe covered with a water-permeable textile is easier to install, and it costs less by eliminating the need for landscape fabric — but it deteriorates faster. Rigid pipe lasts longer, and it can be cleared with a snake without fear of damage if it ever becomes clogged. Most experts recommend rigid PVC pipe for deep installations.
How can I save money on French drain installation?
You can save by:
- Getting at least four competing bids.
- Buying and delivering your own materials.
- Doing some or all of the work yourself if you’re handy around the house.
- Using excavated dirt for fill in other areas of your property.
There is no one-size-fits- all approach to a wet basement, but whether it stands alone or is just one part of the solution, a French drain is an essential component in a comprehensive drainage plan.
- Home Depot How to install a French drain
- Lowes Plumbing products and supplies
- Principals of water drainage: NDS
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