How much does a French drain cost?
How much does a French drain cost?
$10 – $35 cost per linear foot (exterior in yard)
$40 – $85 cost per linear foot (interior or basement)
$500 – $8,800 average cost to install exterior French drain
$4,000 – $17,000 average cost of interior or basement French drain
French drain cost
A French drain costs $10 to $35 per linear foot or $500 to $8,800 installed on average for a yard or curtain drain. An interior basement French drain costs $4,000 to $17,000 installed or $40 to $85 per foot. Installing a deep, exterior perimeter French drain system or weeping tile costs $30 to $90 per foot.
| Type | Cost per linear foot (LF) | Average total cost |
|---|---|---|
| Surface-level French drain in yard | $10 – $30 | $500 – $5,300 |
| Curtain drain / shallow French drain | $10 – $35 | $1,500 – $8,800 |
| Exterior French drain / weeping tile around house (per side of house) | $30 – $90 | $1,200 – $4,500 |
| Interior perimeter French drain for basement | $40 – $85 | $4,000 – $17,000 |
| Interior French drain for crawl space | $20 – $40 | $2,000 – $8,000 |
Average French drain installation cost per foot
The average French drain installation cost is $10 to $35 per linear foot for a shallow, exterior drain system. Installing an interior basement French drain costs $40 to $85 per linear foot on average. Length, depth, materials, and accessibility affect the cost.
| Length | Exterior / yard ($10 – $35 per LF) | Interior / basement ($40 – $85 per LF) |
|---|---|---|
| 25' | $250 – $900 | $1,000 – $2,100 |
| 50' | $500 – $1,800 | $2,000 – $4,300 |
| 100' | $1,000 – $3,500 | $4,000 – $8,500 |
| 125' | $1,300 – $4,400 | $5,000 – $10,600 |
| 150' | $1,500 – $5,300 | $6,000 – $12,800 |
| 175' | $1,800 – $6,100 | $7,000 – $14,900 |
| 200' | $2,000 – $7,000 | $8,000 – $17,000 |
| 250' | $2,500 – $8,800 | $10,000 – $21,300 |
Installing a shallow French drain takes up to a day in an easily accessible yard that does not require resloping.
Installing a deep, exterior perimeter French drain for an existing home may take several days due to the extensive excavation needed.
Interior French drain system costs
An interior French drain costs $2,000 to $8,000 for labor and materials when installed in a crawl space. The interior French drain installation cost for a basement is $4,000 to $17,000, costlier as it requires breaking the concrete floor perimeter. Interior drainage systems typically include a sump pump.
| Type | Average cost (per linear foot) | Average installed cost* |
|---|---|---|
| Crawl space | $20 – $40 | $2,000 – $8,000 |
| Basement perimeter | $40 – $85 | $4,000 – $17,000 |
Other names for interior French drain systems include weeping tile, drain tile, perimeter drain, and footer drain system.
An interior perimeter basement drain system costs less when installed during new construction.
Basement French drain cost
A basement French drain costs $40 to $85 per linear foot installed and involves excavating the trench, filling with gravel and a perforated pipe, and connecting to one or more sump pumps. Retrofitting a basement French drain requires digging up the basement floor perimeter to reach the foundation footings.
| Basement perimeter | Sump pumps | Average installed cost |
|---|---|---|
| 100' | 1 | $4,000 – $8,500 |
| 125' | 2 | $5,000 – $10,600 |
| 150' | 2 | $6,000 – $12,800 |
| 175' | 2 | $7,000 – $14,900 |
| 200' | 2 | $8,000 – $17,000 |
Basement waterproofing costs $4,500 to $15,000 on average with installation and often includes sump pump installation. Installing an interior French drain system at the same time may reduce the French drain cost.
Rebuilding a foundation costs $20,000 to $40,000 and may be necessary if major water damage goes unresolved.
Cost to install sump pump and French drain
The average cost to install a sump pump and French drain is $50 to $100 per linear foot. The cost to add a sump pump to a French drain is $600 to $2,500. Interior perimeter French drain system typically require a sump pump to move water away from the foundation.
Exterior French drain systems benefit from a sump pump when gravity alone does not move water away from the home successfully.
Crawl space French drain cost
A crawl space French drain costs $2,000 to $8,000 installed. The drain runs along the perimeter, sloping toward a sump pump to move water away from the foundation. A crawl space's short height adds challenge to installation but digging through the dirt floor requires less labor than concrete basement excavation.
Wet crawl space repair costs $1,500 to $5,000. Crawl space cleaning or mold removal costs $1,500 to $4,000.
Crawl space encapsulation costs $1,500 to $4,000 for basic encapsulation or $5,000 to $15,000 when including a French drain system, new insulation, and a robust dehumidifier.
Cost to install French drain in yard
Installing a French drain in a yard costs $10 to $35 per linear foot, depending on the length, depth, and site conditions. French drains often install at or near a home's downspouts and follow a downward slope to move water away from the home and prevent water pooling.
| Length | Average installed cost |
|---|---|
| 25' | $250 – $900 |
| 50' | $500 – $1,800 |
| 100' | $1,000 – $3,500 |
| 125' | $1,300 – $4,400 |
| 150' | $1,500 – $5,300 |
| 175' | $1,800 – $6,100 |
| 200' | $2,000 – $7,000 |
Trench excavation costs $500 to $1,200. French drain installation estimates typically include excavation.
Yard regrading costs $500 to $5,000 and may be required if the yard does not slope downward away from the house.
Exterior French drains move water to the street, another drainage location away from the home, or they connect to a dry well, sump pump basin, or storm drain.
Dry well or vertical French drain cost
A dry well or vertical French drain costs $50 to $3,000+ installed, depending on the soil, materials, and depth. A dry well is a deep, covered hole that collects and drains water into the ground, often fed by one or more French drains moving water away from the home.
| Type | Average installed cost |
|---|---|
| Gravel / Loose Stone | $50 – $250 |
| Prefabricated Plastic Tank | $200 – $700 |
| Concrete Tank | $500 – $3,000+ |
A dry well or vertical French drain works well for areas with no nearby drainage outlet.
The amount of water draining determines the dry well depth needed.
A perc test costs $600 to $2,000 to assess the soil's suitability for a dry well.
Exterior perimeter French drain cost
An exterior French drain costs $30 to $90 per linear foot for a deep, perimeter weeping tile drain system installed at the foundation footings. Shallow, exterior French drains cost $10 to $35 per linear foot, with surface-level drains installed less than 2' deep and curtain drains installed 2'+ deep.
| Type | Average cost per foot | Average installed cost* |
|---|---|---|
| Surface-level perimeter French drain | $10 – $30 | $1,500 – $7,500 |
| Curtain perimeter drain | $10 – $35 | $1,500 – $8,800 |
| French perimeter / weeping drain tile / deep drain | $30 – $90 | $4,500 – $22,500 |
*Average cost for 150' to 250' feet.
A surface-level French drain moves mostly surface water. The gravel trench is visible and even with the surrounding landscape.
A curtain drain moves mostly groundwater. The trench is often covered with sod and blends into the landscape.
A deep French perimeter drain moves underground water away before it can penetrate the basement.
French curtain drain cost around house
A curtain drain costs $10 to $35 per linear foot or $1,500 to $8,800. A curtain drain is 2'+ deep and installed around a house's exterior or yard to move ground water away from the home. Curtain drains are like surface-level French drains but slightly deeper and soil covered.
Cost factors to install a French drain
Factors affecting drainage system installation cost include:
| Factor | Average cost for 100 to 200 feet |
|---|---|
| Pipe | $100 – $1,000+ |
| Drainage gravel | $100 – $600 |
| Permeable landscape fabric | $40 – $360 |
| Trenching | $500 – $2,400 |
| Installation labor | $700 – $8,000 |
| Sump pump | $500 – $1,800* |
| Dry well | $50 – $3,000+* |
*Including installation.
Type – Drain type plays a significant role in determining labor costs.
A deep, exterior weeping tile drain requires excavation down to the foundation footings, with labor and equipment costing much more than a shallow drain.
Installing an interior drain in dirt floor crawl space requires less labor and equipment than a concrete floor basement.
Location & accessibility – Installing in difficult to reach areas or with outdoor obstructions takes more time and may require more materials to replace elements that required digging up or removal.
Size, depth, & length – Longer, deeper drainage systems take more time to excavate and more materials to install.
Basement size – A large basement may need more than one drain.
Renovations – Installing an interior basement drainage system during a full basement renovation may reduce the drain installation cost.
Geographical location – Labor rates are higher in large cities than in small, rural towns.
Materials –
Pipe – Drainage pipe costs $1 to $5+ per linear foot.
Fabric – Drainage fabric costs $0.40 to $1.80+ per foot. Heavy, professional grade fabric costs more but has a high flow rate and is more durable, ensuring a long lifespan.
Drainage rock – ½" to 1 ½" washed gravel rock costs $1 to $3 per foot on average. An ideal French drain has 2 to 3 inches of gravel under the pipe and about 3 to 4 inches covering the pipe.
Labor – Labor accounts for the majority of French drain installation cost. Total labor cost depends on the project size, the professional type hired, and local rates.
Digging a trench costs $5 to $12 per linear foot or $500 to $1,200 for a 100' trench.
Landscapers charge $50 to $100 per hour for trenching and drainage system services.
Plumbing companies cost $40 to $150 per hour.
Renting a trencher costs $100 to $200 per day for DIY installation.
Drainage – A property with no natural downward slope may require additional landscaping work to create an effective French drain.
Water discharge – Installing a sump pump costs $500 to $1,800, while dry well installation costs $50 to $3,000+. French drains may also discharge into a storm drain which often requires additional permit fees.
Drain inspection – Some areas require an inspector's approval signature before covering the French drain with gravel, soil, or concrete.
Permits – French drain permits cost $100 to $375, or more if connecting to a public storm drain. Most areas require a permit. Call 8-1-1 to have utility lines marked before the work begins to prevent issues.
Soil erosion – Installing a retaining wall costs $40 to $300 per linear foot and helps prevent soil erosion. Houses in the path of storm runoff have a higher soil erosion risk.
Landscape restoration – Some French drain installations require damaging the lawn. Repairing the landscaping may require additional labor and materials.
Water damage – Water damage may result in foundation problems or mold issues.
Foundation repair costs $250 to $800 per crack for minor repairs or up to $20,000 for major repairs involving hydraulic piers.
Mold remediation costs $1,500 to $6,000.
Material disposal – Concrete or dirt disposal adds to the installation cost. Consider reusing the trenched soil in other areas of the yard to reduce disposal fees.
French drain cleaning cost
French drain cleaning costs $80 to $500+, depending on the clog severity. French drains are low maintenance, but clogging may occur from incorrect installation, root intrusion, or debris buildup over time. Contractors clear the line with an electric sewer snake and flush out remaining debris with water.
French drain pipe costs
French drain pipe costs $1 to $5+ per foot. Corrugated pipe is the cheapest and is flexible and easy to install. PVC costs more and often needs more connections but is more durable and long lasting. Prefabricated EZ-drain pipe has a higher price but installs without gravel, reducing labor.
Hydroblox planks cost $10 to $20 per foot and are a French drain pipe alternative made of 100% recycled plastics. Water moves through small spaces in the planks and from plank to plank by water pressure and gravity. Installers bury the planks in a trench and backfill with good soil.
| Pipe type | Average cost per foot |
|---|---|
| Corrugated | $1.00 – $3.00 |
| PVC | $1.20 – $5.00 |
| EZ-drain pipe / prefabricated | $7.00 – $10.00 |
| Hydroblox planks | $10.00 – $20.00 |
Corrugated pipe works well on curved slopes as it bends easily.
PVC pipe is the best choice for deep, footing drain systems since it is more durable and handles a plumber's snake without pipe damage risk.
Pipe sleeves or pipe socks cost $0.25 to $0.70 per foot and keep debris out of the pipe, but they leave the trench gravel unprotected. Lining the trench with geotextile fabric instead is a better choice to prevent clogging.
French drain FAQs
What is a French drain?
A French drain is a slightly sloped trench containing a perforated pipe surrounded by gravel, designed to move water away from the home. Water sinks through the gravel, into the pipe holes, and travels down the channel by gravity. A French drain's capacity depends on the trench and pipe width.
A 3"-to 4"-wide pipe is suitable for most residential applications.
Covering a French drain with dirt slows and may stop the drainage process, depending on the soil type.
Wrapping the gravel and pipe with non-woven geotextile fabric and covering with more gravel or turf grass with 1 to 2 inches of attached roots works best in most regions.
When do I need a French drain?
Signs you may need a French drain include:
A soggy yard.
Standing or pooling water in the yard or driveway.
Increased interior humidity.
Water in the basement or crawl space.
Mold in the basement.
Is a French drain worth it?
A French drain is worth it if it is installed correctly and protects your home and property from costly water damage. Consider a French drain if you are experiencing standing or pooling water in the yard or driveway or water in the basement or crawl space.
A French drain in a region where rains are frequent but light may cause damage due to increased hydrostatic pressure against the foundation.
How deep should a French drain be?
A French drain should be 12" to 24" inches deep, at least 12" wide, and 2 to 5 feet away from the home's foundation in most cases. The drain must run away from the property on a slope of at least 1%, or 1' lower for every 100' of drain.
Do French drains need an outlet and inlet?
Not all French drains need an outlet and inlet. The water amount, drain length and depth, and soil permeability affect whether an inlet and outlet are necessary.
French drains receiving a lot of water all at once typically have at least one inlet.
French drains dispersing water fast enough into the ground as it moves along the perforated pipe require no discharge outlet.
French drains needing an outlet may discharge "to daylight" at another location away from the home, to a dry well, a sump pump, or to a nearby storm drain.
How long do French drains last?
Most French drains last 30 to 40+ years when installed correctly. French drain systems with a sump pump typically need service within 10 years.
French drains in sandy soil or high vegetation areas often have shorter lifespans.
Experts recommend cleaning a French drain system at least once per year. Areas with clog-causing iron ochre in the soil require more frequent cleaning.
Who installs French drains?
Landscaping contractors typically install outdoor French drains.
Foundation repair contractors, drainage services, and basement waterproofing companies may install interior and exterior perimeter French drain systems.
How long does it take to install a French drainage system?
Installing a French drainage system takes 4 hours to 3+ days, depending on the type, length, and materials. Shallow exterior French drains and interior perimeter drains install quicker than deep, exterior drain tile systems requiring extensive excavation and landscaping disruption.
Getting estimates from French drain installers
Before hiring drainage contractors, be sure to:
Ask for recommendations from family, friends, co-workers, or neighbors.
Check their reviews on HomeGuide and Google.
Confirm the business is licensed, bonded, and insured.
Hire a company that has been established for at least 5 years.
Ask for references with contact information.
Get at least 3 to 4 detailed estimates in writing to compare.
Avoid going with the lowest quote as quality may suffer.
Never pay in full before the project starts. Use a payment plan or schedule payments for work completed.
Questions to ask
Are you licensed, bonded, and insured?
Can you supply local references?
Do you have a portfolio of past drainage system installation work?
What type of drainage system is best for my situation?
Does the drainage system need an inlet and outlet?
Do you run specials?
What is included in your warranty?
What kind and size of gravel do you use?
What type of fabric and tubing do you recommend?
How long will the installation take?
Who will be supervising the installation?
How long should the drain system last?
What maintenance is needed after installation?
Do you offer a maintenance plan?
What is and is not included in the estimate?
What additional costs should I expect?