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(100-foot interior perimeter basement drain)
(100-foot shallow exterior drain in the yard)
(100-foot exterior footing perimeter drain)
Cost to install a French drain varies greatly by region (and even by zip code).
Get free estimates from foundation repair contractors in your city.
If you have a soggy yard or water that seeps slowly into your basement, you may want to consider the installation of a French drain to dry things out. A French drain is a very simple setup that helps water drain, redirecting it from where you do not want it to somewhere harmless like a sewer drain or street.
Many types of French drains exist. The size, length, depth, and location of the drain all impact the overall cost of the project. Most homeowners installing a French drain in their basement spend around $4,500 for 100 linear feet of drain. The average cost to install French drains range from $2,800 to $6,500. Costs can be as low as $2,000 for a 100 linear foot drain in an exterior location to as high as $10,000 for a 100 linear foot perimeter drain.
|French drain Installation Prices|
|National average cost||$4,500|
Henry French first described a French drain in a book he wrote about farm drainage in the 1850s. His straightforward solution involved digging a trench through the affected area, lining it with gravel and weed-blocking fabric, laying perforated pipe, and covering it up with more gravel. Water enters the pipe and is carried away to the designated emptying area.
French drains 1 can be shallow or deep and installed in your yard, around the perimeter of your home, or inside your basement. They can be installed alone or paired with a sump pump for very wet areas.
The french drain’s cost per linear foot depends on whether the drain is installed in the interior of your home or the exterior. On average, for exterior installation, you can expect to pay anywhere between $20 to $30 with an average price of $25 per linear foot. A French drain for an internal installation costs from $45 to $60 per linear foot with an average price of $52. Below is a table showing the average cost on some of the most common sizes of drains, less the cost of installation.
|Linear Feet||Average Cost Internal French Drain (Materials Only)||Average Cost External French Drain (Materials Only)|
Most French drains can be categorized as either interior or exterior. From there, they also break down slightly further into more specialized categories that address specific needs. Below is a breakdown of the types of French drains and the average cost for each minus installation.
|Type||Cost per Linear Foot (Materials Only)|
|Exterior||$10 - $100|
|Interior||$50 - $60|
Interior drains need a sump pump to be truly effective. These cost between $550 and $1,100. Larger basements require two. They involve digging a small channel in your concrete to lay the pipe and then covering it with a thin layer of concrete. If interior walls are in the way, they need to be at least temporarily moved for installation.
Interior French drains are very effective at preventing water infiltration into the home. They can easily be installed in existing homes and new builds. The drawbacks are that they can be expensive and invasive, often requiring cutting through concrete and walls. Interior French drain cost for a linear foot runs between $50 and $60.
Exterior drains come in two types - shallow and footing. Shallow drains are most common for draining a soggy yard and are less expensive in general. Footings go around the perimeter of your home and are very deep, often several feet, which causes the costs to increase considerably. They will be visible, so it is common to add decorative pebbles and a curb. The costs to install an exterior French drain runs between $10 and $100 per linear foot.
A shallow French drain is similar to a deeper French drain in the way it operates. The only difference between the two is that a shallow French drain will be closer to the surface, often having only about two inches of gravel. Shallow French drains are ideal for areas without a significant amount of water or are not in areas with an extremely high water table. The average cost for a shallow French drain is $10 to $15 per linear foot.
Interior French drain footing drains are created by leaving a gap between the floor and the wall, which will direct the water down to the drain. It helps route water from seepage through windows, cracks in the walls, or even high condensation levels. It helps keep water out of the basement in the event of a flood. It can be a good option for basements that see regular water accumulation but can become clogged the same as the other types. Footing French drains are more expensive, often running between $80 and $100 per linear foot.
|Exterior French Drain Types||Average Cost per Linear Foot (Materials Only)|
|Shallow||$10 - $15|
|Footing||$80 - $100|
Most french drains utilize a perforated pipe buried in the gravel of the trench to help direct water that is captured to another location where it can be absorbed into the ground. Pipes are most commonly made out of plastic, primarily for their durability and flexibility. French drain pipes come in a variety of diameters. The best width will be determined by how much water or how heavy the rains are in your area. Below is a table of some of the most common diameters and the cost of each per linear foot.
|French Drain Diameter Inches||Average Cost per Linear Foot (Materials Only)|
Most French drains are installed in roughly the same way. A trench is dug in the affected area. The trench’s width and depth are dictated by its location and how much water needs to be drained at a time. Once the trench is dug, it is lined at the bottom with gravel and then covered with a fabric weed blocker. The drain, usually perforated PVC but may be flexible hosing, is laid in the trench and covered with more gravel. If desired, soil may be backfilled on top. French drain pipe costs range from $0.70 and $2.36 per linear foot. The process is similar for basements. However, the finished drain is usually covered with a thin layer of concrete with strategically placed drains.
In some cases, connecting a French drain to a storm drain can be the best option, as it will allow the water to flow out to an appropriate location along with other rainwater. If you have a storm basin on your property or just across your property line, connecting to it can be easy and inexpensive, often costing between $100 to $200 to have the lines coupled together.
The French drain price for the system includes both labor and materials. Labor and material are grouped by installers of French drains, with labor making up the larger share. Labor rates are often charged per linear foot but can be charged with hourly rates between $35 and $75 per hour. For an interior basement drain, the average French drain installation cost per foot is $50, with labor making up about $35 to $40 a linear foot and material making up the rest. For 100 linear feet of installation, this makes labor about $3,500 to $4,000, making the average cost of French drain installation between $4,500 and $5,000.
For homeowners with basements prone to water throughout the year, a combination sump pump and French drain may be the answer. The sump pump is a small device installed in a corner of the basement or lower-lying areas. They are designed to sit in sump pits with the sole purpose of removing water to keep your basement dry. When combined with a French drain, the water flows into the pit and is pumped out by the sump pump into the French drain. Here, it will be carried away from the house. If you install a combination sump pump and French drain, it will cost between $6,000 and $10,000 depending on how many pumps the area requires.
French drains can be installed in several spaces but are most effective when used properly, in the appropriate location, and at the correct depth. When used outdoors, they work best on slopes or downhill areas of your yard, as this assists with drainage. When used primarily to keep water out of the basement, French drains are best located around the perimeter of the foundation. While the average cost of a French drain is around $4,500, the total cost depends on the length and location.
|Location||Cost per Linear Foot (Installed)|
|Yard||$20 - $30|
|Crawl Space||$25 - $35|
|Around Patio||$25 - $40|
|Along Retaining Wall||$25 - $50|
|Under Sidewalk||$30 - $50|
|Under Deck||$35 - $45|
|Driveway||$45 - $55|
|Garage||$50 - $60|
|Around House||$50 - $80|
|Basement||$60 - $70|
On average, the cost of French drain yard installs run between $20 and $30 per linear foot. When installing a French drain in the yard, the most common placement is around the perimeter of your home, though they can be placed in almost any area they are needed. If water in the front of the house is a problem, the drain will often be installed along the front of the foundation with a path that pulls the water around the house. They can also be used in other areas of the property where water buildup tends to be a concern. The cost to install a French drain in the backyard will not be costly as long as the yard is clear of any structural components or utility lines in the way of placement.
On average, a homeowner will pay between $25 and $35 per linear foot for installing a French drain in the crawl space. Adding a French drain to a crawl space can be an important part of waterproofing basements. Since the trench will be dug in the ground, it can be less expensive than interior options. However, the cost increases when you have to work around the crawl space and remove temporary structures. French drains in crawl spaces can be ideal for areas with heavy rains and a high water table.
A French drain around the patio will cost approximately $25 to $40 per linear foot installed. French drains solve the issue of water pooling around the area. Pooled water on the patio becomes problematic because it can cause swampy yards and attract insects. Water exposure around the patio can damage the stone or other material used to make the structure. The drain will start at the patio where the water pools and runs to lower ground.
You can expect to pay anywhere between $25 and $50. If you have built a retaining wall on your property, installing a French drain protects the integrity of the wall. Without one, water moves down the hill and builds up behind the wall, putting pressure on it. Typically, the French drain will be added behind the first course of blocks or stones that back up the base. The pipe used will reside in the same compacted gravel or concrete base footing that supports the wall. The cost to install a French drain along a retaining wall varies depending on the wall materials and the landscape surrounding it.
A French drain under the sidewalk will cost around $30 to $50 per linear foot installed. The extra cost is from the need to dig under the sidewalk to install the French drain. Sidewalks usually measure 4 inches deep, requiring the hole to be dug to that depth. Homeowners choose to run a French drain under a sidewalk area for several reasons. For one, you may be trying to hook up a pop-up emitter set at the curb. This set-up is an alternative to traditional grates and keeps debris out of pipes. Another reason is that a French drain may go under a sidewalk is to extend the downspout through your yard.
You can expect to pay anywhere between $35 and $45 per linear foot to install a French drain under a deck. A French drain under a deck helps protect your home’s foundation, reduces the risk of water in the basement, and preserves the deck’s integrity. The cost of installing a French drain in this location can be higher than installing one in a yard because it may require removing part of the deck.
The cost to install a French drain in the driveway runs between $45 and $55 per linear foot. Though not as expensive as installing a French drain indoors, installing one in a driveway can be costly, especially if it is already there. The removal and relaying of concrete add to the cost. But if you have standing water in your driveway, drainage is important to prevent wear to the concrete or poor driving conditions in areas with freezing temperatures.
Homes with driveways that slope into the garage benefit from a French drain. Installation costs for the driveway run between $50 and $60 per linear foot. The cost to install a French drain in the garage is almost the same as installing one in the interior of the home. The higher cost involves additional labor to tear the concrete up in the garage and replace it once the drain has been installed. Having a French drain installed keeps water from coming through the garage to the home’s foundation.
This option can be expensive, running between $50 and $80 per linear foot. Prices can be affected by structures, utility lines, and landscaping that is likely to be around the outside of your home. If you have a small amount of water in your basement, you can install the French drain around the perimeter of your home to help channel away any groundwater that seeps through your basement walls. If you need a French drain along more than two walls in your basement, this is the better option. A French drain around the foundation may need to be fairly deep, depending on the height of your basement walls.
The cost to install a French drain in the basement runs between $60 and $70 for professional installation. French drains reduce hydrostatic pressure, which is exerted by fluid due to the force of gravity. This pressure causes high water around a home to become forced into basement areas leading to flooding and water damage.
If you have water inside your basement frequently, you can install a French drain inside your basement floor and pair it with a sump pump. In this situation, the channel will be installed inside your concrete floor. The water will be directed to a pum pit, where it can be safely pumped out of the house.
If your French drain is no longer working properly, even after the pipe has been inspected for clogs, it may need to be replaced. Even well-maintained French drains become damaged over time. If pipes become broken or damaged, they can become clogged with silt and debris, making it more difficult for the water to move through. You may find that the French drain’s depth is no longer effective for the water table level and needs to be adjusted.
The costs for French drain replacement vary widely, depending on what damage has occurred and what needs to be redone. If the pipe is damaged and needs to be replaced, you can expect the project to take between three to six hours. This repair costs from $1,000 to $2,500. If the whole area needs to be retrenched and replaced, it can take up to ten hours and cost almost the same as installing a new one. The price ranges from $2,000 to $8,000.
When you install a French drain, you need to have an inspector ensure that it is installed properly, within regulation, and performing correctly. During an inspection, the inspector checks to see that the expelled water does not disturb the adjoining properties or is not at risk for a flooding lawsuit among neighbors. They will check to ensure that the water being expelled is not contaminated and within the lawful limits. Costs for a French drain inspection run between $150 to $250 depending on the length of the French drain and the inspector’s charges for the service. This cost will be in addition to any installation and material costs.
French drains can be dug depths ranging from a few inches to several feet. The depth depends on the drain’s location and how much water is in the area.
If you plan to install a French drain in your basement and have a high water table, you should make sure that the depth is between seven and nine inches. You can go as deep as eight to twelve inches if you have a layer of iron ocher just below the basement floor.
When considering French drain depth for an exterior installation, the minimum effective depth is usually eight to 16 inches below the level of the basement floor. Depths can go lower, especially if you have a low-lying area or experience heavy rains and flooding in the area.
French drains are most useful when you have slow-moving or slow-collecting water. If you have sections of your yard that are always soggy, water that seeps slowly into your basement or crawl space, or water that collects in your driveway, these are signs that you need a drainage system. If this is the case, a French drain may be a good solution for you.
Other times to consider installing a French drain is if you have a retaining wall on a hillside. This could lead to more water by the foundation of your home. A drain could be necessary to pull it away. You also may want to consider a French drain if your property is lower than the properties surrounding you or if your foundation is lower than the land surrounding it. Without a proper drainage system, you may find water is being directed toward your foundation.
French drains can be installed inside or outside of the home, depending on where you have standing water and the severity of the issue. If you have an area in the basement that gets more water than the rest of the basement, you may want to consider installing a French drain along one or two walls. If you find that you need drains along more than two walls to solve the problem, then it is advisable to have a perimeter drain installed around the outside of your home.
Whether you install your French drain inside or outside, the ideal French drain slope is one inch for every eight feet. Your French drain should never have a slope that is less than 1%. A French drain with no slope will be ineffective at pulling water away from the home.
One thing to consider when installing your French drain is where you want the water to drain out. If you live close to a street with a proper storm sewer drainage system, you can direct the water from your French drain out into the street. If you have a heavily grassed area on your property where the drainage is good, you can direct it there. You may tie the drain directly into a nearby sewer line 2, depending on its location.
If you don’t have any of the above options, you may need to consider creating an area for your water. Rain gardens are a popular way to end a French drain. The area is depressed and collects the water from the drain, using it for plants that do well in these conditions like grass and flowering perennials. Rain gardens cost around $1,000 to $3,000, depending on size. Irrigation ditches are an option for giving the water a place to go, rather than allowing it to seep into your yard or home. They may be used alone or with a French drain and cost around $0.50 to $1 a square foot.
A final option to consider is constructing a dry well. Dry wells are large reservoirs to collect water, which will often be designed with holes in them. They are submerged in gavel at the end of the French drain and allow water to drain out slowly. The water is absorbed in the ground without causing a back up. Dry wells can be made from several materials, including plastic, concrete, and loose stone. The cost to install a dry well varies depending on the material being used and cost between $1,500 and $5,000.
As with any type of drainage system, French drains come with both pros and cons. One of the advantages of French drains is that they allow for efficient drainage. A French drain efficiently directs water away from the foundation of your home. You decide where you want the water to be transported and combine it with a sump pump to keep your basement and foundation dry. They are extremely affordable when compared with other methods for waterproofing your basement.
Another benefit is that it improves your lawn. A French drain helps spongy lawns get the drainage they need to stay firm. On top of that, the installation is quick. French drain installation is not difficult and proves to be a quick process depending on its size and complexity.
While there are many advantages to installing a French drain, a few drawbacks can be noted. One of the primary cons of French drains is that some installations may be difficult. While the installation of French drains is relatively quick, in some cases, it can be difficult. If your French drain is installed around gas lines, water lines, or other underground utilities, it can cause safety concerns. An installation may also become problematic if there has to be the removal of certain structures, such as porches and sidewalks. Another drawback is that they become clogged. Even well-designed French drains will eventually become clogged with mud and debris and require annual maintenance to prevent the water from backing up.
Regular French drain maintenance keeps your drain functioning properly and allows it to last for a much longer time. To keep your French drain properly maintained, it should be professionally cleaned out at least once a year. You may need to have it cleaned more often if it seems to be draining slower than normal.
No matter how well your French drain was installed, it will eventually become clogged with dirt, debris, and silt. This can cause it to drain more slowly, making it harder to keep water away from the foundation. When this happens, you need to call in a professional who uses an electric snake to clean the drain from built-up debris. Interior French drain maintenance is extremely important since it can damage your indoor plumbing system. Check the status often to confirm that there are no visible drainage issues.
The process for cleaning the drain can take one to three hours, depending on the severity of the clog and length of the drain. Most professionals charge between $45 and $150 per hour. An average cost range for snaking a French drain is $75 to $500.
Curtain drains and French drains work in similar ways. The biggest difference is that curtain drains are always very shallow, dealing mainly with surface water, while French drains are usually deep enough to handle groundwater or surface water. They are installed in the same manner by digging a long trench to direct water to another location through a piping system. Another difference between the two is the location of their installation. French drains are normally installed around the perimeter of a home to draw the water away from the basement. Curtain drains are typically installed in the front of and slightly around the house to divert the water before getting to the basement. Both French drains and curtain drains cost about the same price. The average per linear foot for French drains is $10 to $100 for exterior, and curtain drains run between $10 and $16 per linear foot.
While both French drains and trench drains are designed to remove water, the type of water they remove and how quickly it is removed make them quite different. French drains are designed to capture groundwater and transport it along a perforated pipe where it will absorb into the ground along the way. Trench drains remove surface water quickly before it begins to absorb into the ground. Trench drains can be significantly more expensive than French drains, averaging anywhere from $30 to $150 per linear foot.
Though sometimes lumped together, French drains and catch basins are completely different systems. They are often used together to create a more robust waterproofing system. While French drains are sub-surface drains, catch basins are surface-level drains. They are connected to either a box or basin where water can be collected quickly and transported to another area. Catch basins are less costly than French drains, running between $2,500 and $5,000 for the complete project.
Sump pumps are designed to pull water out of basements from low lying areas prone to collecting water. They can be less expensive than an interior French drain, costing between $950 and $1,500 on average. Unlike French drains, they rely on electricity, which can become a problem if the power in the home goes out during a storm. Sump pumps are not designed to keep water away from the entire basement and are better suited for targeted areas. Conversely, French drains are designed to draw water away from the entire basement.
Swales are ditches that are concealed with vegetation to collect surface water over an expanse of land. They are designed to have a subtle appearance and blend in with the natural landscape of the area. They are similar to French drains because they’re both designed to drain water. Swales are a general-purpose drain, where French drains are designed to draw water away from a home’s foundation. Swales are typically only found on larger lots.
One of the pros of swales is that they can be very inexpensive, depending on the material used. If using vegetation from seed, the cost will be between $4.50 and $8.50 per linear foot. When using vegetation from sod, the costs go up to $15 to $20 per linear foot. Swales can be a popular option because of their longevity. They often last up to 50 years with minimal maintenance.
One of the biggest drawbacks to swales is that they may not withstand heavy storms. They are not advisable for steep areas and can create a clogging risk for nearby pipes.
Encapsulation systems can be as simplistic as single-layer thin plastic coverings and as high-end as heavy liners with multi-layered vapor barriers. These more advanced systems would also include a dehumidifier, sump pump, and drainage trenches. Installing a crawl space encapsulation after installing a French drain can block out moisture and pests, maintaining the integrity of the space. The average cost to install a crawl space encapsulation is $5,500, including supplies and labor costs. On the low end, you can expect to pay $1,500, and the high range of costs goes as high as $15,000. The price varies based on the size and condition of the space, the contractor’s rates, and the materials used.
If you have a lot of water in your yard, it can cause soil erosion. If this is the case, you may want to install a retaining wall to assist. Retaining walls can be constructed in several ways. A dry stack wall starts at around $4,000 to $6,500, while a poured wall that is 6-feet in height typically costs between $10,000 and $13,000.
Some yards with water issues benefit from installing a dry well, a hole filled with gravel that collects and drains water. These are sometimes called vertical French drains. They have lower costs but are less effective at keeping water away from your home. They start around $100 to $300.
French drains shouldn’t be installed without professional assistance. A contractor will know where to dig the trenches and the correct measurement needed for the pipes. The professional can help you avoid digging in areas that may interfere with utility work.
French drains work because they can collect water from the entire length of pipe and transmit it to the desired area away from the home. French drains solve water issues on the ground level as well as problems with damp basements. The perforations in the pipe will consistently collect water since the pipe won’t be buried underground.
Most homeowners insurance policies will not cover French drains unless added into the policy under a special provision. Neither will most insurance policies cover flood damage unless it is written as a separate policy.
The best way to know if your French drain is operating properly is by checking in your yard or basement. If you detect any presence of water, there is a good chance that your drain is clogged.
Multiple professionals can install a French drain. Waterproofing contractors, basement contractors, drainage contractors, and landscapers all have the skills and equipment to perform the job.
The cost of a French drain varies depending on depth and location, but most people spend around $4,500 on an interior drain.
French drains do not always need an exit. They can be designed to transport water to another location for it to drain if you are in an area with heavy rains, or it can be designed without an outlet and will simply seep in the water as it travels along the perforated pipe.
On average French drains last between 3 and 40 years if well maintained. Some factors may shorten the longevity of a French drain, such as iron ochre in the soil, poor installation, and uncleared clogs.
Curtain drains are usually shallower and installed outdoors, while French drains can be deeper and installed indoors.
This depends on the size of the drain. Install larger and longer drains, if needed, to cover bigger areas.
The water from a French drain can be directed to any area where the water can drain without causing an issue. Common areas include sewers, dry wells, the street, trenches, or rain gardens.
(100-foot interior perimeter basement drain)
(100-foot shallow exterior drain in the yard)
(100-foot exterior footing perimeter drain)
Cost to install a French drain varies greatly by region (and even by zip code).
Get free estimates from foundation repair contractors in your city.