How Much Does It Cost to Waterproof a Basement?

Average range: $3,000 - $7,000
Average Cost
(Interior French drain and sump pump in a 1,000 sq.ft. basement)

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Reviewed by Nieves Caballero. Written by

Your basement is the foundation of your entire home, which could be in trouble if your basement becomes compromised. Water can infiltrate the basement in many ways, from hydrostatic pressure to overflowing gutters, and cause your home significant damage. Even a small amount of water can lead to issues like sticking doors, mold, mildew, and cracks in your concrete, so address basement waterproofing as soon as possible. Every basement is different, so your needs may vary. Many things can waterproof a basement, from mild damp proofing to full interior and exterior waterproofing. This means there is a wide range of associated costs.

The national average cost range to waterproof a basement is $3,000 to $7,000. Most people pay around $5,500 for an interior French drain and a sump pump in a 1,000 sq.ft. basement. This project’s low cost is around $1,000 for applying sealant to the interior walls and fixing one crack with epoxy. The high cost is around $10,000 for an exterior perimeter French drain, sump pump, and exterior sealant on the walls with epoxy-fixed cracks.

Basement Sealing Price

Basement Waterproofing Cost
National average cost$5,500
Average range$3,000-$7,000

Basement Waterproofing Cost by Project Range

Applying a sealant to the interior walls and fixing cracks with epoxy
Average Cost
Interior French drain and sump pump in a 1,000 sq.ft. basement
Exterior French drain, sump pump, and exterior sealant with cracks fixed with epoxy

Basement Waterproofing Cost per Linear Foot

There are two ways to price your basement waterproofing because there are two basic methods - perimeter work and covering the walls and floors. The perimeter work is charged by the linear foot, with a cost range of between $50 and $100 a linear foot. This waterproofing involves laying a weeping tile or a French drain 1 around the basement’s perimeter, on the interior or exterior. It may be combined with other methods, but those are given a separate cost, such as a sump pump, or square footage cost, such as sealing the walls and floors.

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Basement Waterproofing Cost per Square Foot

If you are having a lot of work done on your basement, you can calculate the project’s total cost in square feet. The average cost of waterproofing a basement is between $3 and $10 a square foot. This range is due to the enormous differences in waterproofing types and their varying costs. 

Cost to Waterproof a 500, 800, 1000, 1200, and 1500 Sq Ff Basement

Cost to Waterproof a 500, 800, 1000, 1200, and 1500 Sq Ft Basement

Basement SizeWaterproofing Cost
500 sq.ft.$1,500 - $5,000
800 sq.ft.$2,400 - $8,000
1,000 sq.ft.$3,000 - $10,000
1,200 sq.ft.$3,600 - $12,000
1,500 sq.ft.$4,500 - $15,000

Average Cost to Waterproof a Basement by Location

While you are most likely to see the water seeping into your basement from the inside, you can waterproof the inside and outside. The most effective waterproofing combines aspects of both, and waterproofing your exterior can be your first line of defense. However, any waterproofing can protect your home from water damage.

Interior or Exterior Basement Waterproofing Cost

Interior or Exterior Basement Waterproofing Cost

LocationWaterproofing Cost
Interior$500 - $10,000
Exterior$3,000 - $15,000

Interior Basement Waterproofing Cost

The average costs related to waterproofing your basement interior range from $500 to $10,000, depending on the job. While waterproofing is most effective on the exterior, it is easier to waterproof the exterior on a home under construction. So, interior waterproofing is most common for existing homes. Several methods of waterproofing can be used indoors, from sealing your walls and floor to installing a French drain and sump pump 2. Some methods are more expensive, but they may also be more effective.

Exterior Basement Waterproofing Cost

The average cost to waterproof your basement’s exterior is between $3,000 and $15,000. Exterior waterproofing is most commonly done when the home is built. This is because once the foundation has been backfilled, it is difficult, expensive, and sometimes dangerous to access. Some excavation is required to waterproof the exterior. This may be a little or a lot, and multiple types of waterproofing are often undertaken at once to maximize the efforts. The cost varies depending on if you are waterproofing an existing home or one under construction.

Interior Basement Waterproofing Cost by Type of Project

Many methods and material types can waterproof the basement’s interior. You may wish to combine several techniques to make your waterproofing more successful. Ultimately, what you choose to do should be determined by the water’s source, entry cause, and severity.

Interior Basement Waterproofing Cost by Type of Project: Waterproofing Paint, Wealing, Interior French Drain, Epoxy Injection, and Sump Pump

Interior Basement Waterproofing Cost by Type of Project: Waterproofing Paint, Wealing, Interior French Drain, Epoxy Injection, and Sump Pump

ProjectAverage Costs
Waterproofing Paint$1 - $2/sq.ft.
Sealing$3 - $7/sq.ft.
Interior French Drain$50 - $60/linear foot
Epoxy Injection$350 - $500/crack
Sump Pump$700 - $1,600/unit

Basement Waterproofing Paint Cost

Waterproof paint costs between $1 and $2 a square foot installed. This is the lowest-cost method of protecting your basement. The paint is put directly onto the concrete. The concrete must be clean, bare, and not have been painted in the past. It cannot have any efflorescence on it - the white mineral deposits on concrete that have become damp. Waterproof paint is not as effective as sealing, but it can be a good first step to helping your basement stay dry.

Cost to Seal a Basement

The cost to seal your basement ranges from $3 to $7 a square foot. Sealants are rolled, sprayed, or painted on similarly to paint. They do not affect the concrete’s appearance but prevent water from seeping through more effectively than waterproof paint. Sealants are good if you plan to finish your basement and want some protection beneath your finished walls. They are also a good choice for basement floors you want to leave bare. They come in several types, and you can combine them.

Cost per Sq Ft to Apply an Acrylic, Silicate, or Epoxy Sealant

Cost per Sq Ft to Apply an Acrylic, Silicate, or Epoxy Sealant

Type of SealantCosts per Square Foot (Installed)
Acrylic$3 - $4
Silicate$4 - $6
Epoxy$5 - $7

Acrylic Sealants

Acrylic sealants cost between $3 and $4 a square foot installed. Acrylic is a permanent solution to concrete water seepage. This is a good option if you have weeping concrete because the acrylic fills all pores and prevents moisture from coming through. It is very durable and flexible so that it moves with the concrete. This is a topical sealant, so it remains on the concrete’s surface. You cannot apply anything over it, so using acrylic means that the concrete maintains its current appearance. It can also give off strong VOCs while curing.

Silicate Sealants

Silicate sealants range from $4 to $6 a square foot installed. Silicates are flexible sealants that also offer permanent sealing. This is an impregnating sealer rather than topical. This means it enters the material instead of sitting on the concrete’s surface. You cannot see it once it is applied. You can also go over it with another material. It is very common to use a silicate sealer first and epoxy later to give the concrete a different appearance.

Epoxy Sealants

Epoxy 3 sealants average $5 to $7 a square foot installed. Epoxy is also a surface sealant. It is tough and flexible but difficult and time-consuming to install. Epoxy changes the concrete’s appearance. This can be used to give your basement walls or floors a different appearance while preventing water from penetrating. If you have moisture problems, you can use a silicate sealant and epoxy on top. This permanently and effectively ends moisture penetration through the walls or floor.

Interior French Drain Cost

The cost of an interior French drain is between $50 and $60 a linear foot. A French drain is sometimes called a weeping tile or drain tile installation. It can be installed around your basement’s inside perimeter to collect and direct water to a sump pump or other site away from your home. A small trench is dug around the inside perimeter to install the French drain indoors. This means removing the concrete. Once the surrounding drain and gravel are installed, new concrete is applied to restore your basement floor.

Epoxy Injection Crack Repair Cost

Epoxy injections for crack repair cost $350 to $500 per crack. Epoxy injects are applied to the cracks through a port. The epoxy is flexible and does not crack when the basement moves or settles. It is waterproof and durable, so it can last for years without problems. The epoxy cures within about 5 hours after it is applied. This can effectively stop water from entering through cracks in your basement walls or floor.

Sump Pump Installation Cost

The cost of a sump pump installation is between $700 and $1,600. Sump pumps get the water out of your basement before it collects. The sump pump can be placed in the lowest part of your basement or yard, or it can have a French drain or another drainage system. The water collects in the sump’s basin. When it reaches a certain level, it activates and pumps the water up and out of your home. It is most effective when paired with a drainage system like a French drain.

Cost of a Pedestal or a Submersible Sump Pump

Cost of a Pedestal or a Submersible Sump Pump

Type of Sump PumpAverage Costs (Materials Only)
Pedestal$80 - $180
Submersible$135 - $300

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Exterior Basement Waterproofing Cost by Type of Project

Stopping water from infiltrating the outside is much more effective than attempting to waterproof the interior. While most of these techniques are easier and less expensive on new construction, most still work on existing homes. Some must be done together - excavation must take place before sealing of exterior walls or an exterior French drain can be installed.

Exterior Basement Waterproofing Cost by Type of Project: Gutters, Exterior Walls Sealing, Exterior French Drain, Exterior Excavation, and Window Wells

Exterior Basement Waterproofing Cost by Type of Project: Gutters, Exterior Walls Sealing, Exterior French Drain, Exterior Excavation, and Window Wells

ProjectAverage Costs
Gutters$3 - $30/linear foot
Exterior Walls Sealing$3 - $7/sq.ft.
Exterior French Drain$80 - $100/linear foot
Exterior Excavation$100 - $200/linear foot
Window Wells$500 - $1,500/well


The cost of installing gutters on your home is between $3 and $30 a linear foot. Gutters are an integral part of keeping your basement and foundation dry. They direct water away from your home and foundation. When they become clogged or fail, water can pool around your basement. When this happens, it is only a matter of time before it comes inside. Functioning gutters are often considered a major part of basement waterproofing.

Waterproofing Exterior Basement Walls Cost

Waterproofing your exterior basement walls can be a good first step to controlling moisture. Keep in mind the walls must be completely exposed. In some basements, the walls are partially exposed already. In others, they may need to be completely dug up. All of these methods must be backfilled after being applied. This means that excavated dirt must be filled back in to fully protect the basement.

Cost per Sq Ft to Apply Bentonite Sheets, Liquid Membrane, Sheet Membrane, or Cementitious (Parging) Coating for Exterior Waterproofing

Cost per Sq Ft to Apply Bentonite Sheets, Liquid Membrane, Sheet Membrane, or Cementitious (Parging) Coating for Exterior Waterproofing

Type of Exterior SealantAverage Costs per Sq.Ft.
Bentonite Sheets$3 - $4
Liquid Membrane$3 - $6
Sheet Membrane$3 - $7
Cementitious (Parging)$4 - $6

Bentonite Waterproofing Cost

Waterproofing with bentonite sheets averages $3 to $4 a square foot. Bentonite is a clay-based material that expands and fills cracks on your basement’s exterior. The sodium bentonite in the clay bonds with water molecules on contact. This bond causes the clay to expand, so the walls are still protected even if cracks form later. This is a good choice if you have wet soil in your area. It is considered a temporary solution because it does not last forever.

Liquid Membrane Waterproofing

Liquid membrane waterproofing costs between $3 and $6 a square foot. This is a continuous liquid waterproofing agent applied to your foundation’s exterior. It is very long-lasting and durable. It can keep water out for years without additional treatments. However, it requires multiple coats to be effective. Each manufacturer may have its own application method, so find a contractor certified in the material you choose.

Sheet Membrane Waterproofing

Sheet membrane waterproofing ranges from $3 to $7 a square foot. Sheet membranes stretch around your foundation. They have seams between sheets, which can be a potential source of failure. The walls need extensive preparation for this method if the concrete is not fresh during new construction. Therefore, this method can be time-consuming. Only one layer is needed, which makes the wrapping fast and easy.

Parging Basement Walls Costs

Parging or applying a cementitious coating to your basement walls costs between $4 and $6 a square foot. Parging is done for cosmetic reasons on the home’s exterior. It is applied to the visible basement walls and thickens the wall’s exterior. This may provide some additional moisture protection. Parging should be combined with another method of waterproofing for the best results. Relying on it alone may not have the desired effect.

Exterior French Drain Cost

Exterior French drains, weeping tiles, or exterior drain tile systems cost between $80 and $100 a linear foot installed. This system collects water around the perimeter of your basement foundation and directs it away. It can take it to another area in your yard or a sump pump. The sump pump expels the water away from the foundation. There are many types of exterior French drains or drain tile systems. The type used in basement waterproofing is a footing drain.

Exterior Excavation Waterproofing Cost

The cost of exterior excavation for waterproofing averages $100 to $200 a linear foot. Excavation must occur before most types of exterior waterproofing for an existing home. French drain 1 installation includes the necessary minor excavation, but excavation must happen first for sealing or waterproofing the walls or backfilling certain areas. This is a long, labor-intensive process. It can take as long as 24 hours to excavate the home’s exterior. It must be done slowly and with care to prevent structural problems or collapse. Most costs include backfilling when complete.

Window Well Drain Installation

The cost of a window well 4 drain installation is between $500 and $1,500. Not every basement has a window well. For those that do, they are a frequent source of leaks. A window well installs on the window’s exterior. It is a drain that prevents the well from collecting water. When the water collects in the well, it seeps into the foundation at the base. With a drain in place, the water cannot collect.

Basement Leak Repair Cost

When you waterproof your basement, you have likely decided to do so after finding a leak. To waterproof, you must fix the leak first. Leaks can occur in many areas for many reasons. The most common are cracks in the foundation and hydrostatic pressure. A crack can allow groundwater in. Fixing this is between $350 and $500 per crack.

Hydrostatic pressure is a different story. This is pressure that builds up underground when the water has nowhere to go. It forces itself up and through your foundation, often causing cracks. You can repair the cracks, but more leaks happen if you do not address the cause. Fixing this involves a weeping tile or French drain and a sump pump 2. This has an average cost of around $5,500, plus the cost to fix any cracks.

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Basement Waterproofing Cost by Company

Some reliable material brands can help if you do not have serious basement water issues and want to do some waterproofing yourself. While it is always best to consult a professional before undertaking a more serious basement waterproofing job, some DIY materials help with issues like sealing walls and floors, repairing minor cracks, and directing rainwater from your foundation.

Basement Waterproofing Cost by Company: Drylok, Flex Seal, Crack, Seal-Once, and Underground Downspouts

Basement Waterproofing Cost by Company: Drylok, Flex Seal, Crack, Seal-Once, and Underground Downspouts

CompanyWaterproofing Cost
DRYLOK$0.60 - $1.00/sq.ft.
Flex Seal$1.20 - $1.50/sq.ft.
CRACK$1.70 - $2.00/sq.ft.
Seal-Once$5 - $6/sq.ft.
Underground Downspouts$25 - $30/spout

Cost to DRYLOK a Basement

The cost of using DRYLOK to seal a basement averages $0.60 to $1 a square foot. DRYLOK is a basement sealant material. It is a type of waterproof paint you can roll on yourself. It can cover your floors, walls, or both. It rolls on like paint and cleans up easily. It must be applied to clean, bare concrete. The concrete cannot have any other paint or material on it for the DRYLOK to be effective.

Cost to Flex Seal a Basement

The cost of using Flex Seal to seal your basement ranges from $1.20 to $1.50 a square foot. Flex Seal is a rubbery material you paint onto your concrete. When it dries, it creates a flexible surface that bends. This is good for homes with shifting foundations because it is less likely to crack. It is stiffer to apply than DRYLOK, so it may take a little more time. It can be applied to walls or floors.

Cost to Use CRACK to Repair a Basement

Using CRACK to fix the minor cracks in your basement costs between $1.70 and $2 a square foot. CRACK is designed to inject into small cracks in your basement walls or floor. It seals them up so that water cannot get through. If you seal your walls and floors, fix the cracks first. Use this material and seal over it. It has an easy one-step application and dries overnight. It can also be used on currently leaking walls to seal them immediately.

Cost to Use Seal-Once on a Basement

The cost to use Seal-Once in your basement is $5 to $6 a square foot. This is a basement channel sealing system. If you have a crack where the floor meets the wall and water is coming through, the Seal-Once system can fix it. This is a combination of flexible sealant material and flexible “baseboard” covering. You run a bead of the sealant into the crack and apply the cover. The process is easy but time-consuming and can take about a day.

Cost to Place Underground Downspouts

The cost of an underground downspout end is $25 to $30 per spout. This system helps keep gutter water from pooling near your foundation. If your current downspouts are causing the water to pool and flood back toward your foundation, burying the downspout can help. This is a simple system that can be installed DIY in a few hours. You dig a hole for the device, attach it to the end of your downspout to extend it, and sink the end into the hole. It keeps the water away from your foundation more effectively than standard systems.

Worker Waterproofing the Basement Foundation of a Home

Waterproofing vs Damp Proofing

Waterproofing and damp proofing may sound similar, but they are different. Waterproofing addresses the problems behind why the water is getting in and stops them. This could mean waterproofing walls, adding a drain system and sump pump, or a combination. Damp proofing only stops moisture from coming through the walls and floor. It does not address why it is coming through, so it is slightly less expensive. Waterproofing costs between $3 and $10 a square foot, while damp proofing costs between $3 and $6 a square foot. Damp proofing is also applied to fewer areas, so the total cost is usually lower.

Interior vs Exterior Waterproofing

Waterproofing your basement can be broken down into interior and exterior categories. Of the two, interior waterproofing tends to be less expensive. This is because it is less invasive to waterproof the interior in existing homes rather than excavate and expose the exterior. However, exterior waterproofing is more effective overall. If you are building a new home, exterior waterproofing is less expensive and more effective. In an existing home, you need to weigh the excavation costs against the benefits. In most homes, waterproofing the interior can take care of many issues.

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Enhancement and Improvement Costs

Water Damage Repair

Water can cause damage if it gets into places where it should not be. If water is not cleaned up properly or repaired within the first 24-48 hours, the damage can worsen. The average cost of a basement flood cleanup is $4,000, while the cost of repairing water damage is around $3,000.

Dehumidifier Cost

A dehumidifier can help keep your basement dry. Basements tend to be overly humid, which can cause surfaces to stay damp. A dehumidifier removes water from the air, which can keep your basement drier. Depending on the size and type, they cost $50 to $1,000.

Additional Considerations and Costs

  • Waterproofing a basement comes with a warranty offered by a contractor or a company. Usually, a warranty offered for waterproofing is anywhere between 10 and 25 years.
  • There may be removal costs for things like air conditioning units, decks, patios, fences, or driveways to complete the waterproofing.
  • A list of contractors and advice can be found through the Waterproofing Contractors Association.
  • Working from the outside on a deep foundation requires more labor due to the additional excavation needed.
  • Get more than one estimate for the job. Get at least three quotes to compare.
  • Make sure that the ground around your foundation slopes away from the foundation and not toward it. This helps drain water from the foundation.
  • For your gutters to function properly, they must be clean. Downspouts should discharge water at least 5 feet (1.5 m) away from the foundation.
  • Plants should be placed at least 12 inches away from the foundation on a slope to allow water to drain away from the foundation.
  • Obtain a permit for completing a project of this type. Depending on your area, a permit for your job may be required.


  • How do you stop water from coming into your basement?

You can stop water from coming into your basement by patching any cracks or gaps using cement, directing water away from your foundation, and adding drainage pumps.

  • Is basement waterproofing covered by insurance?

Basement waterproofing is not usually covered by insurance. It must be tied to another issue in most cases, and many people do not have things like flood damage or other basement water damage covered at all.

  • Can you seal a basement from the inside?

You can. It is not as effective, and you need clean, bare walls. They cannot currently have paint on them. This is a good solution if your exterior is difficult to access.​​

  • Does basement waterproofing increase home value?

Waterproofing does not necessarily increase a house’s value. Things like French drains and sump pumps may have a good return rate, depending on your area. However, most waterproofing is seen as helping your home maintain its value rather than adding value.

Remodeling Terms Cheat Sheet

Definitions in laymen's terms, cost considerations, pictures and things you need to know.
See full cheat sheet.
glossary term picture French Drain 1 French drain: An outdoor buried drain line that leads water away from the house. Water runs through a trench filled with gravel into a perforated pipe underneath, which leads the water downhill to a safe area
glossary term picture Sump Pump 2 Sump pump: A mechanical device used to remove water from wet areas such as basements and crawlspaces in order to help prevent flooding
glossary term picture Epoxy 3 Epoxy: An adhesive, plastic, paint, or other material made from polymers containing epoxide groups. Epoxy is best used for bonding or for creating a protective coating
glossary term picture Window Well 4 Window well: A semi-circular area around a window below the grade of the house, reinforced by a sturdy material such as galvanized metal or masonry

Cost to waterproof a basement varies greatly by region (and even by zip code). To get free estimates from local contractors, please indicate yours.

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