How much does it cost to waterproof a basement?

Reviewed by Cristina Miguelez remodeling expert. Written by Fixr.com.

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 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 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 by the square footage cost, such as sealing the walls and floors.

Basement Waterproofing Cost per Square Foot

The average cost of waterproofing a basement is between $3 and $10 a sq.ft., including materials and labor. This range is due to the enormous differences in waterproofing types and their varying costs. The most common types that are charged per sq.ft. include liquid and sheet membranes. Liquid membranes, such as waterproofing paint or stain designed for concrete, are a great choice if you have a smooth, clean surface. Sheet membranes, which offer a variety of styles and protection levels, are priced a bit higher than liquid waterproofing materials. If you have a lot of work done on your basement, you can calculate the project’s total cost in square feet. In the table below, you will see some common basement sizes and their corresponding costs for waterproofing with labor and materials included.

Basement Waterproofing Interior vs Exterior Prices

You will spend between $500 and $15,000 on basement waterproofing, depending on whether it is done on the interior or the exterior of the basement. 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 waterproofing is generally much cheaper than exterior work, which usually requires excavation and extensive prep work before the waterproofing begins.

On the low end of the price range, you can get minimal waterproofing on your basement interior or exterior. At the higher end of the price range, you will get the fullest, most effective waterproofing inside and/or outside of your basement. Several methods of interior and exterior waterproofing assist in drying out your basement, depending on your budget and other needs. In the table below, you will see a breakdown of the average costs of interior and exterior waterproofing, including all labor and materials, for a 1,000 sq.ft. basement. The low cost reflects minimal work or small projects, and the high cost includes many more steps in the waterproofing process.

Interior Basement Waterproofing Cost by Method

You can expect to spend between $0.50 and $7.00 per sq.ft. or $40 to $100 per linear foot, or $300 to $600 per sump pump or crack fill on basement waterproofing based on the method(s) used. Interior waterproofing offers many methods and material types that can waterproof the basement fully. 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. It is easy to waterproof the interior of existing homes, which is why it is the most common choice. The table and subsections below show a breakdown of the different interior waterproofing methods and their costs.

Crawl Space Vapor Barrier

A vapor barrier is a unique membrane available for basements and crawl spaces, costing between $0.50 and $0.70 per sq.ft. installed. This material is a durable plastic or composite membrane that lines the walls of the basement or crawl space to prevent moisture from penetrating the space. The standard thickness is about 20 mm. You can find vapor barriers that are thicker or thinner, depending on your needs. Thicker barriers provide premium protection but incur a premium cost. This is best installed by a professional and can be used to separate the finished basement space, including framing and drywall, from the concrete basement walls.

Basement Waterproofing Paint

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.

Basement Sealing

The cost to seal your basement ranges from $3 to $7 per 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.

Acrylic offers a permanent sealant and is the most affordable option. It is flexible but durable enough to withstand the shifting and movement of the foundation. 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 is another option that is a bit more expensive but offers more flexibility. It can be covered with another material, such as water-sealing paint. Epoxy is the last option and is a full-surface sealant. It is more complicated to install and changes the appearance of the floors and walls while providing moisture protection. In the table below, you will see a breakdown of the costs of each.

Interior French Drain Basement

An interior French drain costs between $40 and $100 per 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. The length of the drain and the amount of work involved impacts your weeping tile system cost.

Basement Sump Pump Installation

A sump pump installation costs between $300 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.

You can choose from pedestal or submersible sump pumps, depending on the type of drainage you need. Pedestal sump pumps are cheaper and do not require much effort to install. However, they can be noisier since they are not submerged in the water. This can also increase the risk of overheating. Submersible pumps sit under the water level and can pump out solids and other debris. They are generally more powerful. While they are a costlier investment, they offer premium protection.

Epoxy Injection Crack Repair

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.

Exterior Basement Waterproofing Cost by Method

You will spend $1 to $7 per sq.ft., $3 to $200 per linear ft., or $100 to $7,000 per unit for exterior waterproofing, depending on the method needed. This involves several methods and options and is easiest to do with new construction. 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 for those willing to invest the money and time. Some steps must be done together. For example, excavation must take place before sealing exterior walls or installing an exterior French drain. In the table below, you will see the average costs for each project.

Yard Grading

Grading the yard is a great way to keep water away from the foundation and will typically cost between $1 and $2 per sq.ft. if no fill dirt is needed for the grading process. If your yard slopes towards your house from the perimeter of your property, it could be leading water directly to your basement. Grading land away from the basement encourages water to flow away from the property and alleviates water damage or moisture issues in the basement.

Waterproofing Exterior Basement Walls

Waterproofing your exterior basement walls can be a good first step to controlling moisture and costs $3 to $7 per sq.ft. 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.

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.

Gutters

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.

Exterior French Drain for Basement

Exterior French drains, weeping tiles, or exterior drain tile systems cost between $10 and $100 per 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

The cost of exterior excavation for waterproofing averages $100 to $200 per linear foot. Excavation must occur before most types of exterior waterproofing for an existing home. French drain 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.

Underground Downspout

Installing underground downspouts is another way to assist with moisture removal in the basement and costs about $100 to $300 per spout, with $25 to $30 going toward the downspout and the rest accounting for labor. This job is usually performed by gutter installation services but can also be done by some roofers and general handymen, provided they have the right experience. This system keeps 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 in a few hours. The installer will 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.

Window Well Drain Installation

A window well drain installation costs between $3,000 and $7,000. 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 Waterproofing Prices by Company

You will spend between $0.60 and $6 per sq.ft. on basement waterproofing solutions depending on the company you hire. 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.

One popular option that is also affordable is DRYLOK. People enjoy that the cost to DRYLOK a basement is just $0.60 to $1 per sq.ft., saving a lot of money compared to other options. DRYLOK rolls on like paint and is easy to clean up. Flex Seal is also popular, especially for homes with shifting foundations. If there are minor cracks, CRACK is a good option, offering a one-step application. Seal-Once seals channels and ensures that the basement corners and cracks are sealed and protected. The table below shows a breakdown of the costs of each brand with labor included.

Basement Leak Repair Cost

Basement leak repair costs $350 to $4,000 for crack repair to as much as $60 to $80 per linear foot for the installation of a French drain. 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.

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.

Basement Seepage Repair Cost

Basement seepage is another indication that there may be a need for waterproofing in your basement and costs between $3,000 and $10,000 to repair. Seepage through the floor or walls or cracks in either can point to several potential issues. There could be cracks in the foundation, the yard grading could be wrong, or the home could simply be in an area that has a higher water table and is more prone to water getting into the space. Waterproofing against seepage usually requires crack sealing, surface waterproofing, and a vapor barrier or exterior membrane to prevent water damage and infiltration.

Wet Basement Causes

There are several different causes of wet or damp basements and crawl spaces. If they were dry, these spaces could offer storage or additional living space, so it is important to get to the root of the problem. Homes built in a higher water table or near bodies of water, for example, will have wet or damp basements in most cases because there is more water in the ground than inland. Wet basements can also be caused by cracks in the wall, leaky pipes, damaged gutters or drains, or even sewage overflows. In many wet or damp basement situations, the water comes into contact with the walls and the floor and could cause damage to appliances or personal belongings. Check your grading and gutters. Make sure that your plumbing is leak-free. Then, you will eliminate most of the causes of wet basements.

Waterproofing vs Damp Proofing

Waterproofing costs between $3 and $10 a sq.ft. Damp proofing costs between $3 and $6 a sq.ft. Damp proofing is also applied to fewer areas, so the total cost is usually lower. Although the processes sound alike, they are actually completely different. While damp proofing keeps moisture out of the walls and floor, offering a less expensive option, waterproofing is almost always the better option. Waterproofing addresses all the issues causing water to get into the basement and stops them by properly remediating the issues. This could include adding sump pumps and drainage, sealing the walls and floor, and so forth.

Enhancement and Improvement Costs

Water Damage Repair

The average cost of a basement flood cleanup is $2,000 to $7,000, while the cost of repairing water damage is between $2,000 and $85,000. 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 to 48 hours, the damage can worsen. Before waterproofing, there may be a need to repair water damage and clean up standing water, which is added to the cost of waterproofing.

Mold Remediation

If water damage leads to mold, mold remediation for your basement costs between $1,500 and $4,000. You will need to pay for professional mold remediation prior to waterproofing the basement to ensure that the space is safe and healthy for your family. This cost will be in addition to the price of waterproofing your basement.

Dehumidifier

A dehumidifier helps keep your basement dry. Depending on the size and type, they cost $50 to $1,000. 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. Some people install a dehumidifier along with their waterproofing efforts to ensure that the space maintains a good humidity level and does not cause future water damage issues.

Additional Considerations and Costs

• Warranty. 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.
• Removal and preparation costs. There may be removal costs for things like air conditioning units, decks, patios, fences, or driveways to complete the waterproofing.
• Contractors. A list of contractors and advice can be found through the Waterproofing Contractors Association.
• Deep foundations. Working from the outside on a deep foundation requires more labor due to the additional excavation needed.
• Quotes. Get more than one estimate for the job. Get at least three quotes to compare.
• Yard sloping. Make sure that the ground around your foundation slopes away from the foundation and not toward it. This helps drain water from the foundation.
• Gutters and downspouts. 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. Plants should be placed at least 12 inches away from the foundation on a slope to allow water to drain away from the foundation.
• Permits. Obtain a permit for completing a project of this type. Depending on your area, a permit for your job may be required.