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On average, you can expect to pay around $3,000-$7,000 to professionally waterproof your basement, including labor costs.
Unfortunately, moisture problems and water damage are common issues for homeowners in most climates. Not only can a wet basement cause structural damage, but it can also lead to mold growth and other problems if left untreated. Depending on the severity of the moisture, you may be able to waterproof your basement yourself with cheap materials like sealants. For more serious situations, hiring a waterproofing contractor may be necessary.
There’s a variety of factors that could influence the cost – and other ways to waterproof your home. Let’s dig in.
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Basement waterproofing cost factors
The cost of waterproofing is $3-$10 per square foot on average. One of the biggest cost factors is the square footage of your basement. The larger your basement is, the more you’ll have to spend on materials and labor.
If you live in a damp or more volatile climate where hurricanes and snow are more prevalent, you’ll likely need to pay for repairs more often. Contractors may also be required to follow certain rules and regulations depending on local ordinances.
Older homes that feature stone or brick basements can be more difficult and expensive to waterproof due to potential cracks and damaged foundations. Contractors may have to use more expensive interior waterproofing methods like crystalline materials, in which crystals grow and expand to prevent water seepage.
Depending on the severity of the leak or water damage, the quality and quantity of materials will impact the cost for you or your contractor. Cheaper materials like concrete sealers can cost you less than $100, but keep in mind that these are temporary solutions.
If you’re on a tight budget, you may be more inclined to waterproof your basement yourself. But remember that any mistakes can lead to costly repairs in the future.
If you do decide to hire a professional, you can expect to pay anywhere from $500 to $15,000, depending on the size of the home and the whether you’re waterproofing the interior or the exterior of the basement.
The deeper your foundation is, the more time and money will be needed to fix it. Older homes that feature brick, clay, stone, or other expensive materials may cost more than concrete.
Types of waterproofing
Interior basement waterproofing
Image source: The Home Depot
Concrete sealers, acrylic waterproof paint, and silicates are more cost-effective than other waterproofing materials but are also considered more as temporary solutions. When combined with dehumidifiers, sealants are adhered to the interior wall and can help keep your basement dry. DIY sealants typically go for an average cost of $60, depending on the quality.
Epoxy injections are also considered a temporary fix. Epoxy is used like putty to seal up non-moving cracks. Depending on the size of the crack, these injections can cost $350 to $500 per crack and will need to be done by a professional.
Image source: The Green Cocoon
Made up of plastic or foil sheets, vapor barriers are another cost-effective option. Vapor barriers can be installed on the basement walls and can help keep moisture out. While vapor barriers can cost as little as $24 per roll that covers 120 square feet, they don’t have a very long lifespan and eventually disintegrate over time.
Image source: American Waterworks
Interior drainage systems like sump pumps and French drains are significantly more expensive, but also more efficient. Water is directed to the sump pit, and when the water reaches a certain level, it’ll pump the water out of the basement. If you don’t have a pit for the pump, a sump pump installation typically ranges from $700-$1,600.
French drains can be installed inside or outside your home, either directing water away from the exterior or interior of your basement. Interior French drains feature trenches filled with gravel along the sides of the basement. When it rains, the water seeps through the gravel and into perforated pipes covered with a waterproofing membrane and is directed away from the foundation. On average, French drains cost about $900 or about $25 per foot to install.
Drain tile systems, or “weeping tiles” are another form of French drain. In a drain tile system, a series of plastic pipes are placed underground near your home’s foundation. These pipes then direct the water away from your home. Drain tile systems can be installed either inside underneath the basement floor, crawl space, or outside around the foundation.
Basement windows and window wells can also be a likely source for leaks. In addition to installing a cover for the well, we also recommend installing a window well drain that can connect to the French drain or another drainage system.
Exterior basement waterproofing
Gutters and downspouts
Image source: Seattle Times
Perhaps the most common forms of exterior waterproofing are gutters and downspouts. We cannot stress enough how important gutters are in preventing water damage. Gutters collect excess water and flow into the downspouts, which direct it away from your home. Keeping your gutters clean and free of debris will help water from coming into your basement.
Image source: U.S. Waterproofing
Exterior foundation membranes are available in different forms such as liquid sprays, sheet rolls, and adhesives. These membranes consist of different types of rubber and plastics and are applied to your home’s exterior walls.
When choosing a type of waterproofing membrane, it’s important to understand if the system is above or below grade. Above-grade systems are for structures above ground level and below grade is for any part of the structure that’s below ground level. Above-grade waterproofing systems have to be breathable and resistant to corrosion and UV rays due to exposure to sunlight.
Below-grade systems have to be flexible, resistant to hydrostatic pressure, and have a low absorption rate. Waterproofing companies will likely analyze the area surrounding your home and refer to the soil characteristics and water table to determine if there’s hydrostatic pressure and if there are any chemicals in the soil. Water tables will help determine what type of waterproofing you’ll need and if it is required by code. Depending on how much you need, waterproof membranes can cost an average of $5 per square foot.
Causes of water damage
Gutters and downspouts are designed to direct water away from your home. So when they’re defective or clogged with debris, water then accumulates around the foundation and can seep through the basement walls. Make sure all of your gutters are free of any leaves or branches and you have enough downspouts for your home. Remember that you should have one downspout for every 35 linear feet of gutters.
While there are many different types and causes of foundation cracks, one of the more common reasons for vertical cracks is due to poor drainage. If your gutters are clogged and water begins to accumulate around your home’s foundation, the water can put pressure on the foundation walls and cause them to crack. Vertical crack repairs typically include epoxy injections, but for horizontal and step cracks, you’ll need an additional form of wall reinforcement such as carbon-fiber kevlar grid straps.
The most obvious cause of basement moisture is interior leaks from somewhere in the home. Household appliances and plumbing issues from dishwashers, toilets, showers, and leaky sinks can all potentially cause leaks in your basement. If you notice any wet spots or leaks from the ceiling, you’ll know where to look.
If your home is located on a negative slope where water runs towards the house, standing water can become an issue, leading to the deterioration of the foundation. Gutters and downspouts are designed to direct water away from the home, but other factors like soil and mulch can act like a sponge and make matters worse. With negative grading, it’s best to hire a landscaping crew or invest in waterproofing systems like French drains or sump pumps to help with excessive moisture.
DIY vs contractor
If you’re on a tight budget, it’s possible to waterproof your basement with sealants and dehumidifiers, but be aware that these are temporary fixes. While flood insurance covers water damage from natural disasters, your home warranty typically doesn’t cover any foundational issues like waterproofing. Basements are notoriously prone to moisture and water, which can lead to mold and other damages if left untreated. While it can be appealing to tackle the waterproofing project yourself, all of the potential risks for future damage make it important to take the extra step and hire a professional.
If you live in a wetter climate and experience frequent flooding or moisture in your home, it’s best to hire a professional to either install a drainage system or professionally seal cracks that prevent leakage. They’ll be able to also help determine and recommend which type of waterproofing is necessary and what may be required by local codes.
Basement waterproofing: in summary
Waterproofing your basement is an essential home improvement project that not only protects your home from water damage but also prevents health concerns like mold. Depending on how much you want to spend and the severity of the groundwater, there’s a variety of ways to go about it. Just remember to be aware of any moisture that’s entering your home, how you can prevent it, and determine the best way to handle it.