How Much Does Basement Waterproofing Cost? Basement Sealing Budgeting Guide
If there’s water in your basement, it will hinder how you can use it and can cause issues like mold and structural damage. Waterproofing is the solution, but how much does this project cost? Basement waterproofing costs can range anywhere from $2,250 to $7,063, with the national average at $4,539.
- Typical Range: $2,250 to $7,063
- National Average: $4,539
A wet basement is never a good thing. When groundwater or moisture make their way into your sublevel, it can cause unpleasant smells, mold, and concrete deterioration. Luckily, you can fight back against that moisture by waterproofing your basement. But how much does basement waterproofing cost?
Costs will largely depend on how you waterproof the space, as there are many options and techniques. Will you waterproof from the inside or out? Is excavation necessary? What products will you use? All of these considerations, and many more, will affect your budget and the outcome.
Waterproofing vs. Damp Proofing
There are two main types of moisture control used in basements: waterproofing and damp proofing. The terms are often used interchangeably, but they have totally different meanings.
Waterproofing is a method of keeping soil moisture and liquid water from penetrating a basement foundation or floor. This can be done with special membranes, cement coatings, and many other methods. According to HomeAdvisor, waterproofing basements costs between $5 and $10 per square foot.
Damp proofing simply fights soil moisture from soaking into the concrete, and most modern construction homes feature some degree of it already. It doesn’t do much for groundwater, but it can help a basement that would otherwise smell musty remain odor-free. If you have to pay for damp proofing, expect to pay between $3 and $6 per square foot.
Factors in Calculating Basement Waterproofing Cost
Like most home improvement and repair projects, basement waterproofing costs vary based on a myriad of factors. The cost of a contractor to handle the job is a significant portion of the total amount, but hiring for the job can mean avoiding headaches and often time in the long run.
Basement waterproofing cost also depends on whether the job includes waterproofing inside the basement or on the exterior. Size is a top consideration: Waterproofing larger basements will obviously cost more, but the cost per square foot might be lower than for a smaller basement.
Also, consider the products. There are premium products that do require some experience and expertise to apply, which will drive up the invoice. Some sealers are less expensive to purchase but more expensive to apply, and vice versa, so the products chosen will have a significant impact on the overall cost of waterproofing a basement.
One of the most significant factors in budgeting for a basement waterproofing project is the labor. Contractors have payroll and bills to pay, overhead to carry, and profit to make. However, a contractor handles all the headaches and will leave you with some reassurance that the project was completed correctly. There is the possibility that you can hire a professional for basement waterproofing without the help of a contractor, which can slightly reduce your costs. In many cases, the price of labor is included in the quote you receive from the professional.
If you live in an area of the country with a lower cost of living, the chances are that the price you’ll pay for projects will be on the lower end of the spectrum. The same applies to more expensive areas: Steeper cost of living leads to steeper job costs. But, if you live in a region prone to flooding and high water tables, basement waterproofing costs might be higher.
The contractors in those regions are in demand, as homeowners need to protect their investments by keeping water out of their basements. For that reason, those contractors can charge higher rates. If that seems unreasonable, realize that there is a greater risk involved for those contractors than contractors in drier regions.
Size and Layout of the Basement
While the method of sealing is probably the most significant factor in determining basement waterproofing cost, size is a close second. A large basement will require more material, more time, and more labor than a smaller basement. Layout can also be a factor, but less so than the square footage.
Interior vs. Exterior Sealing
There are two places you can stop water from penetrating basement walls: on the outside of the wall or on the inside. Interior sealing involves coating the inside of the basement walls with a waterproof sealant. Exterior sealing involves digging down below the grade, exposing the foundation, and coating it or protecting it with a waterproof membrane.
Exterior sealing is inherently more expensive. There is more labor involved, more equipment, and more time. But, it’s often the best way to keep water out of a basement.
Type of Sealant
Products and the methods used to apply them have varying costs. For example, coating the interior of a basement with an acrylic paint is relatively inexpensive. The materials are affordable, and the labor is no more involved than traditional painting.
Meanwhile, using an exterior membrane to keep water out of your basement will cost much more. These membranes, the adhesives to apply them, and the labor and expertise involved in installing them are expensive. This is also often the most effective method, though it’s rarely a DIY job.
Additional Costs and Considerations
The method and labor involved in waterproofing a basement are the most obvious costs, but there are some additional costs you might not be expecting. For instance, the material and the condition of a basement will be a factor. Block wall foundations often require additional materials, while foundations in poor condition need immediate addressing.
You’ll also need to consider factors such as the home’s age, any basement repair needed, and what you can do to prevent water from making it to the basement walls altogether.
All of these factors will have at least some effect on the cost of the project, and the more of them that are necessary, the more expensive the project will be. They’re all important to consider.
Foundation Material and Condition
Concrete and block walls are incredibly tough and durable, but they’re not indestructible. In fact, concrete blocks have large voids inside them that can collect water. For that reason, contractors might need to drill weep holes in the bottom and allow them to drain into a drainage track.
If the foundation is in rough shape, no amount of waterproofing will work, and the structure can actually be unsafe. In that case, you’ll need to have the walls repaired before you can move forward. The foundation repair cost will be extra, depending on how extensive the repairs are. But these repairs are crucial to ensure a waterproof foundation.
Your home’s age might have something to do with the routes you’re able to go with when waterproofing your basement. Homes built before the 1960’s might not have footers under their foundations, which are essentially concrete walls below the surface with flared “feet” to both anchor the foundation in the soil and disperse the weight.
If your home has footings, a contractor can dig down to those footings and install a water tunnel on top of it. This gives water a way to run off of the foundation wall instead of penetrating the wall.
Leak and Crack Repairs
Very often, the source of water and moisture in a basement is a crack (or several cracks) in the floor or walls. While the walls may still be strong and stable, water squeezes its way through those cracks from the soil outside, leaving your basement a dirty, wet mess.
Before ensuring a waterproof basement, those cracks need addressing. There are DIY kits that users can buy, but fully repairing the crack might require a professional’s touch.
The dreaded byproduct of water in a home: Mold. Mold spores exist everywhere, but damp, dingy, dark, wet basements are the perfect breeding ground for an infestation. Mold can, of course, cause serious health issues, so if you have mold in your basement, you can’t overlook it.
If it’s a very small section (under 10 square feet), you can attempt to tackle the job yourself. If not, mold removal is another cost that you’ll have to factor if you’re unlucky enough to harbor some in your basement. This type of work requires personnel specifically trained and licensed in mold removal. Mold removal can cost anywhere between $1,123 and $3,326.
Water Table Level
In some cases, simply patching a few cracks will be all the waterproofing you need to maintain a dry basement. But in areas with high water tables, the International Residential Code (an international guide for building safety) actually requires waterproofing.
The water table is the level below grade where the ground is saturated with water. There are many reasons why an area might have a high or low water table, but the former can be expensive to combat. These areas don’t shed rain or groundwater very well, and a basement is often the route of least resistance. For that reason, exterior waterproofing efforts might be the only option.
Interior Water Drainage
In some cases, it makes the most sense to control water rather than waterproof. For those applications, adding some interior water drainage methods might do the trick. This usually includes excavating a small trench (around 6 to 8 inches deep and wide) that slopes to a drain or a sump pump.
In the case of block walls, interior drainage is quite popular. Cutting and removing the concrete along the base of the wall and carefully drilling weep holes allows the trapped water to drain into a control channel. The sump pump or actual drain will remove that water from the basement.
Homeowners might not want to hear it, but their landscaping could be doing more harm than good. And even if it isn’t the cause of a flooded basement, some well-planned regrading can help reduce the issue. Regrading the landscaping around a home can help the home shed water away from the foundation before it can soak in. This can go a long way toward waterproofing a basement, but it takes special engineering skills and knowledge of soils and aggregates. A typical grading job can cost between $971 and $2,990.
Gutter and Downspout Additions
Some homeowners don’t understand the important role that their gutters play in keeping the basement dry. In some cases, that’s their main purpose. Without gutters, the massive amount of rain that a roof can collect in a rainstorm will drip down the shingles and land no more than a foot from the foundation walls—a perfect recipe for a wet basement.
Ensuring that your gutters are pitched correctly and free from clogs and debris is essential, or else water will back up over the brim of the gutter and drop in front of the foundation. Also, downspouts need to shed the collected rainwater at least 8 feet away from your foundation. Installing exterior or interior drainage, and ensuring your gutters are operating as they should be, are all important points to think over. These costs can run up to be a few hundred dollars.
Many of the solutions or situations listed above require excavation to solve the issue. Whether it be exterior waterproofing via a membrane, installing a water channel, or regrading the landscaping, they all require some knowledge and heavy equipment. Even if you rent the equipment and do it yourself, it’s an expense you need to factor into your basement waterproofing cost.
Excavation companies know how and where to dig without causing more issues than they’re solving. They’re also insured, which means that anything that could potentially go wrong will be on them.
Basement Waterproofing Cost: Basement Waterproofing Methods
There are several ways to waterproof a basement, and they take place on both sides of the wall. For instance, exterior waterproofing could include laying a membrane against the foundation walls below grade or installing a drain system on the footer. Unfortunately, these particular methods require excavating and can be a handful for a DIYer.
There are different methods to use on the inside. Pros might dig trenches around the perimeter of the basement and install drains for groundwater to run through. There’s also the possibility of sealing the walls with a waterproof coating.
Exterior sealing involves working on the outside of the foundation walls. Because most of the foundation wall is typically buried below grade, this requires some excavation and careful digging. There are also different types of waterproofing materials used on the outside of the foundation, each with its own application method and tools. Sealing a home’s exterior has a wide range of options and costs, costing up to $15,000.
- Cement waterproofing: Cement waterproofing involves mixing bags of cementitious mix and coating the surface with a thick layer. This is an easier and less expensive method than most other options, but the results can be hit or miss. The concrete mix doesn’t always adhere, and if the foundation settles or shifts, it’s likely to crack. Depending on the size of the home, cement waterproofing can cost between $1,000 and $1,500.
- Foundation membrane: Foundation membranes are the heavy-hitters of the exterior waterproofing game. These membranes are thick sheets of rubberized asphalt on waterproof polyethylene film. It has to be installed just right in order to work properly, but it’s usually the most effective method of exterior basement waterproofing. Beware that this method is pretty expensive, costing up to $15,000.
- Weeping tiles: “Weeping tiles” is a somewhat confusing term, as they aren’t tiles but pipes with a series of holes drilled in them. They install below ground around the perimeter of a home. Once water enters the holes, the pipes drain it away from the foundation, removing it before it has a chance to penetrate. This is sometimes the most cost-effective and DIY-friendly option, but it doesn’t always solve the issue. The cost to install weeping tiles can be between $100 and $250, depending on excavation and depth.
- Bentonite clay: Bentonite clay is an extremely absorbent material that can grow to 15 times its original size when saturated with enough water. And, once it hits its maximum size, it becomes so dense that water can’t travel through it. Waterproofing with this clay includes laying it along a trench outside the foundation, but it requires a lot of bentonite clay. It can also be installed between two porous sheets that allow water to pass through the sheets but not the clay, though this often requires an expert touch. Bentonite clay waterproofing costs a national average of around $3.50 per square foot.
You can also waterproof a basement from inside. In general, this includes either sealing off the surface with a waterproof paint, controlling the flow of water into a drain, or keeping moisture from settling within the space. Each solution has its place, so it’s important to consider them all.
- Coatings: There are certain coatings that DIYers and pros can use on the side of a basement wall and floor to keep water from making its way in. They’re either concrete-based or an acrylic/epoxy mix. The concrete is less expensive, but the acrylic or epoxy mix adheres better and is totally waterproof. You can expect to pay between $3 and $12 per square foot.
- Silicate concrete sealers: Another attractive option includes using a silicate concrete sealer, which penetrates into the concrete surface and causes a chemical reaction that makes the concrete much less absorbent. These products are inexpensive and relatively easy to apply, and since they penetrate, they will hardly change the look of the wall when dry. The materials might only cost $0.15 to $0.25 per square foot, but professional installation bumps the price up to $3 to $9 per square foot.
- Paint: The easiest and usually least expensive option for waterproofing is painting the interior walls and floor of the basement with a waterproof paint. These paints are typically acrylic-based and adhere well while also creating a barrier against water. Application is as easy as with typical painting methods. Most basement waterproofing paints only cost $30 to $40 a gallon, and they’re easy to apply.
- Vapor barrier: When it’s moisture that’s an issue, not necessarily water flow, a vapor barrier might be all it takes to waterproof a basement. These plastic sheets keep moisture on the outside instead of letting it into the house. They can be installed on the inside of concrete walls and floors, but also in basement crawl spaces. A vapor barrier installation can cost between $1,500 and $3,000.
- Baseboard channels: Baseboard channels are an attractive option for block walls; the installer can drill a few weep holes in the wall and then cover them with the baseboard channel. The channel acts as a gutter and runs toward a sump pump or train, keeping the rest of the basement dry. This process can cost around $30 per linear foot for a professional.
- Subfloor drain tile system: Finally, you can protect your finished surfaces by lifting them up off the ground with a subfloor drain tile system. These interlocking tiles are made from waterproof materials and offer an inch or two of space between the concrete floor and the finished floor above. This option does nothing to stop the water from entering the basement, so a moisture barrier is required. Expect to budget $25 to $55 per square foot.
Basement Waterproofing Cost: Do I Need Basement Waterproofing?
Luckily, not all basements require waterproofing. In most cases, the standard damp-proofing methods can keep the basement dry. But if you’re unsure if you need basement waterproofing, there are some telltale signs to look for that will tip you off.
Typically, you can look for stains on the walls or floor and they’ll tell you water was present. Discolorations in carpets, drywall, and wood surfaces would tell you that the water level either rose enough at one point to cause an issue or that you’re experiencing frequent leaks. You can also keep a nose out for musty odors.
Any of these signs would tell you that you need to consider some waterproofing. If you don’t, you’ll never be able to use the basement for proper storage or a finished space. Also, those odors might be a sign of mold, which is not something you want hanging around your subterranean spaces.
Water Stains on Basement Walls and Floor
If you’re noticing stains on the basement walls, floors, wood, or carpets, it’s usually an obvious sign that water was present and you should consider some sort of waterproofing to prevent it. Keep track of where those stains are, as you might be able to make waterproofing repairs in that area alone.
Efflorescence can look scary, but in and of itself, it’s rather harmless. This white, powdery substance is actually crystallized minerals (namely salt) that remain from after groundwater penetrates the basement walls or floor and then recedes. While the efflorescence is harmless, the water that brought it there might not be, and you should consider waterproofing.
Other than wet, soaked surfaces, musty odors can be the telltale sign of water in a basement.
Aside from finished spaces, basements aren’t particularly cozy. But they don’t become stinky and musty without a reason. The stale, soily smells can also be a sign of mold, so it’s probably a good time to find the smell and consider some waterproofing.
Water Accumulation Outside
If you’re noticing water accumulating on the outside of your home, whether it be the garden beds, the driveway, or even puddles in the yard, it can be a sign of a high water table. While the table might ebb and flow throughout the year, this might be a sign that you should think about waterproofing.
When you think of concrete basements, rust might not be the first thing that comes to mind, but it’s certainly worth watching for. The humidity caused by water in the basement will settle on every surface, including steel drain pipes, metal pipe hangers, and other metal surfaces. That moisture will cause corrosion, so if you’re seeing rusty metal in your basement, there’s a good chance you’ve got a water issue.
Basement Waterproofing Cost: DIY vs. Hiring a Professional
Waterproofing a basement is a big project. While it can be within the capabilities of some very experienced DIYers, it’s not advised for the average homeowner, and it might be best to hire a professional. A contractor will be able to identify where the water is coming from and decide which method and products are the most appropriate. They’ll also be able to handle repairs on the exterior of the home, including excavating around the home and installing the waterproofing products properly.
And proper installation definitely matters. For many waterproofing systems, the manufacturer requires a licensed professional to install them. They’re so serious about this that they won’t warranty the product if a professional contractor didn’t install it. That means you could potentially rent the equipment and spend the time digging and waterproofing the basement only to find that it didn’t work and your finished basement flooded. Homeowners insurance may or may not cover the damage, but you’ll have to pay to have the entire basement waterproofed again, and you won’t be reimbursed for your time.
Basement Waterproofing Cost: How to Save Money
There are some simple fixes you can undertake to save some significant money on basement waterproofing cost. For one, it’s a good idea to handle any small cracks with a concrete crack sealer so you’re not paying a contractor for something straightforward and simple.
You can also save yourself quite a bit of money by sorting out your gutters. In many cases, the water in the basement can be tied to clogged or leaky gutters, or gutters that don’t drain far enough away from the home. You might be able to forgo additional waterproofing altogether if you get those gutters squared away.
Also, consider where the water is coming from. In some cases, if the leak is localized to one area, you might not have to waterproof the entire basement. This is most common in houses built into grades where the foundation is buried on one side and exposed on the other. It’s very likely that the water will be coming in from the buried wall and not from the exposed side at all. In that case, waterproofing one wall will take care of the issue.
- Take care of small repairs yourself instead of paying a contractor to do it.
- Sort your gutters and ensure that the downspouts are draining 8 feet or more from the basement.
- Only waterproof the areas that are leaking.
- Finally, don’t ignore the warning signs: If you see signs of water damage in your basement already, it’s best to take care of the problem straight away. Letting the damage fester can lead to higher cost of repair later down the line.
Questions to Ask About Basement Waterproofing
If you decide to hire a contractor, you’ll want to ask some important questions before landing on one. For one, you’ll want to ask if they’re insured. If any excavating needs to occur, having an uninsured contractor is a recipe for disaster.
It’s also important to ask them for references for homes in which they’ve carried out similar repairs. Speaking to another homeowner about the experience of working with the contractor and any issues they might’ve had will tell you quite a bit about the contractor.
Also, ask what products they use, and do some digging into their reviews. The contractor might be an excellent person with top-notch craftsmanship, but if they use a product that’s prone to failure or doesn’t last as long as you’d like it to, it might be worth shopping for another contractor. If not, you can at least request they use another product. Some questions to ask are:
- Can I see proof of your insurance?
- Do you have references for similar projects?
- Which products do you use?
- Can you explain why this basement waterproofing method is right for my home?
- Do you offer a warranty on your work?
With all that background on basement waterproofing costs, there might be some additional questions bubbling up. This section will address them, as it’s a collection of the most frequently asked questions on the topic.
Q. How can I stop water from coming into my basement?
There are many different ways to waterproof your basement, including:
- Adding interior coatings
- Cutting drains into the floor
- Regrading your exterior landscape
- Installing a waterproof membrane on the outside of your foundation
Q. Can I seal my basement interior?
You can absolutely seal the interior of your basement. This is best done with a sealer or special paint with an acrylic or epoxy base. It’s also a good idea to use a concrete crack filler to take care of any cracks or separations in the floor or walls of your basement.
Q. Is basement waterproofing covered by insurance?
Most homeowners insurance policies will not cover waterproofing expenses. Some won’t even cover damages from flooding or water seepage, so insurance might not be an answer to your water issue.