How Much Does Basement Waterproofing Cost?

• 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 sub-level, 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.

Labor

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.

Location

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 like a french drain.

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.

Home’s Age

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 cracked walls or floors 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.

Mold

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.

Landscape Grading

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.

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