How Much Does It Cost to Waterproof a Basement? (Updated in 2025)

Of all the parts in a house, it’s usually the basement that “takes the hit” during a flood. Then you’ve got burst pipes, clogged tubes, and overflow, not to mention termites. So, unless you want water/humidity to take over your basement and ruin it, do consider waterproofing it. While it won’t be cheap, in the long run, you will greatly benefit from this.

What’s the average cost of waterproofing a basement? What’s the best way to do it? Does the price differ depending on where you live? Can the average homeowner waterproof a basement on their own? What additional costs should you expect? And finally, do insurance companies pay for water damage in the basement? The average cost in the States is $3,000–7,000, with most homeowners paying around $5,000. Keep reading as we explain further.

The Importance of Waterproofing the Basement

The main goal of waterproofing is to protect the walls and the floor from water penetration which leads to decay, rot, and insects. If you live somewhere in the American South, floods can be a big issue. This won’t happen overnight, of course, but slowly yet steadily, constant exposure to water will damage the structural integrity of the house, not to mention cause health problems.

Besides, even when it doesn’t rain, and there’s no physical contact with water, abnormal humidity levels will still do a number both on the basement and the foundation. The bottom line is—without proper waterproofing, it will be almost impossible to protect the basement from rot, mold, and deterioration.

How Much Does Professional Basement Waterproofing Cost?

This greatly depends on the size of the basement, the location, materials, techniques, and more. That’s exactly why the price range on this is so wide. With that said, the average cost in the States is $3,000–7,000, with most homeowners paying around $5,000. If you’re on a tight budget and only want to seal the interior walls and maybe fix some cracks here and there, that will cost $700–1,500.

In contrast, a full-fledged waterproofing system that includes not only sealing but also installing a sump pump, drainage system, and some extras will set you back $10,000–15,000. The first thing to do before contacting any contractors is to measure the size of the basement in square feet or linear feet and assess the damage (if any) to the interior. This way, you’ll know in advance approximately how much you’ll have to pay:

Basement Waterproofing Cost By Different Regions

The United States is one of the biggest countries in the world with a very diverse pricing policy. For someone that lives on the West Coast, the cost of waterproofing a basement on the East will seem a bit too steep. The Southern states, in turn, are usually relatively cheap, with the Midwest sitting right in the middle and offering services at a reasonable price.

Basement Waterproofing Cost By Square Feet

As mentioned, before you get any work done, you need to grab a measuring tape and, well, measure the size of the basement in square feet. You do that by multiplying its length by its width.

Interior vs Exterior Waterproofing

Should you “fortify” the basement from the inside or the outside? Exterior waterproofing has proven to be more effective than when it’s done from the interior. But, it’s also more expensive. If you’re just laying the foundation for a future home, it will be much easier to make it water-resistant from the outside. Interior waterproofing, in turn, is more common for existing houses.

Sealing is the most common choice, along with installing a sump pump and maybe a French drain, also known as a weeping tile. But wait—can’t you waterproof the basement’s exterior after it’s built? Technically, this is possible but can be very dangerous and will cost significantly more. On average, interior waterproofing costs $500–10,000. To seal the exterior, you’ll have to pay $3,000–15,000.

Basement Interior Waterproofing Cost By Method/Technique

Alright, now let’s focus on the available options when waterproofing the basement from the inside. If you’re on a tight budget, using water-resistant paint will be your best bet. Sealing is relatively cheap as well. Acrylic sealants are available for $3–4 per square foot. Silicate is a bit more expensive ($4–6), with epoxy being the priciest pick ($5–8). For the best results, it’s common for homeowners to combine different solutions:

Basement Exterior Waterproofing Cost By Method/Technique

To successfully fight floods and other disasters, you need to waterproof the exterior. Earlier, we mentioned that exterior waterproofing is very expensive and dangerous when performed on an already-built house, and that’s very much true. For exterior wall sealing, you will have to dig the soil out, apply the solution, and put all the dirt back in. You can go with sheet membranes ($3–8) or liquid membranes (a bit cheaper, $3–7).

Bentonite sheets ($3–5) are also available. With that said, there are some great options that don’t require accessing the foundation in any way, like gutters:

Additional Costs to Anticipate

Waterproofing a basement involves installing a French drain, and gutters, sealing the walls, painting them, and using epoxy against cracks—we already covered that. So, what about extra costs? Are there any additional expenses involved? The answer is yes, but the list isn’t that big:

Can You Waterproof a Basement Manually?

If you don’t want to pay a contractor, you can try and waterproof the basement on your own. As long as the job doesn’t involve excavating or installing a French drain or a sump pump, it shouldn’t be very hard to handle. We’re talking about using waterproofing paint, sealant, epoxy, or even installing a set of gutters.

Sealant materials are easy to roll on; paint takes even less effort to apply. There are lots of decent-quality and cheap options on the market, including Drylock (a sealant), Flex Seal (a rubberized paint), and others. If the damage is minor, these solutions can be quite effective at dealing with it.

Does Home Insurance Cover Water Damage to the Basement?

It all depends on where you live, the local laws (both state and city), and the nature of the damages. The good news is—most insurance companies will pay for water damage to the basement. However, you’ll only be financed when the damage is sudden. We’re talking about burst pipes, broken appliances, and localized overflow.

If the damages were caused by poor maintenance and/or aren’t accidental (the basement is just old and rotten), don’t expect the company to pay a single penny. And what about natural disasters like flooding? This one’s a bit tricky, as it doesn’t always fall into the same category as heavy wind, fire, or thunder. Most standard home insurances don’t cover flooding. For that, you’ll have to opt for flood insurance.

If you live in a humid area that’s vulnerable to flooding or any other natural disaster, we’d recommend getting in contact with your insurance company in advance. This way, you’ll know exactly what to expect from them in case your basement does, indeed, get overwhelmed by water, or something worse happens.

Conclusion

Waterproofing a basement doesn’t take forever—you’ll be done in 3–5 days max. On the downside, it does cost a pretty penny and usually involves hiring contractors. The prices aren’t unreasonably high, though. And by doing this, you’ll be able to protect not only the basement but also the entire house, saving yourself a headache and expensive repairs.

So, yes, if you live in a hot and humid area, it’s very much recommended to start saving up to get that basement waterproofed. The sooner you do it, the longer the basement will last and the higher the resale value of the house will be. Besides, you’ll get to spend more quality time down there with the moisture gone for good!

Featured Image Credit: Pisaphotography, Shutterstock