How Much Does Foundation Waterproofing Cost?

Why Is Foundation Waterproofing So Important?

Moisture is the silent destroyer when it comes to your home’s structure. Water that seeps into your foundation can lead to cracks, mold, and other damage that can be very costly to repair. Preventative measures like waterproofing can save you a lot in the long run, with the added benefit of maintaining your home’s structural integrity.

The cost to waterproof a foundation mainly varies based on the size of your foundation. As a baseline, you can expect to pay between $5,000 and $10,000 to waterproof the entire foundation of typical 1500-2000 sq. ft. home.

There are other factors that can influence the total cost, though, including 1) the current condition of the foundation and 2) whether you want to add further protection measures while you’re at it. Below are some of the questions you should ask to get a better idea of what your foundation waterproofing will cost.

What Kind of Foundation Do You Have?

There are three main styles of foundation: 1) a full basement, 2) a crawl space, or 3) slab on grade. Most homes in the northern United States use a basement-style foundation. The further south you go, the more prevalent the other foundation styles will be. Basement foundations go the deepest, making them the most labor-intensive (and the most expensive) to waterproof. Waterproofing crawl spaces and slab on grade foundations requires less excavation on the exterior, making it easier and cheaper.

Does the Foundation Have Any Damage?

Existing problems will need to be fixed before the new waterproofing will be effective. Cracks or bowing in the walls in the home’s interior are often the first sign of foundation problems, though these can also be natural byproducts of the home settling and aren’t always cause for concern.

You can identify most foundation cracks just by giving a close look to the interior walls of your basement, but it’s a good idea to get a professional consultation before starting in on any major improvement projects, like waterproofing. This will usually cost around $150-$300, depending on where you live.

A few vertical cracks are normal in concrete foundations. These can be easily repaired with an injection of epoxy. Diagonal cracks are caused when the house settles unevenly, usually because it’s built on a slope, and can be repaired using the same methods as vertical cracks.

The big problem is if you notice any horizontal cracks. This indicates the foundation is bowing, and that can seriously compromise your home’s structural integrity. Horizontal cracks need to be fixed immediately, and the repairs can be costly.

Does Your Home Need Additional Protection?

If there’s a lot of ground seepage and leakage into your basement, a sump pump can help drain the water more quickly. The cost depends on how much square footage it’s covering, usually averaging out to around $10-$20 per square foot.

An exterior waterproofing membrane can also provide a layer of additional protection for homes that experience a lot of seepage in the basement. This is an impermeable barrier that is mortared to the exterior of the foundation, preventing water from ever making contact.

Finally, a better gutter system can help reduce the amount of water that reaches your home, making future leaks less likely. Replace any old, leaky gutters, and consider using downspout extensions so they drain at least 10 feet away from the foundation.

Is this something you can DIY?

The first step in foundation waterproofing is to excavate the home’s exterior all the way down—around 8 feet, in most homes with basements. Between the digging and the application of the waterproofing, it’s a project that could easily take up your entire summer. If you’re willing and able to do that amount of work, though, DIY basement waterproofing can cost as little as $2,000-$4,000, depending on what materials you use.

If you do plan to DIY, make sure you call 811 to get all utility lines marked before you start. You may want to get the foundation inspected, too. Major structural problems like bowing and horizontal cracks should also be repaired by a professional before you embark on any waterproofing project.