The Best Way to Waterproof Your Basem*nt (2024)

Most new homes are built with a properly graded lot and waterproofed basem*nt, but you may have to address this if you’re moving into an old house. While there are many ways to waterproof your basem*nt, the best option depends on what’s happening in and around your home’s exterior. We’ve compared interior and exterior waterproofing methods to help best resolve your moisture issues and keep your home structurally sound.

Method 1: Sealants and Epoxy Injections

Protect your basem*nt from moisture using a sealer on the walls and epoxy injections to fix cracks and gaps. The waterproof coating prevents the surface from getting damp and developing mold or mildew. Sealing basem*nt walls may also be an easy do-it-yourself (DIY) job because the product is just sprayed or rolled on the surface and left to dry. It’s similar to painting walls, but you must first remove any existing mold or mildew before applying.

Standard acrylic sealant is a cost-effective solution at $1 to $8 per square foot.* However, there are some restrictions. While sealants can be applied to concrete walls, they can’t be used over painted drywall. You’ll need to consider alternate solutions if your basem*nt is fully or partially finished. If your concrete walls are painted, you may need to strip the paint off first.

Another interior waterproofing method is epoxy injections to fix cracks and leaks in the basem*nt floor and walls. Epoxy is extremely durable in any setting and easy to apply. It costs $800 to $1,500 and can be outsourced to a professional or done as a simple homeowner DIY.

Benefits and Drawbacks

Using sealants and epoxy is a straightforward, inexpensive project, but it comes with some disadvantages. See an overview below.

Benefits

➕ Inexpensive
➕ Simple project to DIY or hire out

Drawbacks

➖ Doesn’t fix the root cause of a wet basem*nt
➖ Only lasts about 10 years

Method 2: Interior Drainage Systems

Installing an interior drainage system helps resolve water issues without damaging your landscaping. Sump pumps achieve this by pumping out standing water and directing it away from the basem*nt. There are two types of sump pumps: submersible and pedestal. A submersible installation is more difficult because it requires digging a hole into the concrete floor. For an easier installation, opt for a pedestal sump pump, which sits atop the basem*nt floor, instead of being submerged underneath it.

No matter which sump pump you choose, maximize its effectiveness by installing interior drain tiles. This waterproofing product reduces hydrostatic pressure caused by groundwater and protects your basem*nt walls and foundation from weakening under such intense pressure.

Sump pump installation costs $1,275 on average. Adding a drain tile system costs between $4,000 and $12,000.

Benefits and Drawbacks

Interior drainage systems waterproof your basem*nt without ruining your yard, but they’re costlier than epoxy and sealant. Here are some other pros and cons:

Benefits

➕ Addresses rising groundwater issues
➕ Leaves exterior landscaping intact

Drawbacks

➖ Doesn’t address how water gets into basem*nt
➖ Not easy to do in a finished basem*nt

Method 3: Exterior Waterproofing

Consider exterior waterproofing to fully protect your basem*nt and foundation walls from water damage and musty smells. Get gutters and downspouts installed if your home doesn’t already have them. Together, they divert rainwater away from your foundation without damaging your yard. Gutter and downspout installation averages $1,900 for an average-size home.

Another effective basem*nt waterproofing system is installing a French drain in your yard. A contractor will dig a trench on a downward slope in problematic areas of your yard and place a perforated pipe and gravel inside. This combination directs water away from your home and can also resolve standing water issues in your yard. The average cost of a French drain installation is $9,250.

You can also add exterior drain tiles with a sump pump for $4,000 to $15,000. Put them around your foundation to proactively pump water away from your house. This involves digging a trench around the home’s perimeter and filling it with several layers of washed gravel and filtration fabric. Sealant is also applied along the foundation to prevent water seepage.

French drains and drain tiles are two of the best ways to avoid major water damage under your house, but they also require heavy excavation work in your yard. It’s a larger investment of time and money, but the results are long-lasting.

Benefits and Drawbacks

Benefits

➕ Doesn’t interfere with a finished basem*nt
➕ Lasts decades with proper maintenance
➕ Prevents water from entering your basem*nt or foundation

Drawbacks

➖ Disrupts existing yard and landscaping
➖ Most expensive option
➖ Requires professional installation

*Unless otherwise indicated, all cost data in this article is from Angi and HomeGuide.

What Is the Best Way to Waterproof a Basem*nt?

Addressing water in your basem*nt should be a priority on your list of home improvement projects. The best waterproofing method depends on your home’s specific issues.

Sealants and epoxy may be best if the following apply:

• Your walls are unfinished, or you need simple window seal repair to keep moisture out.
• You want to eradicate mold and mildew growth in a damp basem*nt.

Consider interior waterproofing if the following apply:

• Rising groundwater is the primary issue causing moisture or standing water.
• There’s not enough excavation space around the exterior perimeter of your home (such as in a townhome or small city lot).
• Your basem*nt is unfinished with concrete floors and walls, making tackling a more invasive waterproofing project easy.
• You want to start with a less costly waterproofing alternative for your basem*nt.

Exterior waterproofing may be best for your project if the following apply:

• You already have a finished basem*nt and don’t want to disrupt interior waterproofing systems.
• You’re ready to invest in waterproofing your basem*nt as fully as possible.
• You want a damp-free basem*nt you can use as living space.
• Water runs toward your basem*nt from the outside.

Our Recommendation

The best way to achieve a dry basem*nt is to get a professional assessment of the causes leading to moisture under your house. While it’s easy to apply sealant and epoxy on your own, more complex drainage systems should be handled by an experienced professional. Consider getting two or more quotes for a consensus on how the water is currently entering your basem*nt and to get a better idea of local rates.