Can You Fix A Leaky Basement From The Inside?

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Some basement leaks occur because of significant water damage or structural harm to the building. Upon seeing the excess moisture in the subterranean space, you start wondering if you can fix a leaky basement from the inside. We've done the research to bring you the answer.

Fixing a leaky basement from the inside is possible, but it may require professional help depending on the severity of the problem. If you find that you can repair the basement leak without professional help, follow these steps to ensure you won’t make costly mistakes:

  1. Identify the source of the leak in the basement.
  2. Fill the crack or hole.
  3. Seal with an appropriate sealant.

Many homeowners will experience leaks inside their basements. In some cases, these problems are minor and might only require relatively simple DIY solutions. Still, we encourage you to continue reading to learn the details on how to fix leaky basements to ensure optimal results. Without further ado, let's get into it.

Flooding rainwater causing damage on basement floor, peeling paint and mildew, Can You Fix A Leaky Basement From The Inside?

Fixing A Leaky Basement From The Inside

Rain water leaks on the wall causing damage

A leaky basement is a problem that can lead to other serious issues. The excess moisture may even invite pests to live in your home’s underground space. If you notice that there’s a leak in your basement, here are the ways to repair it:

1. Identify The Source Of The Leak

You may notice a foul, musty smell the moment you step into your basement. This stench might be because of mold and mildew growth, and you might find the smell as something similar to the odor of dirty wet socks.

However, simply smelling mold in the area isn’t enough to actually find the source of the leak. You can use the plastic test to help determine the source of the problem.

You’ll only need a utility knife, duct tape, and a plastic tarp or garbage bag for the test. Once you have the required items, follow these steps:

  1. Search the basement floor or walls for visible signs of moisture, which may include efflorescence, a formation that’s usually white emerging from subsequent precipitation caused by evaporation.
  2. Cut the plastic tarp or garbage bug into a square with the utility knife. Make sure that the material has appropriate dimensions to cover the source of the excess moisture.
  3. Wait for 24 hours and before removing the covering. If significant moisture forms underneath the tarp or bag after removing it, you found the area of your leak.

This test is ideal if the source of the leak is difficult to find. In some cases, you might immediately find a crack or hole in a certain spot in your basement that causes water to leak into the space. Once you locate the leak, you can proceed.

2. Fill The Crack Or Hole

Upon finding the leak, the next step is to fill the crack or hole. You can use an epoxy-injection system for this step. To do so, simply follow these steps:

  1. Make sure that the area in and around the crack or hole is dry as possible. Use a blow-dryer to speed up this process.
  2. Align the injection points by tapping a 3-inch nail into the problematic area.
  3. Mix the two parts of the epoxy crack sealer. Ensure that you’re following the product’s instructions to avoid making mistakes.
  4. Fill the base with the solution and allow it to cure. Take note that the solution can take different times to cure, depending on the product’s ingredients. Some options may cure in minutes, while others might take several weeks.

Click here to see this epoxy two-part adhesive on Amazon.

3. Seal The Problem Area

After the fill cures, reduce the risk of the leak from reoccurring by sealing the filled area. It's important to use the right type of sealant for this step.

For example, use masonry sealant if you’re dealing with bricks. You only need to use a brush to paint the masonry sealant on the area. Treat this solution like you’re painting a surface in your basement. Wait for the sealant to dry before painting it over to color match the space.

Click here to see this interior/exterior brick sealer on Amazon.

Does Interior Basement Waterproofing Work?

Replacing the old sump pump in a basement

Interior basement waterproofing techniques work if the cause of the water leak originates from inside the space. Sealing cracks and holes in different surfaces inside the basement can help prevent water from leaking into the area.

One excellent solution to reduce the risk of basement leaks and floods is to install an underground sump pump.

This machine is generally in the lowest part of the property, which also tends to be lower than the basement. It receives the excrements from the footing or perimeter tile to help remove excess moisture nearby.

Click here to see this submersible sump pump on Amazon.

What Is The Best Basement Waterproofing Method?

The word "best" is generally a subjective term, especially when talking about basement waterproofing methods. In other words, one homeowner’s best basement waterproof technique might not be the optimal solution for another property owner.

Still, some means of waterproofing a basement tend to work better than others. For instance, interior waterproofing might be the best solution to close cracks and holes in different surfaces inside the space.

On the other hand, certain basement flooding issues such as a poor soil grade because of a particular lot failing to meet a certain score may require other methods to help prevent basement flooding.

Click here to see this waterproof sealant on Amazon.

How Do I Stop My Basement From Flooding In Heavy Rain?

Big wet spots and black mold on the wall of the domestic house room after heavy rain

Excess water might drip from the downspouts and into your basement because of heavy rain. One of the best things you can do to prevent your basement from flooding is clean your gutters. Removing debris can help stop basements from flooding because of heavy rain.

Aside from cleaning gutters, here are some quick tips to stop basement floods caused by heavy rain:

  • Seal basement window wells with appropriate covers.
  • Ensure that the lot has a proper grading.
  • Check and seal any cracks or holes in the basement ceiling, floor, and walls.
  • Inspect and maintain the basement plumbing system frequently.
  • Check for blockages in lateral sewer lines and remove the obstructions if found.

For more information about stopping basement flooding from heavy rain, read through this post: Water Leaking Into The Basement After Heavy Rain – What To Do?

Will Flex Seal Stop Basement Leaks?

Flex Seal is a product line known to help repair different materials and surfaces, including aluminum, glass, fabric, cement, and porcelain. You can use these products to stop basement leaks, and here are the steps to do it:

  1. Pour an appropriate amount of Flex Seal into the problem area. You may use a brush or roller to cover a large surface area.
  2. Apply as many coats as necessary.
  3. Let the solution sit for 24 hours per coat applied.

Take note that Flex Seal may cure faster if the basement has proper ventilation, which is essential for many subterranean spaces. If you want to learn more about the importance of venting a basement, check out this post: How To Get Rid Of Sewer Smell In Basement Bathroom

Click here to see Flex Seal on Amazon.

How Much Does It Cost To Fix A Leaking Basement?

The cost to fix a leaking basement depends on the source of the problem. If the leak comes from a cracked foundation, the cost generally ranges from $1,500 to $15,000 depending on the severity of the issue.

Moreover, installing a weeping tile system or a French drain can range from $1,000 to $10,000 depending on the excavation accessibility and path. There might also be additional costs from the sealants used in the repair project.

Using concrete sealers is a fairly inexpensive option to close small cracks and holes, as these products have an average price range of $0.15 to $0.25 per square foot. But using professional help and applying silicate sealers may increase the fees to approximately $3 to $9 per square foot.

Click here to see this stone and concrete sealer on Amazon.

In Closing

Leaky basements can be fixed from the inside by finding the source of the problem. If the cause of the leak is a crack or hole in the space, fill it with caulk or concrete depending on the surface’s material.

Finally, seal the location with an appropriate sealant, such as a masonry sealant, to help prevent the problem from reoccurring. Good luck!

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