How to Repair a Foundation Leak?

Kenneth Wilson

Most homeowners have to face a lot of problems with their home’s foundation from time to time. Well, a foundation leak is one of the most common problems. So, if you’re facing this, you might be curious to know about foundation leak repair methods. This article will help you get rid of your curiosities.

To repair the foundation, you must first identify and investigate the source of the leak. Then, to fix the foundation leak, you must dig around it, deal with the cracks, apply a waterproofing seal, and install a drainage pipe.

However, before starting the process of repairing a foundation leak, you must thoroughly understand each step. Besides, you have to recognize the warning signs to understand if you are having a foundation leak issue or not. So, in this article, I’ll go over the signs of foundation leak, different repair methods, as well as discuss all the steps of repairing a foundation leak.

What Causes Foundation Leaks?

Water pressure is no doubt one of the main reasons for foundation leaks. However, the clay bowl effect is also another major cause of the leaks in the foundation.

Hydrostatic Pressure

Well, hydrostatic pressure is one of the two forms of water pressure. It occurs when heavy rains or storms soak the soil, allowing fluid to be forced through the foundation’s walls or floor. Since the ground surface gets saturated during heavy or continuous rain, soil can not absorb extra water. Thus, the water table rises eventually.

Once the water table rises beneath a foundation, hydrostatic pressure gets on the foundation from underneath, forcing water into the basements and causing leaks.

Lateral Pressure

It is another term for sideways pressure. Flooding can occur when the softer soil around the foundation absorbs an excessive amount of water. The soil surrounding a foundation between both the pilings and the ground might absorb water as well, although it should drain under typical weather circumstances. 

Sand and loam, for example, drain rapidly and don’t retain much water. Clay soil, on the other hand, does not drain well and absorbs water, causing it to expand. So, when the soil spreads, it causes lateral pressure, which can cause foundation issues. The issues might lead to leaks in the future. 

Clay Bowl Effect

The foundation started with a massive hole in the ground that was eventually filled in with footings. The new soil used to fill the space is less dense than the original. However, rainfall can cause the loose soil to accumulate. Thus, the softer soil absorbs far more water than the compacted soil around it, resulting in a “clay bowl effect.”

Because of the bowl effect, groundwater will accumulate around the foundation and flow in through porous foundation walls or cracks and gaps of the foundation.

What Are the Signs of a Leaking Foundation?

Visible cracks in your home’s foundation, mold growth, uneven and buckling floors, etc., are a few of the most common signs of a leaking foundation. Unexpected water bills and squeaky doors and windows might also indicate a leak in the foundation.

Let’s discuss the most common signs of a leaking foundation:

Mold Growth

Molds are ubiquitous organisms that thrive in moist areas of the environment. If a foundation leak causes standing water, your home’s floors are likely to be affected. The water then can also be absorbed by your walls and every rug or carpet you have. Well, all of these areas are ideal for mold growth.

Sometimes people can see mold or fungus, while others might simply smell it. However, look for other signs of a foundation leak if you notice mold or mildew, which has a musty odor.

Visible Cracks

Cracks are one of the most revealing signs that there might be a leak or an issue with the foundation. If you detect cracks that run in several ways and are larger than inches, it would be best if you seek the help of a professional. Professionals will visit your property and inspect it, using several leak detection methods to see if there is a probable leak.

Buckling Floor

If your vinyl, laminate, or hardwood flooring is buckling, it might be an indication of a severe foundation leak. Because moisture is a foe of most of the flooring types, a water leak is the most common cause of buckling floors. Although there are a variety of causes behind dampness in your property, the most problematic is a foundation leak.

So, if you see major buckling of the floorboards in multiple sections of your house, you need to get it examined to ensure there is no leak in the foundation.

Rotten Woods

Rotten wood is also a common sign of a foundation leak. If water leaks into the house, it has to go somewhere. So, it could form puddles on the ground or absorb into the wood. When wood is exposed to water regularly, it begins to decay. 

If you detect decaying wood, you may have a big problem. It’s because rotten or decaying wood indicates not only the possibility of a foundation leak but also a serious foundation problem.

Uneven Floors

If the floor of your home is uneven, it might indicate that you have a leaking foundation. The floors could be uneven in a room or twice, or even all around the house. 

Whenever a foundation leaks, it’s usually due to too much moisture in the soil across the house. The foundation will shift as a result of this, as will the pressure on the house. Uneven floors are possible due to shifting loads. So, uneven floors are a sign of foundation leaks for sure.

Squeaky Doors and Windows

Well, as I have mentioned, when there are leaks in the foundation, the foundation shifts, which might affect the structure of your house. So when the structure begins to shift, the load on the home changes, making it impossible to open particular windows or doors. Thus, if a window or door suddenly becomes difficult to open, look around the house for other indicators of leaks.

Unexpected Water Bills

The most typical method to discover a foundation leak is through unexpectedly high bills of water. The majority of us have monthly water costs that fluctuate very little. So, the water bills are generally consistent over the year since people consume the same quantity of water.

So, you might have an idea of your water bills for every month. However, if your water bill is unusually high one month for no apparent reason, it is possibly due to a foundation leak in your house. 

How Much Does It Cost to Repair a Foundation Leak?

The average cost of repairing foundation leaks ranges from $2,000 to $7,000. However, the cost can be more or less depending on the cause and severity of the leaks.

Moreover, the cost varies depending on how much manpower, equipment, and time is required to fill the cracks, and seal


As low as

and cover the foundation using waterproof material. Well, a couple of leaks can indicate a major drainage and moisture issue in your property. 

To resolve this problem, you must speak with a specialist about different waterproofing measures that might improve the structure’s security. They’ll almost certainly advise you to seal your foundation.

Since the expense of this repair depends on the severity of the foundation leaks, it is not possible to estimate the exact cost. If your foundation only has a few minor leaks, it will not cost you more than $1,800 to repair the foundation leaks. However, if the leaks are severe and many parts of your house got damaged due to the leak, expect to pay around $10,000. 

Equipment Needed to Fix Foundation Leaks

Okay, so you’ve decided to fix your foundation leak. But, you can’t do it without the proper gear. So, let’s take a look at the things you’ll need: 

  • Shovel
  • Thick Brush
  • Towel
  • Cement
  • Latex or Epoxy Waterproof Solution
  • Drainage Pipe
  • Loose Gravel

How to Fix a Foundation Leak? (Step-by-Step Guide)

You have to find the source of the leak, dig around the foundation, pressure wash the foundation, apply plastic sheets, and deal with cracks to fix a foundation leak.

Now, let’s discuss the step-by-step process to fix a foundation leak:

Step 1: Determine the Source of the Leak

First of all, you have to find the source of the leak, inspect the area, and determine the cause of the problem. Determining the exact cause will help you to follow proper steps to solve the problem. 

So, check for wet cracks and stroll around the home to find the spot where water has entered from the outside. You’ll have to utilize a different procedure if you notice water pouring into the foundation from within as it means a plumbing problem in your home.

Step 2: Dig Around the Foundation

Dig around the foundation with the shovel. It would be best if you dig around 5-6 feet to the foundation. The trench’s breadth should be sufficient to complete the remaining stages at the bottom. You’ll require enough room to repair the foundation and lay the drain pipe.

Step 3: Pressure Wash the Foundation

If the pressure of the water does not remove all debris from the foundation, wipe the surface of the foundation wall with a thick brush. Create a little inclination in the patched portion, sloping it upward towards the wall from the floor. 

It gives the patched region more strength and aids in the drainage of any future dampness. However, let the foundation dry completely before starting the next step.

Step 4: Patch the Cracks

Now, it’s time to deal with the cracks. You would need a cement mixture to fill out the cracked area properly. 

Using a regular trowel, apply a little amount of the cement mix to the cracked area and level it out. Let the cement dry completely. For better results, apply a second layer of cement after the previous layer dries out.

Step 5: Use Waterproofing Paint Sealer

You can treat the foundation walls with latex or epoxy waterproof mixtures. You will only have to add water to the majority of these combinations. 

However, don’t forget to follow the manufacturer’s directions carefully if you use this sort of combination.

Step 6: Install Drainage Pipe

If you want to prevent foundation leaks in the future, you must ensure a good drainage system around the foundation. 

To keep groundwater away from the walls, install a drainage pipe around the foundation. It would be best if you put the pipe in a bed of loose gravel to prevent dirt from getting into it.

Preventing Foundation Leaks 

Prevention is better than cure. Taking the right preventive measures will result in saving a lot of repair costs in the future. So, here are some ways you can prevent foundation leaks. 

Water Proof Your Walls

You can install a French drain to reduce some of the hydrostatic pressure. This is sort of a huge project that might cost you up to $24,000 or even more. But it is well worth it in the long run. As the numerous times you’ll need to fix your leaks the total repair costs will eventually exceed that. 

Maintain Footing Drains

Check your footing drains often to see if they need repairs. Check if they have any damage or clogs and take appropriate measures.

If you don’t have footing drains you can opt to install curtain drains. These are not very expensive to install. So if you don’t have footing drains you can easily install these. 

Plug Up Cracks

Check for any cracks or leaks in your walls regularly. If you see any just plug them up with some quikrete or cement. This will prevent further damage to your walls even though it might not totally fix the issue. 

Clean Gutters Regularly

Keeping your gutters clean will ensure that your foundations are in tip top shape. As we’ve already discussed, interruptions in the drainage system is the primary cause of foundation leakage. 

So, keeping your gutters clean will ensure proper flow of water and that will keep your foundations looking fresh. You can also try adding gutter extensions to upgrade your drainage system. 

Why Hire A Professional?

To all the DIY handymen out there I’m sure you’d like to take matters into your own hands. But would that really be a good idea? You're gonna have to buy the right equipment and spend a considerable time of your day fixing your foundation leak. 

And on top of that if you make a mistake it might just become a really costly one. So, unless you are familiar with home repair I’d advise letting a professional handle it. Sure, it might sound expensive at first. But when you add up the expenses of equipment you’ll need to do all this on your own, it really isn’t much. 

And you also get an expert hand helping you with your issue. Someone who has probably dealt with the same thing a hundred more times. So, don’t take the risk and just hire a professional. 


The foundation is without a doubt the most essential part of a house. Thus, it is critical to ensure that your home’s foundation is free of flaws. By now, you’ve got to know everything about foundation leak repair and other foundation repair methods. 

So, I’m sure you can start working on a fix right away. But, I do advise that you hire a professional and let him take care of your issue. 

Kenneth Wilson
August 23, 2021
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Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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