Basement Leaks Where The Wall Meets The Floor

Last Updated on June 23, 2021 by Kimberly Crawford

At first glance, basement leaks where the wall meets the floor may look menial or harmless. But when left unchecked, the small leaks might affect the structural integrity of your basement and the overall value of your home.

Aside from this, moisture buildup in the basement caused by leaks encourages the niching of molds, posing health risks for your family. 

With these being said, what can be done when you spot basement leaks where the wall meets the floor? This post will give you a roundup of what you can do, when you should do it and how to avoid it completely. 

Related: Basement Drain Backing Up When Washing Clothes?

why basement leaks where wall meets floor

What is a cove joint?

The cove joint is basically the spot where the basement wall meets the floor. Seepage or small leaks flowing through it is an extremely normal occurrence in the cove joint.

You have to know, however, that cove joint seepage is induced by prolonged heavy rains. This happens when the accumulated water rises to the foundation walls of the home. 

Since the basement is at the lowest ground level, its cove joint is more vulnerable for seepage than the other cove joints of the home. 

Why is there a gap between the basement wall and floor?

basement leaks

A cove joint’s existence is because of the way concrete is poured in the basement walls and floor. Specifically, when the foundation’s footings are already in place, pouring the basement walls immediately comes after.

They pour the basement walls in a keyway (a special board inserted while the concrete is still wet to make a tapered channel by the basement wall) to make sure that all the wall portions are properly aligned. 

After the basement walls have been poured and after they have cured, the basement floors are poured next. The definite point which separates the cured concrete used in the basement walls and basement floors make the cove joint. 

Related: 16+ Different Types Of Flooring With Pictures (Kitchen, Bathroom, Living Room,…)

Finding the sources

Before you could determine the right drain tile system to install and for you to start panicking about basement leaks where the wall meets the floor, you must first know where the seepage is coming from.

There can be a lot of reasons as to why you are experiencing cove joint seepage in the basement and here are the most common ones. 

#1. Raised ground water level

Seepage has a lot to do with what they call as hydrostatic pressure or the rising level of groundwater due to heavy downpour and changing temperatures that may cause soil over moisture. When this happens, the water pressure can cause cracks in concrete. 

#2. Condensation

Speaking of changing temperatures causing over moisture, another natural process that can cause seepage would be water condensation. When the warm and humid air in the basement comes in contact with the cool, insulated foundation walls, condensation or wall perspiration happens. 

The immediate solution to this is dehumidifier. You can test for the level of condensation in the basement wall by taping a foil on the wall and let it sit there for two days. The more droplets present in the foil, the higher the level of condensation. 

#3. Wall cracks

Cracks on the wall could be caused by many reasons too. When the roof gutters are damaged or when the windows are not installed or sealed well, they add moisture to the basement by cascading that water underneath, causing seepage in the cove joint.

#4. Problems in the plumbing

When there are active sources of leaks in the drain pipes or in the plumbing system, expect that it would manifest itself in a lot of areas in the basement including the cove joint.

If the leaks are not that big, locate white, salt-like residues along the cove joint. This is one of the signifiers of plumbing leaks and its effect on foundation walls. 

As have been mentioned, these might not be all when it comes to the sources of cove joint seepage in the basement. The next section will tell you why it merely sealing the cove joints would not fix the seepage. 

Should I seal the cove joint?

Sealing a cove joint is not a good measure to stop seepage. The role of sealants is just to act as a barrier where the first seepage is seen. Because of this, it will encourage water pressure buildup somewhere else along the basement walls. 

Another reason as to why sealing the cove joint is not a sustainable intervention is because it does not last long.

One way or another, if it breaks due to high water pressure, you can expect a one-time-big-time flooding in your basement. As such, you are only adding more problems in the long run. Fortunately, a more permanent fix has been introduced and that would be through a drain tile system. 

How to waterproof the cove joint

When it comes to waterproofing the cove joint, there are two measures that can be employed. The first one is by installing a drain tile system; the interior or the exterior drain tile. The second one is by adding a protective coating to the exterior basement walls. This is called the exterior waterproofing membrane. 

In this section, we will have a brief rundown of these cove joint waterproofing methods. Basic descriptions are highlighted along with their pros, cons, and costs. 

Related: An Ultimate Guide to Waterproofing your Michigan Basement with Ease

#1. Interior Drain Tile

This one is the most common type of waterproofing for cove joint leakage. They can be made of plastic or clay and range from a few inches to just a foot.

It works by relieving the water’s upward pressure through the collection of the water underneath the floor. The collected water is then channeled to what we call as a sump pump. 


  • Easy installation without damaging wall exterior. 
  • Less expensive (both in material and installation costs). 
  • Made of plastic or clay, hence, less vulnerable to wearing due to harsh elements. 


  • Not recommended for finished or fully furnished basements.
  • You cannot use your basement while the installation process is on-going. 
  • Not recommended for stone and brick basement foundations. 


This type of drain tile could be installed within a day. At an average, installation could range from $8000-15000.

#2. Exterior drain tile

This type of waterproofing, on the other hand, works by relieving water pressure from the wall’s exterior. As such, this type of drain tile system requires wall excavation.

Compared to the interior drain tile, this one is more expensive and more costly when it comes to labor and installation. Nonetheless, if you are working on a finished basement, the exterior drain tile could be a part of the finishing touches. 


  • It prevents the saturation of moisture around the foundation walls of the basement, keeping the water away from the walls. 
  • Cost-effective since you can add the exterior waterproofing membrane after you have excavated the exterior wall for the drain tile. 
  • Does not pose damage to the basement interior. 
  • Perfect for finished basements. 


  • Installation can be very messy.
  • Installation cost is pricey. 


This one is more labor intensive due to the need to excavate the walls. In terms of cost, installation ranges from $14000-35000. 

#3. Exterior waterproofing membrane

Most of the time, waterproofing from the interior might not be recommended especially when you are working on a finished basement and porous concrete walls. In these circumstances, you can turn to exterior waterproofing membranes. 

This works by adding a layer of waterproof coating to the foundation wall. The most used one is the PVC waterproofing membrane. Other waterproofing membranes include bituminous membrane, elastomeric membrane, and crystalline waterproofing membrane, among others.

This is done through wall excavation. You can reinforce this by attaching a drainpipe at the trench’s base. This is done to eliminate excess water. 


  • Durable and easy to install. 
  • Vapor permeable and not vulnerable to tearing. 
  • Keeps water out thanks to its reinforcing base. 


  • Requires wall excavation.
  • Not recommended for homes with exterior structures such as garages or decks. 


You will find that this one is a bit pricey so if you are eyeing to coat your exterior walls with one, do it in one wall excavation project. Overall, the cost of an exterior waterproofing membrane is from $55-120 per square feet.

The reason behind this variance is because there are a lot of materials for a waterproofing membrane that you can choose from. 

How long does a drain tile system last?

Drain tiles are essentially built to last. Before more modern drain tile systems emerged, even the clay drain tiles were known to last for at least 20-30 years. With current drain tile systems (interior and exterior drain tile systems), durability is ranged from 20-50 years given good conditions and maintenance. 


As we have succinctly discussed in this post, basement leaks where the wall meets the floor is not at all harmless. It may lead to various structural repercussions. This necessitates applying interventions, specifically a drain tile system.

You can choose with two types of drain tile systems depending on the structure of your basement. A third alternative is also existing which is adding a layer of protective coating called the exterior waterproofing membrane. 

With all things considered, we have to secure the basement walls once we see cove joint seepage. While it is a common occurrence, it cannot be left unchecked. Installation of the drain tile systems can be done on your own. But if you are not sure about how to navigate through this, consult professionals.