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Clay Bowl Effect

This natural process occurs after soil is dug out during construction and then used to backfill around the foundation with the same soil. No matter how hard the soil is packed, the backfill soil is looser and fluffier than the untouched soil around it. This creates an artificial water table around your home where water will be collected.

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The Clay Bowl Effect Understood

Loose soil around your home’s perimeter may not seem like much of a problem during construction until the rains start falling. That’s when foundation problems start. The foundation starts leaking and water infiltrates the basement.  

While many things can instigate these problems, the clay bowl effect is a common culprit. Here, we will explain this concept and show you how it affects your home. 

What Is The Clay Bowl Effect? 

Typically, construction starts with ground excavation to make room for the foundation and basement or crawl space. Once the foundation is built, a concrete floor is poured. Some of the soil that’s been dug out is then used to fill the space around the edge of your foundation and basement or crawl space walls.  

The backfill soil is mostly loose and fluffy while the untouched soil close to it remains firm and stable. Anytime it rains, the backfill soil will absorb more water than the dense, hard-packed soil nearby. This creates a “clay bowl” around your home, one that holds water exactly where it’s not supposed to.  

If you notice one or more of these signs, you’re likely experiencing the clay bowl effect:  

  • Foundation cracks that leak water  
  • Higher relative humidity in the basement or crawl space than other sections of your home  
  • Persistent mold problems  
  • Puddles on the basement floor  
  • Dark spots on your basement walls/floors 

Should You Worry About the Clay Bowl Effect?  

Wet, leaking wall

The clay bowl effect should be taken seriously since it can lead to basement leaks, water damage, mold growth, and other issues. Anytime it rains, the snow melts, or the water pools around your home for some other reason, your home will suffer. The water will saturate the soil around your foundation, causing it to expand and press against your foundation walls. 

 Because of hydrostatic pressure, water will eventually break into your basement through the paths of least resistance such as cracks in the wall and openings around pipes. The water can also enter the basement through the porous concrete or the floor joint. Hydrostatic pressure can also weaken the joints in the foundation walls and widen the existing cracks.   

Another type of damage the clay bowl effect can cause is bowing foundation walls. Since the backfill soil is not as dense as it used to be, it moves freely, therefore exerting stress on your foundation walls. The constant variations in the pressure can cause the basement walls to bow and become far less stable. 

Possible Foundation Repair Solutions  

As explained, the clay bowl effect can lead to all kinds of problems and eventually even compromises the structural stability of the house. Luckily, there are several methods that can help you resolve this issue.  

Interior Drainage System  

The main problem with the clay bowl effect is that water can damage your foundation and enter your basement. With an interior drainage system that skilled contractors can install along the interior footer of your foundation, you can prevent water from causing trouble. The drainage system will collect the excess water and direct it to the sump pump, from where it will be pumped out of and away from your home.    

Wall Anchors  

Wall anchors prevent the walls from bowing any further and over time can even move them back toward their original position. They are constructed of galvanized steel and are the most effective method for even severely distressed basement walls. They are installed into the stable soil away from the foundation walls.  

Professional Foundation Waterproofing  

The best way to stop the outside water from seeping into your home is to waterproof the foundation. Talk to your local foundation contractor about the best waterproofing solutions for your home.  

Groundworks offer various types of waterproofing solutions to homeowners. Schedule a free inspection and our experts will provide you with a no-obligation quote. With Groundworks, you’ll find a lasting solution, backed with a long-term warranty, that completely suits your needs. 

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