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Expansive Soil And Foundation Cracks Video

When the soil starts to dry out, the clay soil will contract, creating large cracks in the ground. This can spell big problems for your foundation if you have a shallow foundation on a garage or room addition or if your house is built on a slab. These soil settlement cracks indicate that the soil is extremely dry. This can lead to the cracks in your foundation.

To cure this, the soil down about two feet needs to receive water. The water has to get down to the bottom soil quickly. Use an auger to drill holes 2 feet on center and 2 feet from the house all around the house. This will allow rain or garden hose water to travel down into the soil without getting side tracked by the grass and flowers.

Once the holes are drilled, fill them with grounded small, pea gravel. Fill the hole all the way with the gravel. Use your garden hose to fill the hole with water. You will be amazed at how much water the hole will hold.

These holes and gravel will get the water down into the soil and get it moisture. This reduced the ground shrinkage and helps prevent those foundation cracks.


8 Responses to Expansive Soil And Foundation Cracks Video

  1. Hello Tim,

    I was watching your video on subsidence . Looking at the text which accompanies the video the sentence regarding "garages , room additions or if your house is built on a slab" is confusing. I would think that all modern houses are ultimately built on concrete slabs. Is that not correct?

    Robert Wacker
    Los Angeles, CA.

    • Robert,

      That's not correct. I visit LA frequently and know most of your housing is built on slabs. Come east of the Mississippi River, and you'll discover most houses are built on concrete foundations with basements or crawlspaces under the living area. The floor systems are wood, not concrete like you're used to.

  2. Where can I buy the drill tool you are using? What is called, auger?Home Depot does not seem to carry anything similar in my area. If I don;t have that tool, any recommendation for how to dig those holes? One last question, you recommend digging these holes 2 feet away from the foundation and 2 feet away from each other, i.e. at 2 ft steps, right?

  3. Hello Tim,
    I greatly appreciate your video (heck all your efforts) regarding expansive soils. Your solution is viable and cost effective that most home owners can tackle.

    However, it is not clear to me how the dry soil conditions can lead to foundation cracks. Please explain.

    Paul DiPasquale

    • Paul,

      When the clay soil drys out, it loses volume and shrinks. If the shrinkage is not consistent around/under the entire foundation, it creates vast amounts of tension on the structure. Highly expansive clays like montmorillonite can have an expansion factor of 8 or 10X in volume!

  4. Hi Tim,

    What about areas that abutt the house such as a brick patio and a deck that I cannot crawl under? How do you address those areas?

    • Elizabeth,

      You need to get the holes CLOSE to the foundation for this to work.

      That means the brick patio should have been kept away from the house 18 inches.

      Same with the deck. It's all about thinking ahead and knowing the type of soil you have *before* you build or buy.

  5. Tim I enjoyed your video. If a french drain underneath a swimming pool to catch ground water was backfilled with gravel and this clay and then topped with dirt for vegetation, does the clay being there still present the same problem? I am noticing that the ground continues to sink around the french drain. Thanks!!

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