Foundation Movement – Part II

29 Jan

As discussed in the last blog post, foundation movement is usually related to soil movement. The highly plastic clay soils in portions of Texas have caused 100’s of millions of dollars of damage to foundations. In non technical terms, a highly plastic clay is one which expands a lot with an increase in the soil moisture content and then shrinks a lot when it dries. It has been my experience that the worst foundation movement occurs during dry weather, which occurs every summer in north Texas. This dry weather causes the soils to shrink and allows many slab foundations to settle. Fortunately, settlement of a foundation can usually be remedied by installing piers (piers are expensive but are usually very effective in stopping further settlement in the area of the piers).

However, depending on the soil conditions, the opposite can occur when the soils become re-hydrated (either from Mother Nature or homeowner irrigation) and the foundations are heaved upward by the swelling clays. Upheaval can be very difficult to remedy. I have seen some residential slab foundations in Irving and Carrollton (Texas) heave upward 8 to 10 inches and a commercial building slab heave over 12”. Needless to say, this can be catastrophic to the structure. This type of movement creates significant sheetrock cracks, slab cracks, brick cracks, out of level doors and floors, etc. and obviously lowers the value (and livability) of a home and usability of an office building. Foundation upheaval can be a very difficult and expensive problem to remedy.

 My next post will discuss an actual case file where a custom home with a well designed slab foundation experienced about 5” of upheaval during the first year.

For more information on foundation movement, visit


Posted by on January 29, 2011 in foundation repair


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3 responses to “Foundation Movement – Part II

  1. Dan Hegarty

    August 31, 2011 at 8:11 pm

    I have foundation damage. I know I need foundation repair. My question is it better to have the repair done during this drought period or should I wait until the soil is re-hydrated?

    • Jim

      September 9, 2011 at 7:11 am

      Generally speaking, if a foundation moves (settles) because of desiccation of the soils, it is ok to go ahead and install piers anytime. There may be some instances for an exception, but I cannot think of any at this time.

    • Jim

      October 20, 2011 at 4:00 pm

      if the foundation movement was caused by settlement (as opposed to upheaval), then you can repair it at any time of the year.


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