Foundation Movement

Shallow soil is generally the most affected by seasonal moisture
changes. If the load bearing soil consists of expansive clays which are
subjected to changes in moisture content, differential foundation
movement can occur if it does not happen uniformly throughout the entire
slab.
This differential movement can result in “dishing” or “doming” of
the foundation, and can become quite pronounced, especially in areas
where the local climatic conditions include extended seasonal periods of
both hot, dry weather and cooler, wetter weather (Just like ours!). In either
case (consolidation or differential shrinking/swelling movement), poor
design and/or construction can result in unacceptable performance.