How much soil expands is often dependent on the weather. If it is dry, the soil will begin to shrink and settle, bringing part of all of your concrete slabs or foundation down with it. If it is particularly wet, the saturated soil can greatly expand press up against your concrete and foundation with a great amount of force. In both situations, concrete slabs and your foundation could sustain minor cracking and shifting at first. But as these shrink-swell cycles continue, significant damage can result in cracking and uneven concrete as well as bowing walls and a settling foundation. All of which can be safety hazards and result in extensive repairs.