Remember, if you are using a soaker hose a timer will greatly simplify their use. Get the complete Coping With The Joys of Home Ownership FREE with a paid inspection. The heavy clay that causes the most foundation problems contains montmorillonite. When the clay soil is increasing in volume it can exert a force of three to fifteen tons per square foot. Most houses only weigh 350 to 450 pounds per square foot, consequently, the volume change can move a house up and down easily.
Expansive soils can be red, black, gray or even orange.
The important thing to keep in mind is that moisture variations cause this volume change in the soil that many homes are built on. Now lets get back to the subject of maintaining your foundation. Since the moisture content under and around the perimeter of your foundation determines foundation movement, it follows that you should maintain the moisture content as evenly as possible to minimize movement. The same thing happens with a concrete slab foundation, only on a larger scale. When hot, dry weather comes along, some of the moisture will evaporate from the soil around the perimeter of your foundation, causing the soil around the perimeter to dry and shrink away from the foundation.