Mapping the foundation of a home is a powerful way of documenting the exact state of the ground floor of a property on a specific date. Houston area soil is highly expansive and the drought that we have experienced the better part of 2011 has constricted soil bases significantly. This greatly affects the ability of soil to support weight (or in technical terms: the load of your home). When the soil has become so dry that it has constricted to the point of detaching from the side of a home by an inch or more, moisture evaporation of the soil under the home is occurring. This evaporation is changing the ability of the soil to support the perimeter of the house as compared to the soil further underneath the foundation. When the load on the foundation is supported differently in the center than it is along the edges issues are going to arise. It is just a matter of time.