Foundation on expansive soil Texas is the state where one would most likely wish for a foundation on an expansive soil base. For years, homeowners in the Dallas-Fort Worth Metroplex had to deal with drainage problems that resulted from clay-rich soil that rose above their retaining walls. In some areas of the Metroplex, impervious clay soil drainage was a significant problem. The problem was not getting drainage away from the foundation onto the home’s interior. The first step to solving…