Mold growth is a major problem, which thousands of people are experiencing due to a number of factors. Mold takes root partly due to poor workmanship, a limited understanding of the dynamics of water and water vapor movement, and lack of adequate training for builders. Toxic mold concerns rarely happened in old homes. Stopping black mold and other mold types before they begin can be done, but your builder must be well versed in how to keep water at bay with modern building materials and proper construction.