French Drains or sub drains are commonly installed near the perimeter of a building at the lowest point where standing or ground water is found. The system may terminate at a point where the water will not drain back towards the house. Depending on the situation and site conditions sometimes a gravity system may not work the installation of a sump pump may be needed to get the water flow away from the house.
Due to the poor material and construction techniques older homes are more vulnerable to the effects of water weather and aging. Many homes are built on clay soil. Clay soil shift seasonally as the ground becomes wetter in the winter and drier in the summer expansion and contraction of the soil cause the foundation to move and rotate. Moisture can seep under the foundation causing lifting and supplemental of the foundation. Furthermore uncompacted soil can settle over time as moisture causes the soil to compact.