A drain tile system ensures that excess water can’t build up in the soil around the foundation. If there’s no excess water, there’s no hydrostatic pressure. Here’s how an exterior drain tile system works:
The foundation is excavated down to the level of the footer, and a sump pit is dug.
A shallow trench is dug around the foundation and then lined with gravel.
A perforated drainage pipe is placed into the trench and then covered with more gravel.
The excavated dirt is replaced.
Any excess moisture in the soil will flow into the drain pipe and get channeled into the sump pit. When the sump pit fills with water, a sump pump expels it away from the foundation.