Some foundation cracks can be very minor as others may be major. It was located directly under a main floor beam and went down to the footing. We injected it with polyurethane and stabilized with steel plates anchored in the foundation. In this way the movement of the foundation is stopped and no infiltration of water can resurvey. We inspected the French drain with a camera to make sure it works properly. This crack was therefore caused by the natural movement of the soil.