How deep do Helical Piers need to go?
A. Helical Piers need a minimum of 5 feet of soil above the top helix and need to be deeper than the active zone of soil, which is the zone of seasonal wetting and drying. Also, the Helical Pier needs to achieve the torque (turning or twisting force) specified on the plan of repair. Torque will vary based upon depth and density of the soil.