The required installation depth is a primary factor in determining the total cost of a helical pier because the price is directly tied to the amount of material and labor used.

According to ACN Construction, depth affects the cost in the following ways:

• Increased Material Requirements: Reaching stable bearing strata at deeper levels requires additional steel shaft sections and extra helix plates, which adds to the material cost per pier.
• Additional Labor and Equipment Time: Deeper installations require more time for the hydraulic machinery to screw the piers into the ground, increasing the labor and equipment mobilization costs associated with that specific pier location.
• The Role of Depth Clauses: Most contracts include a depth clause that allows for pricing adjustments if subsurface conditions differ from initial estimates. For example, if a pier originally scoped for 15 feet must reach 25 feet to find stable soil, the total cost will increase proportionally to account for the extra 10 feet of shaft and installation effort.

While the base helical pier cost per pier typically ranges from $1,500 to $3,500, unforeseen soil layers such as unexpected clay or fill can trigger these depth-related cost increases.