What Are Helical Piers?
Helical piers are steel shafts with helical plates that are advanced into the ground by hydraulic torque motor, similar to a giant screw. Unlike driven push piers that rely on reaching bedrock, helical piers develop their load capacity through friction and bearing across the helix plates, with installation torque serving as a direct indicator of capacity achieved. APS Foundation has been installing helical pier systems across Alabama since 1977, and they are particularly well suited for Huntsville's karst geology, light structures, additions, porches, decks, and situations where driven piers cannot reach stable bearing.
How Helical Piers Work
Helical piers are advanced into the ground using a hydraulic torque motor mounted to an excavator or skid steer. As the helix plates rotate into the soil, the pier gains depth section by section. Because load capacity is directly correlated with installation torque, our crew monitors torque readings continuously and stops when the target capacity is reached, with no bedrock required. This torque-monitoring approach makes helical piers the preferred solution in Huntsville's karst limestone terrain. In karst areas, bedrock can be fractured, contain voids, or appear at wildly inconsistent depths. Helical piers bypass these uncertainties by developing capacity in competent soil above or between fracture zones, with real-time torque data confirming that the required load has been achieved. Helical piers are also the standard choice for light structures, additions, porches, and decks where the load is relatively modest and driven piers may not be practical. Their installation is less disruptive than excavation-heavy alternatives, and they can be installed in confined spaces where large equipment cannot operate. Once the required torque and depth are achieved, a bracket is installed at the top of the pier assembly, attached to the existing footing, and the structure's load is transferred to the pier. A synchronized lift is then attempted in the same manner as push pier installation.
“In Huntsville's karst country, torque monitoring is everything. We are not guessing at bedrock depth. The torque reading tells us in real time when we have reached the capacity the engineer specified. That is a level of confidence you just cannot get with driven piers in fractured limestone.”
How APS Installs Helical Piers
- 1
Free On-Site Assessment
An APS Foundation inspector evaluates the settlement, soil conditions, and structure type to confirm helical piers are the right solution. Huntsville homeowners especially benefit from this assessment given the area's karst geology.
- 2
Small Excavation at Footing
Compact excavations are made at each pier location to access the footing. These are typically much smaller than those required for driven pier installation.
- 3
Torque-Monitored Advancement
A hydraulic torque motor drives the helical pier into the ground section by section. Torque is monitored continuously; installation stops when the torque reading confirms the target load capacity has been achieved.
- 4
Bracket Installation
A load-transfer bracket is installed at the top of the pier assembly and attached to the existing footing, connecting the structure's weight to the stable pier system.
- 5
Synchronized Lift
Hydraulic jacks are synchronized across all pier brackets for a controlled, uniform lift. Where conditions allow, settled areas of the foundation are raised toward original elevation.
- 6
Lock-Off and Backfill
Piers are locked at the lift position, excavations are backfilled and compacted, and a warranty package documenting torque readings and installation depth is provided.
What Helical Piers Cost and What Is Covered
Cost Range
$1,800 to $4,000 per pier; cost varies with depth required to reach target torque.
Warranty
Manufacturer warranty plus APS in-house warranty, transferable to new owners at no additional cost.
Frequently Asked Questions
Why are helical piers better than push piers for Huntsville?
Huntsville sits on karst limestone geology where bedrock is often fractured, cavernous, or at inconsistent depths. Push piers depend on reaching solid bedrock. Helical piers develop load capacity through soil friction and helix bearing, with torque monitoring providing real-time confirmation of capacity achieved. This makes them far more reliable in karst terrain where bedrock cannot be trusted as a uniform bearing surface.
Can helical piers support a full house foundation?
Yes. Helical piers are engineered for specific load requirements, and multiple helix plates can be configured on each pier to achieve the necessary capacity. They are used on both light structures and full residential foundations depending on the soil conditions and pier configuration selected.
How do I know the helical pier has reached adequate capacity?
Installation torque is the direct measure of load capacity for helical piers. Our torque motors record readings continuously, and our crew stops advancement when the torque reading confirms the engineered target capacity. This is documented and included in your warranty package.
Are helical piers suitable for new additions or decks?
Yes, helical piers are frequently used for new construction where deep foundations are needed for additions, porches, decks, or other light structures. They can be installed in confined spaces and do not require the heavy driving equipment used for push piers.