What Are Helical Deck Piers?
A sinking or uneven deck is more than a cosmetic problem. Unlevel decking creates trip hazards, stresses ledger connections, and can compromise the structural tie between the deck and the house. In Alabama's climate, where expansive clay soils dry and shrink in summer and heavy rains saturate the ground in spring, deck footings placed in shallow soil frequently settle over time. APS Foundation Repair and Waterproofing installs helical deck piers that are specifically sized and designed for the loads imposed by residential decks, screened porches, sunrooms, pergolas, and other light attached or freestanding structures. Helical piers are installed by rotating the steel shaft into the ground without excavation, advancing the helical plates through surface soils until the assembly reaches bearing capacity in stable soil below the zone of seasonal movement. The result is a foundation point that will not heave with frost, compress with surface loading, or wash away in heavy rain events, all of which are real concerns in Alabama's geology and weather patterns.
How Helical Deck Piers Work
A helical deck pier consists of a central steel shaft with one or more helical plates welded at engineered intervals. An APS installer uses a hydraulic torque motor to rotate the pier into the ground, with helical plates advancing much like a screw through soil. Installation torque is continuously monitored as a proxy for bearing capacity, when torque reaches the design threshold, the pier has reached stable bearing soil. A steel bracket is then attached to the top of the shaft and positioned beneath the existing deck beam or post base, allowing the structure to be lifted, leveled, and stabilized. For new deck construction, the process is the same, but piers are installed before framing begins, providing a permanent, engineered footing that eliminates the settlement risk of shallow concrete footings.
“Deck footing failures are one of the most preventable problems we see. Concrete tube footings poured in disturbed or fill soil are almost guaranteed to settle. Helical piers install to actual bearing capacity, there is no guesswork, and the torque numbers tell us exactly when we have reached stable ground.”
How APS Installs Helical Deck Piers
- 1
Assessment and Load Calculation
An APS specialist reviews the deck or porch structure, estimates tributary loads, evaluates existing footings and post conditions, and determines appropriate pier diameter, helix configuration, and spacing.
- 2
Equipment Positioning
APS uses compact hydraulic torque motors that fit under existing deck framing without requiring the deck to be demolished. Access requirements are reviewed during the assessment stage.
- 3
Helical Pier Installation
The helical pier is rotated into the ground at each footing location. Extension sections are added as needed until the pier reaches bearing soil, confirmed by installation torque readings.
- 4
Bracket Attachment
A steel cap bracket is secured to the top of each installed pier. The bracket is sized for the deck beam or post bearing on it and is hot-dip galvanized for corrosion resistance.
- 5
Leveling and Load Transfer
Hydraulic jacks are used to lift settled sections of the deck structure to restore level, then loads are transferred to the new pier brackets. For new construction, framing proceeds directly onto the installed brackets.
- 6
Final Inspection and Cleanup
The completed installation is reviewed for level, bracket engagement, and overall condition. The work area is cleaned of soil spoils and equipment, and the deck is returned to service.
What Helical Deck Piers Cost and What Is Covered
Cost Range
$600 to $1,500 per pier
Warranty
Manufacturer warranty on helical pier components plus APS in-house workmanship warranty, transferable to subsequent homeowners
Frequently Asked Questions
Can helical piers be installed under an existing deck without tearing it apart?
In most cases, yes. APS uses compact equipment specifically selected for low-clearance work under deck framing. Whether full access under the deck is possible depends on the deck height and framing configuration, which we evaluate during the assessment.
How long does helical deck pier installation take?
A typical residential deck with four to eight pier locations is usually completed in a single day. Larger porches or sunrooms with more pier points may take two days.
Will helical deck piers work if my soil is mostly clay?
Yes. Helical piers are well suited for clay soils because the installation extends below the active zone where clay expands and contracts with moisture changes. The stable bearing layer below this zone is where the helical plates engage.
Can I use helical piers for a new deck I am building?
Absolutely. Many homeowners and contractors choose helical piers for new deck construction because they provide an engineered footing installed to bearing capacity rather than relying on a concrete tube footing that may be placed in fill or unstable soil. APS can coordinate with your deck contractor on timing.
What happens to the old concrete footings when you install helical piers?
In most cases, the existing failed footings are simply bypassed. The helical pier bracket positions the new support independently of the old footing. Removing the old concrete is optional and depends on site conditions.