How a helical pier works
A helical pier is a square or round steel shaft with one to four steel plates welded near its tip, each plate formed into a shallow spiral. Hydraulic equipment turns the shaft, and the plates pull it into the ground the way a wood screw pulls itself into a board. Every additional length of shaft bolts onto the last, so the pier grows downward in sections until the plates are bearing in soil dense enough to carry the load assigned to that pier.
Once the shaft reaches that soil, a steel bracket is fitted around the underside of your footing and connected to the pier head. From that moment the load path changes: the weight resting on that stretch of footing travels through the bracket, down the shaft, and onto the helix plates bearing in competent soil. The soil directly under the footing — the soil that moved and started your problem — stops carrying the house there.
The distinguishing feature is what the machine pushes against. A helical pier is driven by rotation, supplied by a hydraulic torque motor mounted on an excavator or a handheld unit in a crawl space. The building above plays no part in the installation, which is why helical piers can be installed under a deck, alongside a new addition, or on a lot with no structure on it yet.
Torque is the quality record — ask for it
Here is the part worth understanding before a contractor explains it to you, because it is the closest thing this industry has to a measurable result. There is a well-established relationship between the torque needed to turn a helical pier and the load that pier can carry: roughly, capacity equals installation torque multiplied by a capacity factor specific to the shaft size. A crew installing helical piers reads torque continuously and stops advancing when the reading corresponds to the design load the engineer specified.
That is why depth is an outcome rather than a target. A helical pier on your house might stop at 12 feet while the one 7 feet away goes to 24, because the soil profile changed. Both are correct if both hit the torque figure. Common depths run 10 – 30 feet, and piers exceeding 50 feet appear where competent strata sit deep.
Ask for the torque log — a sheet listing each pier, its final depth and its final torque reading. A crew that installed correctly has it, because they recorded it as they worked. Keep it with your closing documents; it is the evidence a future buyer's inspector will want to see, and it costs you nothing to request.
When helical piers are the right pick
Helical piers earn their price premium in situations where the building weight is too small to drive a pier by reaction. That covers more homes than people expect: single-story houses, homes with light wood framing, homes over crawl spaces, porches, sunrooms, garages, and detached structures. It also covers everything installed before the structure exists — new construction foundations, room additions, deck footings and light commercial pads.
The second scenario is immediate loading. A helical pier reaches its design capacity the moment it is torqued in, so a builder can pour on it the same week. Push piers need the house to already be there.
The third is access. The torque head can be small enough to work inside a crawl space or in a side yard a mini-excavator would struggle to enter, so tight urban lots sometimes point to helical for purely practical reasons.
Where helical loses on the numbers is a heavy two-story masonry house on deep, weak soil. There, the house weight is an asset — it drives a push pier to genuine refusal for $1,250 – $2,400 per pier instead of $1,400 – $3,100. Both systems are engineered products with long track records; the right one is decided by your structure and your soil, and a bid that offers only one system deserves the question of why.
What helical piers cost
| Line item | Typical range | Unit | What drives it |
|---|---|---|---|
| Helical pier, installed | $1,400 – $3,100 | per pier | Depth, torque required, access to the footing |
| Push pier, installed | $1,250 – $2,400 | per pier | The alternative where house weight is available |
| Concrete pressed piling | $900 – $1,700 | per pier | Shallower, regional, lower cost per unit |
| Settled corner | $5,000 – $14,000 | 4 – 6 piers | Piers set 6 – 8 ft apart along the footing |
| One full side of a house | $10,000 – $30,000 | 8 – 12 piers | Differential settlement along one wall |
| Full perimeter | $25,000 – $60,000 | 20+ piers | Whole-footprint movement, rare |
| Structural engineer’s report | $450 – $600 | per visit | Sets the pier count independently |
| Permit | $75 – $400 | per job | Municipality; sometimes bundled into the bid |
Source: Compiled from published 2025–2026 national contractor pricing datasets and regional underpinning bid data, normalized to installed cost including labor, brackets and equipment. · Last reviewed July 30, 2026 · Reference data · How we compile these figures
The per-pier figure is the easy number. The number that actually sets your bill is the pier count, and it moves with spacing. Piers go 6 – 8 feet apart along the affected footing, so a 40-foot wall is either six piers or seven, and on a job at $2,200 per pier that judgment call is worth several thousand dollars. Two honest contractors can land in different places on it.
This is the reason an independent structural engineer, $450 – $600 for a report, pays for itself on anything priced above roughly $5,000. The engineer specifies the pier count and locations without selling the piers, and their scope turns three bids into three prices for one defined job. A free contractor inspection is a sales visit — often a competent one, though the incentive points toward more piers rather than fewer.
Two line items belong in every bid you compare: whether the engineering is included, and whether restoration of sod, plantings and any cut concrete is in scope. Those two omissions explain most of the gap when one bid looks remarkably cheap.
What installation day looks like
Exterior work starts with a pit at each pier location, roughly 3 – 4 feet deep and wide enough to expose the underside of the footing. The torque head goes on the shaft, the pier turns down in sections, and the crew reads torque as it goes. When the reading is reached, the bracket is set and the load is transferred, sometimes with a controlled lift at that point. Pits are backfilled at the end of each pier or at the end of the job.
A typical residential underpinning job takes 3 – 7 days on site, driven mostly by pier count and access. Add 1 – 3 weeks upfront for the engineer's report and the permit; that lead time is what people forget when they plan around a repair. Homeowners rarely need to move out — the work happens outside the walls, your yard along the excavation line takes the damage, and the house stays livable.
Checking a helical pier recommendation
Four questions cover most of it. What torque figure are you installing to, and where did it come from? How many piers, at what spacing, and who set that number? What caused the settlement, and what is being done about the drainage or the plumbing leak behind it? And does the warranty transfer to a future owner, with what excluded?
On that third question: piers reach stable soil and stay there, so the structural fix is durable. What piers leave untouched is the water that moved the soil in the first place. Where a downspout discharges against the footing or a supply line is leaking under the slab, the unpiered sections of your foundation remain exposed to the same force. Fixing grading and gutters is usually a few hundred dollars and belongs in the same project.
It is also worth confirming that piers are the right category of repair at all. Cracking with no measurable movement, no sloping floors and no sticking doors is often a sealing job, not an underpinning job. Marking crack ends with a pencil and a date, then re-checking across a full wet-and-dry season, is free and is the single largest money-saver available to you.
Related pages
- Push piers — the driven alternative, and when the house weight makes it the better buy.
- Steel vs concrete piers — why depth decides this in expansive clay.
- Types of foundation repair — the full method map, from injection to underpinning.
- How foundation repair works — the seven stages and where the money goes.
- Cost calculator — size a pier project before anyone quotes you.