Helical Piers and Push Piers Compared

The principle behind both systems is identical and pleasingly simple. The soil directly under the footing has stopped carrying its share of the building, so the load is transferred onto steel that reaches past that soil to a layer capable of carrying it. Everything else is detail, but the detail decides which system your house should get.

Push piers: driven, and proved by pressure

A push pier is a plain galvanised steel tube advanced into the ground hydraulically, in sections, from a bracket fixed to the footing. The reaction mass, the thing the hydraulic ram pushes against, is the weight of the house itself. The pier advances until it will advance no further under the available force, a condition called refusal, which is taken to indicate it has reached competent bearing.

That gives push piers a defining characteristic: they need a heavy enough structure to drive against. A two-storey masonry house provides plenty of reaction mass. A light single-storey timber-framed addition, a porch, or a stoop does not, and attempting to push against one simply lifts it rather than advancing the pier.

Capacity is documented by logging the driving pressure at refusal for each pier. A good installation produces a pier-by-pier record of that pressure and the depth reached.

Helical piers: screwed, and proved by torque

A helical pier is a steel shaft with one or more helical bearing plates welded to it, screwed into the ground like an auger by a hydraulic torque motor. Capacity comes from the bearing plates pressing against the soil rather than from end refusal, and the installation torque required to keep turning the shaft correlates with the capacity being achieved. Installers drive to a target torque, and that torque reading is the proof.

Because capacity is generated by torque rather than by the building's weight, helical piers work under light structures. Additions, porches, stoops, chimneys, and single-storey extensions are all natural helical applications. They are also used for new construction and for supporting equipment, which push piers cannot do at all since there is nothing yet to push against.

Choosing between them

	Push pier	Helical pier
Capacity comes from	End bearing at refusal	Helical plates bearing in soil
Proved by	Driving pressure at refusal	Installation torque
Needs building weight	Yes, as reaction mass	No
Best suited to	Heavier, multi-storey, masonry structures	Lighter structures, additions, porches, new work
Typical depth behaviour	Goes to refusal, depth not chosen	Driven to target torque, more controllable
Installed cost here	$1,400 to $2,600 per pier, depth dependent

On a large share of jobs either system would work, and the choice comes down to the soil profile and the installer's judgement and equipment. What should not happen is a contractor offering only one system because it is the only one they own, without explaining why it fits your house.

Depth, which is where the money is

Pier count is set by how much footing has lost support. Depth is set by geology, and around Tallahassee geology varies more than in most markets.

North of the Cody Scarp, in the Red Hills, soils are deep sandy clay and competent bearing may sit well down, so piers run long. South of the scarp, in the Woodville Karst Plain, Suwannee limestone sits close to the surface under thin sand, and refusal can come much shallower. Same repair, same house, materially different price.

Karst adds a second complication: because limestone surfaces dissolve unevenly, adjacent piers along the same footing can hit refusal at quite different depths. A pier schedule that assumes a uniform depth across a wall will be wrong somewhere on that wall. This is exactly why a quote in this market should state pier count, state assumed depth, and say what happens to the price if actual depth exceeds the assumption.

Lifting, and how much to ask for

Once piers are installed and brackets are set, the crew can attempt to recover elevation by jacking the footing back up. How much is recoverable depends on how long the movement went on and how the structure has adjusted around it.

A house out of level for twenty years has plumbing, tile, brick veneer, and finishes that have all settled into its current shape. Forcing it hard back to a flat plane can crack all of them, and occasionally does more damage than the settlement did. The professional approach is to stabilise first so movement stops, then recover as much as the structure accepts without new damage, watching crack behaviour through the lift. A contractor who states a realistic recovery in inches before starting is describing the job accurately; one who promises level is selling.

Two warranties, not one

Steel pier systems from established manufacturers carry a product warranty on the pier itself, commonly written as a lifetime warranty and typically transferable to a subsequent owner of the property. That transferability is genuinely valuable at resale.

Separately, the installing contractor carries a workmanship warranty covering the installation, which is generally shorter. The two cover different failures and it is worth knowing which is which before assuming one document covers everything. Both belong in the written quote.

What the finished job should leave you with

• A pier log: location, depth reached, and the pressure or torque recorded at each one.
• The permit record and inspection sign-off.
• Both warranty documents.
• Excavations backfilled and compacted, not simply refilled.
• A clear statement of what elevation was recovered, and what was not.

That paperwork is what a buyer's inspector will ask for in ten years, and it is the difference between a repaired house and a house with a history. Keep it somewhere findable.