If you collect three foundation quotes in Northwest Arkansas, there is a good chance you will see both systems recommended for the same house. That is not necessarily dishonesty. It is usually specialisation: a company that owns helical equipment recommends helicals, and a company set up for resistance piers recommends those. Knowing which one the engineering actually favours puts you in a much better position to read the quotes.
Helical piers
A helical pier is a steel shaft with one or more helix plates welded to it, screwed into the ground beside the footing by a hydraulic torque head. As it turns, the installer watches torque. Torque correlates to soil bearing capacity, so the machine is effectively taking a live reading of the ground the whole way down. When torque reaches the design value, the pier is at capacity. A bracket then ties the footing to the shaft and the load transfers.
The consequence worth understanding: helicals produce evidence at every pier, in real time. On the karst geology that runs through Bella Vista and Cave Springs — where competent strata sits at wildly inconsistent depth and clay-filled fractures hide between limestone ledges — that feedback is the whole value. A void shows up as a torque drop the moment it is reached, not as a settled corner two years later.
Helicals also need no help from the building. The torque head supplies the force, so a light frame addition, a deck, or a porch column can be piered just as readily as the main structure. Anything added to a house later tends to be exactly the part that settles first, so this matters more often than it sounds.
Push (resistance) piers
A push pier is driven rather than screwed. Short steel sections are pressed into the ground hydraulically, one after another, using the weight of the structure itself as the reaction load. When the pier stops advancing under maximum pressure, it has found material stiffer than the load above it, and that refusal is the proof of capacity.
This has an elegant logic to it: the pier is tested against the actual load it will carry, by the actual building. It suits heavy structures well — full-masonry and two-storey brick homes where there is plenty of weight to work against and the target strata is deep and reasonably uniform.
The limitation is the same fact viewed from the other side. If the structure is light, it cannot generate enough reaction force to drive the pier to competent material, and the pier reaches apparent refusal early. The other failure mode in our geology is a shallow limestone ledge: the pier stops, pressure spikes, refusal is recorded — and beneath that ledge sits a clay pocket that will keep consolidating.
Side by side
| Factor | Helical piers | Push piers |
|---|---|---|
| How it reaches strata | Screwed down with a hydraulic torque head; installation torque correlates to bearing capacity. | Driven hydraulically in short sections, using the weight of the structure as the reaction load. |
| Proof of capacity | Live torque reading at every pier, as it goes down. | Driving pressure at refusal, verified against the structure's known load. |
| Structure weight needed | None — the machine supplies the force, so light structures are fine. | Substantial. Light or single-storey framing may not generate enough reaction. |
| Typical NWA fit | Most homes, additions, decks, and anything on a lot where depth to strata is inconsistent. | Heavier masonry and full-brick two-storey homes over deeper, more uniform strata. |
| Behaviour in karst | Torque feedback flags a void or a soft pocket immediately, mid-install. | Can hit a shallow ledge and read as refusal before reaching competent material. |
Why the honest answer is often "both"
Houses are rarely uniform. A 1970s ranch with a 2005 sunroom on the back has two different structures sharing one footprint: enough mass at the front to drive resistance piers, not nearly enough at the back. A scope that specifies helicals under the addition and push piers under the main mass is not a contractor hedging — it is a scope that matched the method to the conditions twice.
This is the practical case for scoping from measurement rather than from a walkthrough. Soil sampling and a documented elevation survey tell you depth to competent strata, how consistent it is across the lot, and how much of the structure is actually settling. Those three facts decide the method. Read more about the soil conditions behind NWA foundation movement, or see the full method-by-method breakdown of foundation repair.
What to ask whoever is quoting you
Three questions separate a scoped bid from a product pitch. First: what is the design depth, and what is it based on — soil data, or the last job down the road? Second: how will capacity be verified at each pier, and will I receive those readings? Third: what happens if a pier does not reach design capacity at the expected depth — who absorbs the extra footage?
A contractor who can answer all three without hesitating has engineered your job. One who cannot is selling you their equipment. Either way, what you own afterwards depends on the paperwork: pier logs, a re-survey confirming the correction held, and — where the property qualifies — a transferable warranty bound to the property rather than to the company that installed the steel.