You've had somebody out, maybe two somebodies, and now you're holding paperwork with a word on it you had never heard a month ago. Helical. Push. Resistance. Underpinning. The quotes may not even be for the same thing.
Here's the part that settles most of it. These are not competing brands of the same product. They're two different tools, and the structure sitting on top of the dirt is what picks one.
Push piers and helical piers both carry your house down to ground that will hold. A push pier is driven by hydraulic pressure using the weight of the house as resistance. A helical pier is turned into the ground by a machine's torque. Weight decides which one fits, so heavy houses need driven piers.
One is compression, one is torque
Every pier system in the trade is solving the same sentence: your footing is sitting on soil, the soil moved, so the house moved. Steel has to reach past the soft part and pick up the load. The argument is only about how the steel gets down there.
The owner puts the whole distinction in nine words: "One's based on torque, and one's based on compression."
A push pier gets driven
A push pier is a smooth steel tube. A hydraulic jack presses it down in sections, and the thing it pushes against is your house. When the tube stops going down, it has met ground dense enough to resist the full weight of the structure above it.
That's worth sitting with, because it means the house performed the test itself. The crew reads it on a gauge: "The PSI, basically, is how hard you're pressing into the ground, where it's going to resist enough from the weight of the house to lift, kind of like when you talk to old school, old carjack."
A helical pier gets turned
A helical pier is a shaft with steel plates welded around it like the threads on a screw. A torque motor turns it into the ground until it reaches a specified resistance, and the torque reading is converted to a load rating.
Because the machine supplies the force, the pier doesn't care what the building above weighs. That's a genuine advantage, and it's the reason helicals belong under light structures and under ground that has nothing built on it yet.
The weight above the dirt decides first
This is the whole fork in the road, and it isn't a matter of taste.
A push pier has to have something heavy to push against. A full masonry house on a proper footing supplies that. A sunroom, a deck, a light addition or a freestanding porch often doesn't, and pressing against a structure that light can lift it before the steel reaches anything solid.
Run it the other way and it also holds. Under a settled masonry house that has to come back up, driven steel is what the crews here reach for. In the owner's words: "We offer 3 different types of piers for it, but most of it's gonna be the 90% with our push pier."
What's between your footing and solid ground decides second
Everyone's comparison stops at the structure. In this part of Georgia the dirt deserves a vote too, and this is where a lot of quotes go quiet.
A screw has to turn its way down. A driven tube only has to get through. That difference stops being academic the moment there's something hard and loose in the way, which around here is common, because of how basements get backfilled:
"If there's a trash pit, or if it's backfilled when you got rock, say you got an 8-foot basement, and they start at the bottom, they backfill it 4 feet, and they put all the boulders in there. Well, if you go down with a screw, a helical pier, and you go down 4 foot and you hit that boulder, it's just gonna spin. It won't go through it."
Buried construction debris, old stumps, big roots and boulders do the same thing. That's a fact about ground conditions, not about anybody's installers, and it's the reason the pier choice on a metro Atlanta lot can come down to what the grader buried in 1978.
One more thing about the ground here, since you'll read the opposite everywhere. Georgia red clay is usually blamed for all of this. The USDA rates the clay under most of metro Atlanta as low for shrinking and swelling, so it isn't the villain. What actually undermines a footing here is water: a grade that falls back toward the house, a downspout emptying at a corner, fill that was packed only on top, and a few hard downpours washing a hollow out underneath. Signs of foundation problems walks through how that shows up indoors.
The question almost nobody asks: stabilize or lift?
Pier type gets all the attention. Whether your house goes back up gets almost none, and it's the difference you'll actually see from the driveway.
Stopping the movement and putting the structure back where it was are two different outcomes. A contract that says stabilize means the house stays where it is now, cracks and all. A contract that says lift means the load comes back up. Ask which one you're signing, because the word is usually in there.
There's a related piece of physics worth knowing if your problem is a wall rather than a floor. Piers alone do not bring a bowed or leaned wall back to plumb. Lifting from below without first pushing the wall laterally back into position can make it worse, so on that kind of job the push and the lift happen together. That's the whole story on why chimneys lean.
Here's what the lift feels like when it's happening. One homeowner watching from inside:
"Three push piers were installed under the slab on the garage door side of the house. I was in the kitchen when they were applying hydraulic pressure to the piers--the entire house moved--and I knew we had a winner."
T Schmelt, 5 stars
The third situation: a house that isn't built yet
The comparison changes completely when there's no building to push against.
On a lot with poor soil, a steep cut or deep fill, piers can go in before the footings are poured, so the house starts out sitting on steel instead of settling onto it later. There's no structure to drive against yet, so this is helical territory, and it's the job those augers are built for. Anglin's runs two tractors with auger heads for exactly this work.
Under an existing house, though, the crews here drive steel. Turning a shaft in under a footing that's already loaded can open voids in soil that's already the problem.
What actually sets the price, and what doesn't
Three practical things fall out of all of this.
- The pier type is not the price. How many piers, how deep they have to go, and what each one is carrying set it.
- A pier under a chimney or a center garage column is doing far more work than a typical foundation pier, so it costs more per pier. The steel is heavier for the same reason: "Our pipe, sometimes, though, is a little bit stronger, because we know we're going to get a lot higher PSI to lift it."
- A per-pier price quoted over the phone is a guess at both variables, because nobody knows the depth until they dig.
Real numbers, the job minimum and what's included live on the foundation repair page, along with the pier warranty, which runs for the life of the structure and transfers to whoever buys the house from you.
What to ask about any pier quote
Four questions, and you can ask them on the phone:
- What is the pier being driven or turned to, and how will you know it got there? To bedrock, to refusal, and to torque are three different claims. Any of them can be right. A straight answer means somebody thought about your house.
- Does this contract stabilize or lift? The word will be in the paperwork.
- What happens to the cracked brick afterward, and is it in this price?
- How deep do you expect to go, and what happens if it's deeper? Ask whether depth is included or billed.
Frequently asked questions about push piers and helical piers
Which is better, push piers or helical piers?
Neither, on its own. The structure decides. A heavy masonry house that has settled is the natural candidate for driven push piers, because its own weight is what drives them and confirms they reached solid ground. A porch, a deck, a light addition or a site with nothing built on it yet is helical territory, because a machine supplies the force instead.
Are helical piers stronger than push piers?
They're rated differently rather than ranked. A helical pier's capacity comes from a torque reading taken as it turns, which is an accepted engineering measure. A driven pier's capacity is demonstrated by the weight of your house refusing to push it any further. Both reach load-bearing ground; they just prove it in different ways.
Do push piers have to reach bedrock?
Not always. They go until they meet ground dense enough to resist the full weight of the structure, which in some yards is bedrock and in others is a firm bearing layer well above it. Depth varies house to house and often corner to corner, which is why a pier price quoted before anyone digs is an estimate of the unknown.
Does the pier type change what I pay?
Less than most people expect. The count, the depth and what each pier carries drive the number, so a shallow job needing many piers can cost more than a deep job needing few. One pier under a chimney or a center garage column carries far more load than a typical foundation pier and is priced accordingly. The foundation repair page publishes the real figures.
What is a resistance pier?
It's another name for the same driven steel system. Resistance pier, push pier and driven pier all describe a tube pressed into the ground by hydraulic force until it resists. Helical pier, helical pile and screw pile likewise all describe the turned version. If two quotes use different words, check the mechanism before assuming they're quoting different work.
Can a pier bring my cracked wall back into position?
Lifting a footing brings the structure above it back up, and brick closing back together is normal on that kind of repair. A wall that has bowed or leaned outward is a separate motion, though, and vertical lift alone will not return it to plumb. That one needs lateral pressure applied first and the lift done with it.
Find out which pier your house actually needs
You shouldn't have to referee a debate between two quotes using words nobody explained. Someone can walk the house, look at what moved and how heavy it is, and tell you plainly which system belongs under it and why.
Anglin's has been putting steel under metro Atlanta houses since 1930.
Call 770-422-2924 for a free look.