What Are Helical Piles?

Helical piles, also known as screw piles, are a type of end-bearing deep foundation that's comprised of a steel shaft with one (or more) helical-shaped plates attached to it. These "helix plates" allow the pile to smoothly advance through the soil and anchor into stable layers.
This unique design results in an installation process that's both straightforward and efficient. Using a hydraulically-powered gear motor, we rotate the piles into the ground until they reach load-bearing strata. It allows helical piles to be installed quickly with minimal disruption to the site.
You can find helical piles being used across America for everything from small residential projects to large-scale industrial jobs. Their ability to handle significant load capacities and adapt to a wide range of soil conditions has made them a strong alternative to typical poured concrete or driven piles.
But, where exactly do helical piles come from? Are they some new-fangled invention cooked up in the last few decades? Actually, no! The history of helical foundations goes back a lot further than you may realize...

Brief History of Helical Piles

Helical piles have a surprisingly long and storied history, dating all the way back to the 1830's when they were first invented. The original intention was to create a foundation that could handle the soft and challenging soils found in coastal regions and in waterways.
(In fact, the primary use-cases for early helical piles was to support things like lighthouses, piers, and bridges.)
Their relative ease of installation, at least compared to other options of the day, and high load capacities made them a quick favorite among engineers of the 19th century. However, their use declined somewhat in the late 19th and early 20th centuries due to limitations in installation equipment which made it tough to harness their full potential.
In recent decades, advancements in efficient high-torque hydraulic gear motors have revitalized helical pile technology and brought them back to the construction world. Today, they're installed using common equipment like excavators and skid steers, which has improved their practicality for modern projects.
Speaking of modern projects, the applications for helical piles today goes far beyond their historical uses. You'll find them supporting residential builds, commercial structures, industrial facilities, and infrastructure projects of all sizes.
With nearly two centuries of proven performance, this "old" technology is only becoming more relevant with each passing day.

How Does a Helical Pile Work?

Helical piles are a type of end-bearing deep foundation system, transferring structural loads through the shaft and into the helix plates. These plates are embedded in firm soil layers, anchoring the pile and preventing movement under compression or tension.
Helical piles can be installed in a couple different ways: either as "floating" piles, or sunk all the way to bedrock.

Whether a pile actually needs to be installed to bedrock or not depends on factors like the structure’s weight, engineering specifications, and soil conditions.

This is one of the aspects that makes helical piles a unique foundation - they don’t need to reach bedrock to support heavy loads. Because the helix plate(s) provides a large surface area, they can enhance bearing capacity even in weak soils.

How is a Helical Pile Installed?

The installation process is one of the big things that sets a helical pile foundation apart from other solution - and why there's a growing interest in the technology.

Installing a deep concrete foundation typically involves excavating/drilling holes, assembling formwork and rebar, and removing large amounts of spoils. And while driven piles don’t require excavation, they do rely on heavy machinery and can produce significant vibrations.

Helical piles, on the other hand, are installed by rotating the pile into the ground at a few revolutions per minute with a high-torque gear motot. The helix plates along the shaft allow the pile to penetrate the soil and advance with minimal disturbance to surrounding material.

In essence, the process looks like this:

The specific configuration of a helical pile is flexible and depends on its application. Shaft and helix plate sizes can be customized to handle different soil conditions and load requirements. In some instances, more than one helix plate may be used to increase capacity.

Helical piles are available as bare steel material, or with a galvanized coating that enhances durability in harsh environments. This choice, again, depends on your specific requirements and conditions.

What all that means is helical piles are a quick and minimally-invasive deep foundation that can be tweaked to suit your exact needs. Their versatile nature makes it easy to overcome challenging soil conditions or install them in close proximity to existing structures.

But, how does a helical pile actually compare to a concrete foundation? And is one of them a better option than the other?

Helical Piles vs. Concrete Foundations: 5 Key Comparisons

Okay, so now that we're familiar with what helical piles are and how they work, the big question is... how do they stack-up against a concrete foundation?
First, it's worth noting that the choice between helical piles or concrete depends on your specific needs. There's a whole range of factors that help determine the right foundation for a given project, and no two are ever alike. That means a blog post like this one can't ultimately tell you which solution is best for you!
However, what we can do is compare helical piles and concrete on some key points. This will help you understand the strengths and weaknesses of each technology, so you can be better informed about your options.

1. Speed of Installation

Time is big money on a construction project, and every bit you can save puts money back into your pocket. Plus, if you're a contractor, finishing projects faster allows you to get more work done in a season.

2: Land Disturbance

Generally speaking, if you want to put something (like a deep foundation) into the ground, you'll have to take material out. Helical piles buck this trend, as they don't need to be excavated or drilled.

3. Load Capacity

Both options are able to hold significant structural loads. However, there's certain conditions that can present a challenge for concrete. For example, weak or saturated soils can impact installation and performance. On the other hand, concrete can be an affordable choice in good soil conditions.

4. Longevity

A quality concrete foundation should be able to last for many decades, but it is tough to beat the lifespan of a steel helical pile. Especially if your facing a tough environment like high water tables or soil that's prone to movement.

5. Cost

While the cost of a foundation shouldn't be the primary deciding factor, it certainly is one of them. This is an area where a concrete foundation can definitely have an edge, but that also depends on how you look at (and calculate) costs...

Can You Use Helical Piles and Concrete Together?

You know, it doesn't have to be an "either or" scenario when choosing between helical piles or concrete. In fact, they can actually be used together.

Think about structural elements like slabs, grade beams, basements, crawl spaces, or even ICF blocks. These often require, or would at least be improved by, having a deep support underneath them.
Which is exactly where helical piles come in!

Helical piles can be used to support concrete structures, providing a deep foundation that prevents shifting or cracking while increasing longevity.

Basically, you're allowing each technology to focus on what it does best. Concrete is a versatile building material that's great for all types of structures, but doesn't always excel as a deep foundation.
Helical piles, conversely, perform strongly as a deep foundation and will readily adapt to supporting concrete structures.

Using them together combines the advantages of both systems, leading to a stronger and longer-lasting end result.

7 Major Benefits of Helical Pile Foundations

Frequently Asked Questions About Helical Pile Foundations vs. Concrete

Conclusion

When it comes down to it, the "debate" between helical piles and concrete foundations isn’t about choosing which is a better or worse option. It’s about finding the right foundation for your specific project.
Concrete has long been a trusted solution, especially here in Central New York, and it's not hard to see why. It's well-known, relatively affordable, and for a lot of builders is their default solution. That isn't a bad thing, but it also doesn't mean there's no room for another option.
Whether you should use concrete or helical piles for your project depends on things like the type of structure, site conditions, soil properties, and environmental considerations (to name a few). By assessing these factors, you'll be able to pin-down which option is going to deliver the most robust and effective support for whatever it is you're building.
This is where a reliable foundation contractor comes in - and where we have to give our company a little plug.
At CDP Excavating, we're ready to help you determine which foundation best suits your unique conditions. Because even though we're big fans of helical piles, our priority is ensuring you get the right support.
So, if you're curious to know more about helical piles and see if they could be your answer for a sturdy support, reach out to us today. If helical piles are the right option, we'll be happy to recommend them. And if they aren't well-suited to your project, we'll be honest with you.
The only way to find out... is to ask!

Author Information