Introduction

Helical piles have become a common foundation solution not just across the United States, but throughout the world. Capable of supporting everything from small residential projects to large-scale commercial construction, they're a favorite among homeowners and professionals alike thanks to their high performance.
Despite this wide-spread adoption, helical piles are still somewhat of an unknown here in Central New York. Our team at CDP Excavating has spoken to numerous contractors, engineers, and architects, who are unfamiliar with this unique option that could save them major time and effort on their foundation.
That's why we decided to answer eight common helical pile foundation questions to demystify this nearly two-hundred year old technology that is transforming how we build in this region.
Whether you've never heard of helical piles or are simply looking to expand your knowledge, by the end of this article you'll have a clear idea of how they work and the surprising benefits your project could enjoy.

What is a Helical Pile Foundation?

A helical pile is a type of deep foundation that is installed below the surface of the ground to support a structure. Passing through weak and loose layers of soil, helical piles anchor themselves in firm strata to resist ground movement and hold significant structural loads.

The pile consists of a central steel shaft, typically made from sturdy pipe. However, solid square shafts are also available for certain applications.

Attached to the pile shaft are helical-shaped blades, known as helix plates, which help advance the pile into the ground and provide load resistance. The soil exerts pressure on the top and bottom of the helix plates which prevent the pile from moving up, down, or side-to-side.

At the top of the pile, a variety of adapters can be attached to easily transition to virtually any project or configuration. You can even tie multiple helical piles together using a grillage, allowing for massive load capacities.

This foundation was first invented in the 1830's and originally intended to provide support for lighthouses, bridges, and piers, that were built in challenging soil conditions. As the decades progressed, the technology would find use under a huge range of building projects thanks to its unique benefits.

Today helical foundations are backed by almost two centuries of research, testing, and real-world results. In fact you can find structures like the Brighton Pier in the U.K. which have been sitting on helical piles for over one-hundred and fifty years.

How are Helical Piles Different Than Concrete or Driven Pile Foundations?

As an alternative solution to poured concrete or driven pile foundations, helical piles are similar in some ways and unique in many others.
First, let's quickly review poured concrete and driven piles...
A poured concrete foundation involves excavating an area of the ground, setting a form, adding reinforcements, then pouring concrete into the void. Poured concrete has been around for a very long time and is commonly used throughout Central New York.
Driven piles are typically made from pre-cast concrete or steel beams. A pile driver uses hydraulic or diesel power to operate a large hammer that drives the pile into the ground. This solution is often used for sites that would not support a poured concrete foundation, usually because the ground is too soft for effective excavation.
While poured concrete and driven piles are typical foundation options, they do have some drawbacks. Extensive site preparation, large amounts of bulky equipment, slow installation, and questionable performance in difficult soil conditions are a few examples.
Helical piles, on the other hand, are installed by rotating them into the ground. No disruptive excavation or vibration-heavy hammering required. This dramatically reduces site preparation, impacts on the local environment, and overall construction timelines.
To simplify the comparison between poured concrete, driven piles, and helical piles, we've put together an easy chart:

How Do You Install Helical Piles?

As we mentioned in the previous section, helical piles are installed by rotating them into the ground. This ensures they smoothly advance into firm layers without disrupting the delicate ground, maintaining the integrity of the soil.

The process for installing a helical pile foundation is straightforward and very easy to understand:

What Can You Build on a Helical Pile Foundation?

This is a tough question, because if anything it should read, "What can't you build on a helical pile foundation?"

Over the course of their nearly two-hundred year history helical piles have been used to form a solid foundation for almost any structure you can think of. You can find them under houses, decks, cottages and cabins, boat docks, solar panels, power lines, and a whole lot more!

Essentially, you can use a helical pile for anything that demands deep and dependable support.

They are a well-understood and respected foundation, used in both light residential and heavy commercial construction. For example, in the province of Alberta, Canada, they built a 3,300 acre 465 MW solar farm on more than 220,000 helical piles!

New York City also has many structures resting on a helical foundation, including a 22 story multi-use building mixing retail stores and condo units.

So, when we say it's a tough question to answer, it's because there aren't really any limits to the type of structure you can build on helical piles. That doesn't mean they're the right solution for every project, but they also aren't limited to specific structures.

How Strong are Helical Pile Foundations?

Very strong.
Okay, you probably want a more detailed answer! Now this is an interesting question, because in some ways it's kind of "backwards". Instead of asking how strong a helical foundation can be, you really should be asking how strong your helical foundation needs to be.
Some helical pile foundations support well over a million pounds, like this oil and gas slug catcher foundation installed by a company in Texas. It's an impressive project that showcases what this technology is truly capable of.
Other helical foundations only need to support a few thousand pounds, which they will also happily do. Think of it like a sliding scale, with helical piles representing a foundation solution for both the low and high ends.
The ultimate load capacity, or strength, of a helical pile comes down to a few key factors:
1: Size of helical pile and helix plates2: Soil conditions3: Torque achieved on installation
There are other forces at play, but those are the three big ones. It's difficult to say what the load capacity of your helical foundation might be, as we can't know those factors without assessing your project.
However, thanks to the unique design of a helical pile, we can engineer a foundation solution that more than meets your load requirements and soil conditions.

How Long Will a Helical Pile Last?

The Thomas Point Shoal Lighthouse has been standing in the Chesapeake Bay since 1875 on case iron screw piles, withstanding countless storms and ice flows.

One of the most important aspects of a foundation is how long it will last under your structure. You don't want to be dealing with constant repairs and structural problems because of weak or failing support.

Thankfully, longevity is not a concern with helical piles. Owing to their steel construction, they're more than capable of outlasting practically any structure they support. It's one of the reasons the technology has found frequent use in marine environments or areas with high water tables.

Historically, helical piles were made from heavy cast iron that relied on immense thickness to slow the rate of corrosion. This worked very well, as you can still find lighthouses that have been sitting for over one-hundred fifty years on cast iron helical piles.

Modern helical foundations are manufactured from steel that is vastly superior to the cast iron of old. Strong, durable, lightweight, and extremely resistant to the effects of corrosion. A properly-installed helical pile in typical soil conditions will easily last fifty years and beyond.

In areas where the soil composition makes it more corrosive, helical piles can be given a galvanized coating to increase their protection and ensure long-term performance.

It's amazing to think you could remove a helical pile in fifty or even one-hundred years and it would very likely still be in good condition. But, that's the benefit of this proven technology!

Can I Install Helical Piles Myself?

Many great DIY projects exist for ambitiously-minded people, but installing a helical pile foundation is not one of them. We're not just saying that because our team at CDP Excavating installs helical foundations, either.

The reason that helical piles aren't a do-it-yourself option comes down to the equipment, training, and skill, required to do the job right.

First, the equipment. You'll need something called a hydraulic drive, which provides the rotational force needed to advance the pile downwards. These are usually attached to an excavator or skidsteer. There are many different sizes of hydraulic drives on the market to suit different helical pile diameters. Roughly speaking, bigger piles will require a stronger drive to properly install.

Having a hydraulic drive and something to mount it on is only one part of the installation equation. You need to know how to effectively, and safely, operate the equipment to install a helical pile. While it's a straightforward process, there's also many places it can go wrong if you don't know what you're doing.

Installing a safe, sturdy, and long-lasting foundation is a skill. Any mistakes made in this crucial phase of your project will cause a ripple-effect that could have disastrous consequences in the future. So, while we love the DIY spirit, we strongly recommend that helical pile installation is left to the professionals.

How Much Does a Helical Foundation Cost?

Here we are, the biggest question on almost everyone's mind when we're talking to them about a helical pile foundation.

What's it gonna cost?

Unfortunately, this is another one of those "hard to answer" questions. We're not trying to hide anything, but when you consider how many factors can influence the cost of a helical foundation you realize how tricky a straightforward answer is.

When we're preparing a quote for your helical foundation, here's just some of the things that impact the cost:
● Structural load requirements● Size of project● Foundation design● Type of helical piles required● Soil conditions and location● Environmental restrictions or considerations

Let's use an example to illustrate our point.

Pretend you're looking to build a small cottage in an area with good quality soil and easy access. Since the foundation will be straightforward and won't need to be installed too deep, your costs will be on the lower end of the scale.

Now, take that same small cottage and build it near a shoreline that has very weak and saturated soils. This foundation will need to be installed deeper and could even require larger helical piles to overcome the difficult conditions. Your costs would be higher, because even though it's the same cottage your ground conditions are more demanding.

Generally speaking, a helical pile foundation sits somewhere in the middle of other solutions in terms of costs. Poured concrete will often be cheaper, driven piles can be more expensive.

But, remember that the "face value" cost of a foundation doesn't tell the whole story. For instance, while poured concrete may be cheaper it also demands much more site preparation and time to install. When you consider the speed and ease of a helical foundation install, you'll discover that you save money through reduced construction timelines and long-lasting support.

Conclusion

There you have it, answers to eight of the most common helical pile questions! We touched on many different aspects of this foundation solution throughout the article, so let's summarize what we covered.

We hope this article was able to clarify the key aspects of helical pile foundations and give you insight into why they've become so popular across the United States.
Even though the construction community has been slow to adopt them in Central New York, they offer outstanding benefits compared to the "traditional" foundation solutions.

If you'd like to see how a helical pile foundation could help you build your projects on a faster, firmer, more eco-friendly support, get in touch with our team at CDP Excavating. We'll make your entire foundation process a breeze from our first conversation to the final pile in the ground.

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