Helical Piles Uncovered: 8 Questions That Can Change How You Build
CDP Excavating and Demolition
To deliver unbelievably-good excavation, demolition, and helical pile foundation services to homeowners and contractors.
Helical piles have become a common foundation solution not just in 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, there's still a few misconceptions about helical piles that persist here in Central New York where our company is located.
That's why we're answering eight common helical pile foundation questions that will demystify this nearly two-hundred year old technology that's rapidly transforming how we build.
What is a Helical Pile Foundation?
A helical pile is a type of deep foundation that excels at resisting ground movement and supporting significant structural loads in compression and tension.
The main body is comprised of a central steel shaft, typically made from round pipe. 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 these helix plates which prevents a helical 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.
How are Helical Piles Different Than Concrete or Driven Pile Foundations?
While poured concrete and driven piles are typical foundation options, they can have some drawbacks.
Extensive site preparation, large amounts of bulky equipment, slow installation, and potentially questionable performance in difficult soil conditions are a few examples.
Helical piles, on the other hand, are installed by smoothly rotating them into the ground using straightforward equipment such as an excavator. That means no disruptive excavation, loud hammering, or specialty machines.
This dramatically reduces site preparation, disturbance to the environment, and overall construction timelines.
Another key difference is the fact that helical piles have the helix plate, a feature that makes them ideal for weak or loose soil conditions as it creates a large surface area for the soil to exert pressure on.
If a helical pile is not installed to an impassable layer (i.e. bedrock), it's considered a "floating" pile. In these cases, it's the action of the soil on the helix plate(s) which prevents movement.
When a pile is installed to an impassable layer like bedrock, load capacities can increase as compressive strength comes from the pile shaft itself. However, the helix plate still plays an important role in uplift resistance.
The main differences between a helical pile foundation and other solutions are:
How Do You Install Helical Piles?
1: Foundation Design
There are many sizes of helical pile available, each intended for different loads or to overcome specific soil challenges. So, the first step is to devise a design that will deliver safe and efficient support. This is done by assessing your structure, load requirements, soil conditions, environmental considerations, and other factors.
2: Deliver Materials & Equipment to Site
Thanks to their compact footprint and minimal equipment requirements, transporting everything to your site is a smooth and painless process. Helical piles can be stored on-site to eliminate truckloads of material arriving in the midst of construction.
3: Install Helical Piles
Each pile is attached to the hydraulic drive and positioned above pre-marked locations. As the pile is installed, we monitor the torque required to advance it into the ground. These figures tell us what conditions the pile is facing and confirms when it has been installed to specification.
4: Attach Pile Adapters
Once the piles are properly installed, they are carefully leveled to create a perfect platform for your structure. Pile adapters are attached to the tops for an easy transition to whatever you're building.
What Can 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.
How Strong are Helical Pile Foundations?
Some helical pile foundations support well over a million pounds, like this large oil and gas slug catcher foundation installed by a company in Texas. An impressive project that showcases what the technology is capable of.
Other helical foundations only need to support a few thousand pounds, which they also happily do. Think of it like a sliding scale, with helical piles representing a foundation solution for both the low and high end.
Thanks to the unique design of a helical pile, our trusted engineering partners can create a foundation solution that will more than meet your load requirements and soil conditions.
How Long Will a Helical Pile Last?
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.
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 likely well over a century.
In areas where the soil composition makes it more corrosive, helical piles can be given a galvanized coating or use other techniques to increase their protection and ensure long-term performance.
Can I Install Helical Piles Myself?
Ambitious contractors often wonder if they can simply buy the right attachment and install helical piles themselves. This, in our opinion, is not generally a good idea.
(We're not just saying that because our team at CDP Excavating installs helical foundations, either!)
The reason that you can't really "jump into" installing helical piles comes down to the equipment, training, and skill, that's required to do the job right. There's many places it can go wrong if you don't know what you're doing, and you may not even recognize the problem until it's too late.
Installing a safe, sturdy, and long-lasting foundation is a skill. Any mistakes made in this crucial phase of your project could have disastrous consequences in the future.
We appreciate contractors trying to save a buck, but this is one place where it's better to pay someone who knows what they're doing.
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:
Remember that the "face value" cost of a foundation doesn't tell the whole story. For example, poured concrete may be cheaper but demands more site preparation and time to install.
When you consider the speed and ease of a helical foundation, you'll find it often saves money overall through reduced construction timelines and long-lasting performance.
Conclusion
We hope this article was able to give some insights into why helical piles have become such a popular foundation solution across the United States.
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.