What Are Helical Pile Caps and Why Do They Matter?

October 29, 2021

Helical piles are kind of like icebergs.

The small part of the pile you see sticking out of the ground shows only a fraction of what's going on. Below ground, a pile can stretch over 100 feet deep into supportive soil. So it makes sense, as foundation contractors, that we focus on the components below ground. We get geotechnical reports, study soil conditions, and design accordingly. Paying attention to the soil helps us install rock-solid foundations.

But what's underground is only half the story.

The Mighty Helical Pile Cap

A helical foundation isn't "done" once the piles are in the ground. The piles still need to be transformed into something usable. This important task falls to the helical pile cap - an underappreciated part of a helical pile.

Helical pile caps are a key component of a helical pile with a critical job - connect the helical piles to whatever needs support. This could be a building, concrete slab, pipeline, communications tower - your imagination is pretty much the limit. These helical pile caps range from off the shelf designs to custom pieces of engineering art. Some are straightforward connections to concrete beams or slabs. Others are custom caps that make incredibly strong pile-to-pile connections or provide unique solutions to challenging projects.

Because of their custom nature, pile caps can be designed for virtually any application. This gives engineers and designers superb flexibility when it comes to planning a helical foundation. Instead of designing the project around the foundation, the foundation can be designed to perfectly fit the project.

The World of Pile Caps

I'd love to take you on a 3-hour tour of the immense range of pile caps out there. But, that would probably only be interesting for myself.

Instead, I want to show you a few key types of helical pile cap that are especially useful in commercial construction.

Pile to Pile Cap

A pile-to-pile cap ties multiple piles together. This is a common cap type for communication and transmission towers. You might also see it under light standards or signage. It excels at protecting against uplift and lateral forces.

Beam Pile Cap

This is a great example of an "off the shelf" pile cap. A beam pile cap provides support to a variety of beams. The cap in our example is designed for residential use, but the same concept applies to commercial piles. It's a quick, affordable, and simple way to tie a helical pile foundation to a beam.

Structural Pile Caps

The structural pile caps you see here are commonly used to support residential and commercial structures. They're a secure and economical way to couple a structure to the concrete foundation, typically with rebar or Nelson Stud details.

High Capacity Pile Caps

For high capacity projects, we use high capacity caps. These caps are made from thick steel, often more than 1" thick. They secure pile groupings and can support loads into the hundreds of kips. A mighty pile cap for a mighty foundation.

Underpinning Pile Caps

One of the common uses for helical piles is underpinning support to structures. This cleverly-designed pile cap lets contractors use hydraulic jacks to raise the foundation, then secure it with these special caps. Underpinning pile caps are a quick and easy way to shore-up a failing foundation.

Helical Pile Caps Are a Big Deal

A helical pile could have a million pounds of capacity, but it would still be worthless without a quality engineered pile cap. It's easy to get caught up in talking about pile length, number of helices, shaft diameter, and all kinds of cool engineering questions. But, the humble pile cap deserves our attention and appreciation. Without them, helical piles would just be steel pipes sticking out of the ground.

So, if you're working with a helical pile company, ask them about their pile caps. If they're true experts, they'll be happy to obsess about them.

Have some questions about helical pile caps, or anything else related to foundations? Why not click here to get in touch with our friendly experts, we'd love to help you find the right answers.