Helical Pier Systems
What Are Helical Piers?
Helical pier systems, or helical foundation repair systems, are also called helical piers or piles.
This is a type of deep foundation repair that stabilizes existing structures, but the system can also be installed before construction to ensure that the building will remain stable. Helical pier systems are screwed into the ground, like a corkscrew, until they reach stable soil.
Helical Pier Systems – The History
The helical pier was invented by Irish engineer, Alexander Mitchell, as a method to stabilize lighthouses and other structures built on mud and sand. Originally called a screw-pile, the piers were made of cast or wrought iron. The design and installation method provided more stability in the mud and sand, than that of straight piers.
In fact, the first helical foundation system was installed in the 1830s. The first helical, or screw pile, installed in the US was at Brandywine Shoal, Delaware Bay. Moreover, the lighthouse at Brandywine Shoal replaced a straight pier lighthouse, which was destroyed by ice flows.
In addition to installing the new lighthouse on helical piles, the tops of the piles were interconnected. This created an ice breaker, which would further protect the lighthouse from the heavy ice floes.
In the US, helical piles quickly caught on after the Civil War. The Lighthouse Board made the decision to replace the lighthouse vessels currently serving in interior waterways (bays, sounds and rivers) with screw pile lighthouses. Over 100 screw pile lighthouses were constructed to replace the older light vessels.
To clarify, many screw pile lighthouses have withstood the test of time. The Roanoke River Light, which was built in 1877, is the last screw pile lighthouse standing in North Carolina. The Carysfort Reef Light, located four miles outside of Key Largo, FL, was constructed in 1852. Carysfort is the oldest screw pile lighthouse that remains in service in the United States.
Helical Pier Systems – How They Work
Once helical pier systems are installed, a bracket is placed under the foundation footing. This bracket keeps the helical pier systems in place, which ensures the structure is supported by the pier.
After helical pier systems are installed, the results can help lift the structure – which can restore the value of your home.
Another helical foundation system is a soil nail or helical anchor. Like the pier, the anchor screws into the ground. Furthermore, a bracket is placed on the interior wall and the anchor is drilled into the soil. As a result, the wall straightens and stabilizes.
Helical anchors are used to stabilize bowed or cracked basement foundations. No matter how severely damaged walls can be, they are safely repaired using helical anchors.
Helical Pier Systems – The Science
JES uses FSI helical foundation systems, which have been extensively tested, in accordance with the International Code Council (ICC). The piers are designed, in accordance with the ICC-ES AC358 criteria, for geometry of the helical blades.
This means the helical foundation systems we use are safe, effective and built to last. Specifically, the helical blade is the portion of the pier that looks like the wings on a screw.
These blades are spaced to ensure that the pier is strong and installs easily. Therefore, there is minimal disruption to the surrounding soil.
Helical Pier Systems – The Benefits
One of the many benefits of helical foundation systems is that installation doesn’t generate any spoils. This means that no digging is required, so you don’t have to worry about cleaning up piles of dirt and debris.
Unlike piles, helical piers don’t create vibration during installation. Piles are typically driven into the ground, which can damage surrounding structures and create additional liabilities.
Need Foundation Repair?
If you’re not sure of the source of your foundation problem, give us a call at 866-370-4816, and schedule a free inspection. We’ll find the cause of the problem, and not to mention, help you find the perfect solution.
Footnotes: * The ICC does not have standards for every foundation system currently available. FSI tests in accordance with ICC standards when available. If testing standards are not available, FSI conducts extensive internal tests with their team of Professional Engineers to ensure strength, accuracy, load bearing and safety meet or exceed other comparable ICC and industry standards.