When you’re building a new home or commercial property and a geotechnical engineering firm has determined that your soil is “unsuitable,” additional support is required.
The ground soil is not strong enough to support the building. Two common options are installing helical piers or concrete caissons around your foundation perimeter.
Keep reading below to learn about whether to choose helical piers vs. concrete caissons to secure your foundation.
What are Helical Piers?
Helical piers resemble large steel screws that are advanced or augured into the ground. They’re made of galvanized steel to better withstand the elements.
These piers are driven into the ground to a predetermined depth based on the soil borings. Installers need to find the right torque before the piers are ready to support the structure. The helical pier ranges in size from a 1.5-inch square shaft to a 3.5-inch round shaft.
Most of the helical pier installations we deal with are advanced 21-35 feet into the ground to achieve proper load-bearing stratum or to find the “good soil” needed to support the building.
One of the biggest advantages of installing helical piers is that it causes very little disruption to the ground soil. No serious excavation is needed, unlike in concrete jobs where a frame for concrete needs to be dug out.
What are Concrete Caissons?
A concrete caisson is a prefabricated hollow box or cylinder sunk into the ground and filled with concrete. These can be used for large jobs like bridge piers or concrete dams.
When used to secure the foundation of a home or commercial building, they are constructed above the ground and then lowered into excavated soil.
Although concrete caissons are strong and watertight, they must be excavated into the ground to create the diameter all the way to the predetermined depth. This disrupts the ground soil in an environment that has already been deemed “unsuitable” for building because it’s not strong or dense enough.
Here’s something else to consider: when installing concrete, all of the spoils from the excavated material must be removed and relocated. This adds considerable labor time to the project.
Choosing Helical Piers vs. Concrete Caissons — Which Is Better?
So, what’s the best choice: helical piers or concrete caissons?
United Structural Systems of Illinois, Inc. has worked with it all, and we recommend that customers choose helical piers, which are also known as helical piles.
Helical pier installation is quicker, easier, and less disruptive to your already fragile soil.
Concrete caissons are generally heavier than helical piers. If you have poor soil conditions, you don’t want to unnecessarily increase the total weight of the finished structure.
We also want to point out that helical piles are more expensive than concrete because they’re made of galvanized steel, but the set-up and labor portion to install caissons far outweighs the material savings.
Secure Your Foundation
We hope this blog taught you a lot about using helical piers vs. concrete caissons for foundations. While you’re free to choose whichever option works best for your property and budget, we recommend going with helical pier foundation installation.
Call us today at 847-382-2882 if you have any questions about residential or commercial helical piers installation, or if you’d like to schedule a free consultation.