Benefits of Helical Pile Foundations in Calgary
What is the purpose of a helical pile?
Helical piles also called helical piers are an engineered steel ground anchor foundation. A deep ground foundation system may consist of one or many helical piles. These helical screw piles transfer structural loads down below the surface of the earth where the soil is stable. With a helical blade on one end these steel screw piles are installed into the soil like a screw. Once anchored into the ground, helical piles provide a support in which structures can be built upon. This type of foundation can be used in many building applications. Quite often helical piers can be used in place of concrete pile applications.
Are Helical Piles Better Than Concrete?
There are many advantages to using helical piles vs concrete piles. The greatest advantage to using helical piles is evident during long winters where the ground freezes. Heavy clay based soil conditions like that found in the Calgary area are ideal for both concrete and helical piles. But the colder climate in Calgary does not suit concrete piles. Concrete piles have been used in Alberta construction projects for decades but there has always been an issue. When the soil around a concrete pile freezes it is common for the concrete to crack at the frost line. Once a piling has cracked moisture then penetrates the pile. This moisture then expands as it freezes and a phenomenon known as frost heaving occurs lifting the top of the pile out of the ground.
Helical piles are steel and cannot crack under these conditions. With the pile helix located well below the frost line a properly installed helical pile is not susceptible to frost heaving. This is why helical piers are a more stable and long lasting deep foundation than concrete.
How deep can helical piles go?
We recommend all helical piles installations in Calgary start with a 10’ pile. During a long and cold winter in Calgary we can sometimes find frost 7’ feet down. Going 10’ feet deep with your helix ensures the load bearing part of the pile is well below any soil that could freeze. Poor soil conditions and engineering requirements can mandate the need to install a helical pier deeper than 10’ into the ground.
Helical piles require a specified applied torque to meet their load bearing requirements. Sometimes poor soil conditions are discovered when the piles are being installed. The solution to this issue is to go deeper into the earth with the helix of the pilings. In Calgary we’ve seen poor soil require piles to go down to 30’ before encountering solid ground. To go deeper with helical piers the installer simply adds extensions until the required applied torque is met. Though extensions create additional cost, they’re a minimal expense compared to the alternative.
In the case of concrete piles deeper holes are needed to add depth to the pile. Drilling deeper for concrete piles adds complications and cost to the installation process. More drilling creates more fill that has to be hauled away at an additional cost. And sometimes the original drilling equipment on site is not sufficient to drill deeper holes. When this occurs projects are put on hold until larger drilling equipment can be contracted and brought on site.
Advantages of Helical Piers
Helical pile installation is fast and non-invasive. Because of this the overall costs including materials are much lower than that of alternative deep foundations. By offering a long lasting stable foundation at a lower cost and less mess it is easy to understand why helical piers are popular to use. Great for residential applications such as decks, sheds, preformed stairs, cement slabs and much more. Contact the excerpt at Torsion Screw Piles Calgary for a free estimate today.