Screw pile foundations - what are they?

You may have seen home additions in Calgary that appear to be on posts such as in the picture below. Theses posts are called Screw Piles and they are a bit of a game-changer in the construction industry. These innovative foundations offer a host of benefits along with a few limitations and are worth considering for your residential construction project.

Screw pile foundations are also known as ‘helical pier foundations’ or ‘screw pier foundations’. They are what they sound like - giant screws or long galvanized steel shafts with helical plates. They are screwed into the ground to below frost line and provide structural stability and support. The helical plates provide the anchor in the ground below the frost line, thus mitigating the structure being subjected to frost heave.

Unlike traditional concrete foundations, screw piles can be installed quickly and with minimal environmental disruption.

Diagram showing the different parts of screw piles and how they should be positioned in the ground.

I’ve summarized some of the advantages and disadvantages below:

A geotechnical survey and/or an engineer with knowledge of the soils in your project area are essential if you are considering screw pile foundations.

Despite their limitations, screw pile foundations remain a popular choice for many construction projects due to their impressive load-bearing capacity, versatility, and efficiency.