Are screw piles stronger than frost and rock?

Are screw piles stronger than frost and rock?

It is well known that north of the 45th parallel, the winter season is hard on the foundation of any building. Freezing and thawing periods are often the cause of deterioration and damage to them. And as if soil movements were not enough, there is also rock! Rock, which is present in many regions of Quebec and Canada, also poses a greater challenge when the time comes to excavate the ground to build the foundation of a new building or an addition to a building.

Screw piles are one of the options available. But are they strong enough to withstand ground movement caused by freezing and thawing? Are they strong enough to be installed in rock? They certainly are!

The effectiveness of screw piles in freezing and thawing periods

Thawing periods are becoming more and more frequent. In southern regions, it is not uncommon to have almost ten such periods per winter. Screw piles are designed to resist ground movements, such as uprooting.

The lower part of the pile consists of a blade that does all the work. It is designed to support the load of the project and ensure its stability. By being aimed into the ground, the blade prevents the pile from sinking further or rising. It serves as both a support and an anchor.

The galvanized steel used in the manufacturing of screw piles is resistant to extreme cold. The smooth surface of the pile, combined with a smaller ground contact area than a sonotube, allows the pile to better resist pull-out. With very little grip, the pile is much less likely to move as soil movement slides along the tube.

Installing the right length of pile

But you still have to choose the right length of pile according to the frost level of your region. To prevent a pile from moving during freezing and thawing periods, it is imperative that the pile be installed so that the blade is below the frost level. The northern regions of Quebec and Canada have.

For example, if you are building an extension on piles in Sherbrooke where the frost level is approximately 1.33 m (52 inches), you will need 2.13 m (7 foot) piles. On the other hand, if you are in Amos, where the frost level is 1.78 m (70 inches), the installation of 3.05 m (10 foot) piles is strongly recommended.

The use of screw piles on rock

Building on rock is always a bit stressful. The word “rock” is not used in expressions such as “rock solid” for nothing… it is an extremely hard material and difficult to dig. However, the fact that it is unyielding does not prevent the use of screw piles. It is indeed possible to install screw piles in soil where rock is present.

Depending on the depth of the rock, the installation technique will be different. If the rock is deeper than 1.22 m (4 feet), the installation technique remains the same. The piles will be screwed into the ground to the rock where they will be supported and will not move.

If the rock is at a shallower depth, then a different installation technique is required. A specialized anchor tube will be used for your project.

The installation of piles screwed into the rock is solid!

Are screw piles suitable for your project?

Screw piles offer an advantageous solution for many projects. Whether you live in the north, south, east, west, in the mountains, on a lake or downtown, you can choose screw piles. Ask one of our advisors for more information