Screw piles
All pile types and their advantages.
What is frost depth?
Frost depth is how deep the ground can freeze in a severe winter. In Belgium a frost-free foundation depth of about 0.6 to 0.8 m is used in practice.
How deep do we go?
- Ground screws for buildings and structures that must not move: at least below frost depth, in practice 1.2 m or more
- All piles and screws from our pile calculator go at least 1.2 m deep
- Short 0.8 m screws we use only for light applications such as fences
- Screw piles go further until the helix sits in a bearing layer: 6, 10 or even 15 m for homes or soft ground
Frost and clay
On clay, drought counts as well as frost: the seasons act down to about 1.5 m. For heavier structures on clay we therefore go deeper than frost alone would require.
In the design too
When designing a screw pile we do not count the top metre of soil for friction along the pile: that zone can dry out, freeze or has been backfilled.
Soiltek is a specialist contractor, not an engineering firm. We provide the manufacturer's product data and align the pile proposal with your structural engineer.