Screw pile
Screw pile (helical pile): a steel deep foundation rotated into reactive or poor soil without excavation. No spoil, immediate load bearing, used on Class H/E/P sites.
Ask Chalkline about this →A screw pile (also called a helical pile) is a steel deep foundation consisting of a hollow steel shaft with one or more helix-shaped plates welded to it. The pile is rotated into the ground by a hydraulic drive head attached to an excavator, without excavating or generating spoil. Depth is confirmed not just by reaching design depth but by reaching the engineer’s design installation torque, which correlates to the pile’s bearing capacity. Screw piles are used on reactive Class H, E, and P sites, sloping blocks, and tight-access sites where a drill rig cannot work. All design and installation must comply with AS 2159:2009 (verified 2026-05-10, Blade Pile: Understanding AS 2159).
Also known as: helical pile, helical pier.
Category: Foundations.
Related
- Pier footings, the full process article covering screw piles, bored piers, and driven piles for residential builds
- Site classification, the AS 2870 soil class system that triggers pier footing use
- Reactive soil, the soil condition driving screw pile use across Australian residential builds
See also
- Footing, the general term for residential foundation elements
- Bored pier, the in-situ concrete alternative to screw piles
Last updated: 2026-05-10. Verified: 2026-05-10. Quarterly review for currency.