Screw Pile
/skroo pyl/
Also known as: helical pile, screw anchor, ground screw, helical screw pile, mini pile
Definition
A steel pile with one or more helical flights that is rotated into the ground using specialist machinery. Screw piles can be installed quickly with minimal excavation or spoil, and can accept loads almost immediately after installation.
In Practice
Screw piles work well in soft to medium clays, silts, and sands but can be difficult to install in gravels or ground with obstructions. They are popular for extensions, decking, modular buildings, and situations where ground disturbance must be minimised or a traditional strip foundation would be disproportionately deep. A structural engineer must specify the pile diameter, helix configuration, and depth to achieve the required bearing capacity.
UK Building Regulations
Approved Document A - Structure
Screw pile foundations require structural engineer design and specification. Ground investigation should confirm soil conditions and identify any obstructions. Building Control approval is required.