We drilled 128 CFA piles through water-charged beach sand to 14.3m, forming the shoring wall and foundations for a new beachfront home.
Location: Wamberal, Central Coast NSW
Pile type: CFA (continuous flight auger) + screw piles
Piles: 128 CFA
Diameters: 450 mm and 600 mm
Total length: 1,085 lineal m
Max depth: 14.3 m
Ground: Water-charged beach sand
Scope: Contiguous shoring wall, foundations (2 levels), retaining wall and stair piles
Machinery: R210, Schwing SP1000 concrete pump, Kobelco 8t and 14t excavators
Completed: September 2026
We delivered CFA piling on the Central Coast for a new beachfront home. The 128 piles go through water-charged beach sand to a maximum depth of 14.3 m. The crew started on 26 August 2026 and finished on 29 September.
The home sits on a sloping beachfront block, so its foundations step across an upper and a lower ground level. We piled both levels and formed a contiguous shoring wall to retain the excavation. Screw piles carry the retaining wall and the beach stairs.
Sand below the water table has nothing holding it together. Drill an open bore and the walls slump in as the tool comes out, so the pile cannot form cleanly. Groundwater pushing in from the surrounding sand speeds that up.
The block added its own constraints. Homes sit close on both sides, and the wall had to retain the lower ground level cut without room to move.
A CFA piling rig drills a hollow-stem auger to design depth in one pass. We then withdraw the auger slowly while the Schwing SP1000 pumps concrete up through the stem. The auger and then the concrete support the sand the whole way, so the bore never stands open.
The same method formed the contiguous shoring wall and the foundation piles at both levels.
We finished the piling on 29 September 2026, about five weeks after the first rig arrived. The contiguous wall retains the lower ground level cut. The foundation piles at both levels are in, and the screw-piled retaining wall and beach stairs are complete. In total, 1,085 lineal metres of CFA pile went into the sand.
Planning a build on sand, a slope or high groundwater? Email your geotechnical report to sales@millentcivil.com.au or call 02 4578 0110, and we will recommend a buildable piling method.