Rock drilling for piling is needed when foundation piles must pass through or be anchored into hard rock that cannot be penetrated by standard rotary auger equipment. ASAP Piling uses down-hole hammer equipment to drill through Melbourne's volcanic basalt rock — found across the inner northern and western suburbs — and switches to this specialist equipment when rock is encountered during standard bored pier drilling. Rock drilling projects completed across Melbourne since 2001.
Melbourne sits on surprisingly varied ground. Much of the city's inner north and west is underlain by volcanic basalt — in some suburbs this rock starts only 2 to 3 metres below the surface. For any piling project in these areas, rock drilling is part of the job.
Where Rock Is Found in Melbourne
Inner Northern Suburbs — Essendon, Moonee Ponds, Ascot Vale, Brunswick, Coburg, Strathmore
Basalt rock commonly within 2 to 5 metres of the surface. A large proportion of piling jobs here require rock drilling.
Western Suburbs — Footscray, Yarraville, Williamstown, Sunshine, Keilor
Rock depth varies but can be very shallow across this zone.
Inner Melbourne — Docklands, West Melbourne, North Melbourne
Rock can appear in deeper excavations across this area.
Mornington Peninsula — Red Hill and Mt Eliza
Localised rock on higher ground in elevated areas.
Rock depth and type varies even within a single street. The only reliable way to know what's below your specific site is a soil investigation by a geotechnical engineer. ASAP Piling can advise on the likelihood of rock based on your suburb, but a formal investigation is needed before the engineer can design the footing system.
How ASAP Piling Drills Through Rock
Down-hole Hammer (DTH): A pneumatic hammer at the bottom of the drill string strikes a hardened drill bit at high speed, breaking rock into fragments that are flushed to the surface by exhaust air. This is the fastest and most effective approach for Melbourne's hard basalt — it is ASAP Piling's primary rock drilling method.
Rock Roller Bits (Tricone): Three rotating toothed cones crush and grind the rock face as the drill turns. Used for softer or weathered rock where the full force of the down-hole hammer is not needed. Works with a broader range of rig configurations.
Rock Socketed Piles
When a pile needs to anchor into rock — not just pass through it — the engineer designs a rock socket: a length of pile drilled into solid rock so the building's load transfers directly into the rock. The socket depth is calculated by the engineer based on the rock quality and strength found in the soil investigation, combined with the building's structural loads.
Call Nick on 0499 888 799 — have your soil report ready to discuss rock drilling pricing for your project.
Frequently Asked Questions
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