Rock Excavation on the Central Coast

What rock excavation on the Central Coast actually involves

The same survey says sandstone boulders, which it calls floaters, may be present in the soil of the Terrigal Formation's Erina landscape, so rock can turn up in a dig that started in soil. Where Hawkesbury Sandstone is at the surface, the soils are shallow, generally under 50 centimetres deep, with rock outcrop. Council's geotechnical chapter names both formations, with Patonga Claystone, in the matrix it uses to decide when a sloping lot needs a geotechnical report.

Noise, vibration and working hours

NSW's construction noise guideline names rock breaking and rock hammering among the work neighbours find most annoying. It recommends Monday to Friday 7am to 6pm and Saturday 8am to 1pm, with no work on Sundays or public holidays, but says those hours are not mandatory; a job with a development consent follows the hours in its conditions, and under a complying development certificate for a house, construction may only be carried out from 7am to 5pm, Monday to Saturday.

SafeWork's excavation code says it is important that nearby buildings aren't affected by vibration or concussion from the work, and that digging below the footing of a structure, a retaining wall included, should be assessed by a competent person and supported by a designed system. If explosives are proposed, only a licensed and experienced person may use them, and the regulator has to be notified.

Rock Excavation on the Central Coast — common questions

Does rock change the quote?

It can. No government or professional body publishes a price for rock excavation or ties rock type to cost, so ask the provider how the quote treats rock found partway through the job.

Can excavated rock go to Council's tip?

Council's list of accepted waste names clean soil, and bricks, roof tiles, pavers and concrete, but not rock, so ask where excavated rock is going before it leaves the block.

Does a steep rocky block need an engineer?

Possibly. Council's geotechnical chapter applies to every lot on the Central Coast, and where its slope and geology matrix puts a lot in Hazard Category 2 or higher, a development application needs a geotechnical report covering the site and the lots beside it.