Cable Trenching & Underground Conduit in Sydney & the Sutherland Shire

How we work

1. 1

   Free site visit and route walk

   We walk the run with you end to end, measure it, and note every surface along the way — lawn, garden bed, paving, concrete, driveway crossing — along with where the board is and where the machine can physically get in. Free within 100 km of Caringbah.

2. 2

   Design & itemised quote

   Priced ex-GST per metre of trench, with conduit, draw pits, cable, terminations, reinstatement and any rock allowance as their own visible lines. If ground conditions or the surface change the number, you can see which line moved and by how much.

3. 3

   BYDA enquiry and service location

   We lodge a BYDA enquiry before excavation, review the returned plans against the marked-out route, and prove known services by hand before the excavator moves. Anything found that isn't on a plan gets marked up and worked around, not through.

4. 4

   Excavation, conduit and cable pull

   The trench is cut to the depth the installation requires, conduit and a draw string laid, bends set so the cable can actually be pulled, cable drawn through and marker tape run in over the top before backfill starts.

5. 5

   Backfill, reinstatement, testing & certification

   Backfill compacted in layers so the trench line doesn't sink six months later, the surface made good, circuits tested and recorded, and the Certificate of Compliance for Electrical Work issued for the licensed portion.

Compliance & licensing

What moves the price

Trenching is quoted itemised ex-GST, priced per metre of trench with conduit, pits, cable and reinstatement on their own lines. What moves the number:

• Run length — the base measure everything else multiplies against, taken on site rather than off a map
• Ground type — the biggest variable in the Shire; soil digs, shale slows the machine, and Hawkesbury sandstone changes the job entirely
• Depth — set by what the trench runs under and how the cable is protected, not chosen for convenience
• Existing services and obstacles — water, gas, comms, irrigation, tree roots and old unmapped runs all mean hand-digging sections of the route
• Reinstatement surface — turf is one price, lifting and relaying pavers another, and saw-cutting and patching concrete another again
• Spoil — whether the material can stay on site or has to be carted away
• Plant access — a machine that can drive to the route versus a run that has to be hand-dug through a side gate
• Traffic control and permits — where the route leaves private property and crosses a footpath, nature strip or road

The trench is the expensive part, not the conduit — so while it's open, lay the spare. A second duct for data, a security cable or a future pool pump costs very little today and means never digging the same line twice.

Frequently asked

How deep does an underground power cable have to be buried in NSW?

There isn't one depth. The AS/NZS 3000 wiring rules set it as a set of cases, and which case applies depends on what's above the trench — garden and lawn, paving, or a driveway carrying vehicles — and on whether the cable is direct-buried or run in conduit, with additional mechanical protection allowing shallower installation in some situations. Marker tape above the cable is part of the same requirement. We work the depth out against the rules for your actual route at the site visit rather than quoting a number down the phone.

Do I need a Before You Dig enquiry to dig on my own property?

You should, and it costs nothing. BYDA is a free enquiry service — you lodge the dig area and the registered asset owners send back plans for what they have in it. Two limits are worth knowing: it only covers utilities registered with the service, so a private cable a previous owner ran to a shed is on nobody's plan, and the plans it returns are indicative, not survey-accurate. That's why we lodge a BYDA enquiry before excavation and still prove the route by hand over known services before any machine starts.

What does cable trenching cost in the Sutherland Shire?

Ground type first — it's the single biggest variable here. Beach sand around Cronulla and Kurnell digs quickly but wants care with trench walls; shale is slower; Hawkesbury sandstone is a different job again. After that it's metres of run, the depth the installation requires, what surface has to be reinstated, and whether a machine can reach the route or it has to be hand-dug through a side gate. It's quoted itemised ex-GST per metre after a free site visit, with the variables on separate lines so you can see which one is driving the total.

What happens if the trench hits sandstone?

Much of the Shire is Hawkesbury sandstone under a thin skin of soil, so we look for it at the site visit before anything is priced: outcrops in the garden, rock ledges showing in the fall of the block, what came out of the pool or the neighbour's footings, and how deep the beds are. That tells us the likelihood, not the exact line where rock starts — nobody knows that until the bucket is in the ground. So rock goes on the quote as its own visible allowance rather than arriving later as a variation, and you can see it before you commit. If we do hit it, there are usually three ways out and we'll talk through them on site: reroute around the ledge, which is often the cheapest; run shallower with additional mechanical protection where the wiring rules allow it for that route; or keep the run above ground along a structure or fence line where the site suits it. What we won't do is quietly leave a cable too shallow because the rock was hard.

Can power, data and security cables go in the same trench?

Yes, and one trench beats three. They go in separate conduits with the separation the wiring rules require between the power cable and the extra-low-voltage runs — that separation is measured and set, not eyeballed, and where the route can't give it, the rules allow other methods such as a barrier or suitably rated cable. Doing it as one excavation means one lot of digging, one lot of reinstatement, one set of marker tape, and no second trench across a lawn you've only just got back.

Who can run underground power to a shed or granny flat?

The digging itself isn't licensed electrical work — but the cable in the trench, the connection at the switchboard, the sub-board at the far end and the compliance certificate all are, and in NSW that's a licensed electrical contractor's work. We hold Electrical Contractor Licence 350318C and do both halves, which is the point: the crew that decides how deep the trench goes is the crew that has to certify the cable in it. If a trench is dug before the electrical scope is agreed, it's routinely dug twice.

Do you put the lawn, pavers or driveway back afterwards?

Yes, and it's a quoted line on the itemised quote, not an assumption. Backfill goes in compacted in layers so the trench line doesn't settle into a visible dip over the next few months. Being straight about the finish: turf knits back over a season and disappears; pavers lifted carefully and relaid usually come back very close, especially with a few spares. A concrete path or driveway can't be made invisible — a saw-cut and patch will always read as a patch, because new concrete never matches the colour and finish of cured. Where that matters, we look at routing around the slab at the site visit instead of through it.

What paperwork do I get after underground cable work?

A Certificate of Compliance for Electrical Work (CCEW) for the licensed electrical portion, with the test results recorded, plus a record of the route as installed — where the conduit actually runs, how deep, and what's in it. The second one matters more than people expect. The next person to put a shovel or a fence post in that ground could be a landscaper, a plumber or the owner after you, and an as-installed route is the difference between them working around your cable and finding it the hard way.