How does core hole drilling work when you're installing or replacing a power pole? A core hole is bored into the ground with a truck mounted auger to a diameter and depth set by your pole's size, material and the soil it's going into, the pole is then stood in the hole, backfilled or set in concrete, and left to cure before any conductor load goes onto it. Get the hole wrong and even a brand new pole can start leaning within a few years, which is why this step is Level 2 ASP work rather than something a general contractor should attempt.

⚡ Quick Answers: Core Hole Drilling for Power Poles

What is core hole drilling? Boring a hole in the ground with an auger or drilling rig so a new or replacement power pole can be set to the correct depth and diameter.
How deep does the hole need to be? Typically 1.0 to 1.9 metres depending on the pole's free length above ground and the soil quality on your property.
How wide does the hole need to be? At least 100mm wider than the pole's own diameter, so the pole sits centred with room for backfill or concrete all round.
What if there's sandstone or rock under my yard? A specialist rig can core through it, and the required depth can actually reduce once the pole is anchored in solid rock.
Do I need council approval? Often yes for a new private pole, and your Level 2 ASP will tell you upfront if your job needs it before drilling starts.
Can I dig the hole myself and just have an electrician stand the pole? No. Getting the depth, diameter and soil assessment wrong is one of the most common causes of a leaning or unstable pole, so this needs to be done by the accredited provider carrying out the whole installation.

1. What core hole drilling actually involves

Before a new power pole goes in the ground, whether it's a straight replacement for a rotten timber pole or a fresh install for a new private power pole connection, someone has to put a precisely sized hole in the right spot. On most residential jobs in Sydney that means a truck mounted auger, sized to the pole's diameter, boring straight down to the required depth. On tighter sites, such as a narrow side passage or a rear lane block, a smaller trailer mounted or handheld rig may be used instead.

This isn't just "dig a hole and drop the pole in." The hole's diameter, depth and how the pole is backfilled or set are all governed by AS/NZS 3000 and the Service and Installation Rules of NSW, because a private pole has to carry real mechanical load from the overhead conductors above it, plus wind loading, for decades. Getting this step wrong is the single biggest cause of a pole that starts leaning within a few years of being installed, long before its timber, steel or composite structure would normally show signs of age.

2. How deep the hole needs to be

Depth isn't a single number, it's worked out from two things: the free length of the pole above ground (the distance from ground level up to the lowest conductor support) and the soil quality on your block. AS/NZS 3000 and the Service and Installation Rules of NSW both set out a sinking depth table for this (Clause 3.7.2.3 covers private poles specifically), and the depths generally run from around 1.0 metre in good, well compacted soil up to 1.9 metres in poor, soft or waterlogged soil for a typical pole height.

Setting the pole in concrete is treated as improving the soil quality by one full step, so a pole in poor soil that's properly concreted only needs to be sunk as deep as one in medium soil, and a pole in solid rock can have its sinking depth reduced by around 300mm. This is why a Level 2 ASP always assesses the actual soil on your property before quoting a depth rather than using a single generic figure for every job.

3. How wide the hole needs to be

The bore diameter matters just as much as the depth. The rule of thumb used across timber and steel poles is that the hole should be at least 100mm wider than the pole's own diameter, so there's enough room for the pole to sit centred with backfill or concrete packed evenly all the way round. A hole that's too tight won't let the crew centre and plumb the pole properly, and a hole that's too wide wastes concrete and can leave the pole under supported at the base.

Where concrete is used, it needs to be finished below ground level rather than flush with the surface (roughly 250mm to 300mm down for a timber pole, shaped to shed water for a steel one), and left undisturbed for at least three days before any load goes onto the pole. Skipping the cure time is a shortcut some unlicensed operators take, and it's exactly the kind of corner cutting that shows up later as a leaning or shifting pole.

4. What happens when the ground fights back

Sydney's soil isn't uniform, and plenty of Sydney blocks sit on sandstone, made up (filled) ground, or heavy clay that behaves differently to the "textbook" soil categories. A specialist coring rig can bore through sandstone that a standard auger can't touch, which is common in the harbourside and upper North Shore suburbs where power poles regularly go straight through rock shelf.

On the other end of the scale, if your property has soft, poorly compacted or made up ground, and the butt of the pole genuinely can't be sunk to the depth the rules require, an alternative such as flange mounting the pole to a reinforced concrete structure can be used instead, but only with a structural engineer's certification confirming the mounting will safely carry the pole's ongoing load. This isn't a workaround your electrician can decide on their own; it has to be engineered and signed off before construction proceeds.

5. Why the pole material changes the job

Timber, steel and composite poles all drill differently. Timber poles need a slightly more forgiving bore because the base is often shaped and treated against rot and insect attack before it goes in, and the base and surrounding ground need to be treated on site as part of the install. Steel poles are typically galvanised pipe sections and go into a cleaner, more uniform bore since there's no natural taper or grain to account for. Our guide to composite power poles covers why more Sydney homeowners are choosing composite over timber or steel, and the same core hole principles apply, just with a lighter, more corrosion resistant pole going into the ground.

Whatever the material, the crew needs to know the pole's exact diameter before drilling starts, because that number drives both the bore diameter and, in combination with the pole's free length, the depth calculation above.

6. Why this is Level 2 ASP work

Core hole drilling for a private power pole sits squarely inside Level 2 Accredited Service Provider work in NSW, not general electrical or excavation work. A Level 2 ASP is trained and accredited to work on the network side of the connection, which includes the pole, the overhead conductors and the point of attachment, and carries the equipment (truck mounted augers, EWPs, the right sized rigs for tight sites) to do the job to the standard the rules require.

There's also a genuine underground services risk on almost every Sydney block. Before any hole goes in the ground, a Dial Before You Dig check and a visual inspection for existing conduits, pipes or cabling is standard practice, because boring blind into an existing service is a real hazard, not a theoretical one. If your job also involves a defect notice from Ausgrid or Endeavour Energy, our guide on defect notice rectification walks through how that process interacts with pole replacement work.

7. What to expect on the day

A typical core hole and pole set day runs in a predictable order: site assessment and Dial Before You Dig clearance first, then the hole is bored to the confirmed depth and diameter, the pole is lifted into position (usually with an EWP or crane truck depending on pole size and access), plumbed and braced, then backfilled or set in concrete. If concrete is used, no conductors are attached and no load goes onto the pole until the cure time has passed. For a straightforward residential replacement this is usually a single day on site, though concrete cure time means the pole may need bracing overnight before final connection.

If you're also comparing pole types before committing, our guide to private power pole ownership types and rules and the free pole size calculator are both useful starting points before a site visit.

How High Demand Electrical helps

High Demand Electrical is a licensed Level 2 ASP carrying out core hole drilling as part of new private power pole installations, pole replacements and pole straightening jobs across Sydney, not as a standalone excavation service. That means the same crew that assesses your soil, confirms the correct depth and diameter, and bores the hole is also the crew accredited to connect the overhead conductors once it's cured, so there's no handover gap between "the hole is dug" and "the pole is live and compliant."

We carry truck mounted and compact rigs so we can quote the right approach whether your pole is going into open backyard, a tight rear lane, or sandstone that needs specialist coring, and we'll always tell you upfront if council approval is needed for your specific pole before any drilling starts. As one of Sydney's most trusted Level 2 ASPs for private pole work, we're a licensed local team, not a call centre booking out subcontractors sight unseen.

If your existing pole needs straightening rather than full replacement, our power pole straightening guide explains when that's genuinely the right fix instead of a new core hole and pole set. And if you're weighing up removing the pole altogether, our overhead to underground conversion guide covers what that alternative actually costs and involves.

Core Hole Drilling FAQs (Sydney)

Does core hole drilling damage my garden or driveway?

A standard bore leaves a hole roughly the pole's diameter plus 100mm, so the disturbed area is small and localised. Access for the auger or EWP is usually the bigger consideration on tight blocks, and we'll walk you through access requirements during your site assessment.

How long does the concrete need to cure before the pole can be used?

At least three days undisturbed, or longer if needed to reach adequate strength, before any conductor load is attached. This is a minimum, not a target, and rushing it is one of the more common causes of an early leaning pole.

Can an existing pole be reused with a new core hole, or does it need full replacement?

If the pole itself has rot, rust or structural damage, replacement is usually the safer and more cost effective option. See our private power pole replacement guide for how that decision gets made.

Does my new pole need to be labelled?

Yes. A private pole must be clearly marked "PRIVATE POLE" in lettering at least 20mm high, so network crews and inspectors can tell it apart from a distributor owned pole at a glance.

Is core hole drilling different for a Level 2 electrician near me in the inner west versus a standard Sydney block?

The underlying rules are the same across the network area, but rear lane access, sandstone and heritage streetscapes are more common in the inner west. Our sister site's guide to private power poles on inner west terrace and rear lane blocks covers those access and heritage considerations in more depth.

Get a Private Power Pole Quote

Every core hole drilling job starts with a site assessment, because soil quality, access and pole material all change the depth, diameter and equipment needed for your specific job. See our core hole drilling service page, get a private power pole installation quote, or call 0402 559 777 to speak with a licensed Level 2 ASP about your pole. Pricing and exact scope are always confirmed after a site assessment, since ground conditions vary block to block across Sydney.

Core Hole Drilling for Power Poles: How It's Done and Why the Hole Size Matters