How Deep Should Electrical Cable Be Buried? | Brisbane Guide

Underground Cable Depth Requirements for Brisbane Homes and Properties

Burying electrical cables is common for outdoor lighting, shed power, pool equipment, garden features and granny flat connections. But getting the depth wrong can be dangerous — cables that are too shallow can be struck by garden tools, tree roots or vehicles, creating electrocution and fire risks. For property owners across North Lakes, Redcliffe, Mango Hill, Chermside and Aspley, here are the requirements.

Minimum Burial Depths (AS/NZS 3000)

What Type of Cable Is Used Underground?

Underground cables must be specifically rated for direct burial or installed in conduit. Common types include:

• Orange circular cable (for direct burial in residential applications)
• Armoured cable (for higher protection requirements)
• Standard cable in heavy-duty conduit (grey or orange electrical conduit)

Standard domestic cable (TPS/flat cable) must not be buried directly — it must be run through conduit if used underground.

Installation Requirements

1. Conduit Protection

Even when using direct-burial rated cable, conduit provides additional mechanical protection and makes future cable replacement easier. Heavy-duty conduit is required under driveways and vehicle areas.

2. Warning Tape

Yellow warning tape must be laid in the trench approximately 150mm above the cable to alert anyone digging in the area that electrical cables are below.

3. Sand Bedding

Cables should be laid on a bed of clean sand (minimum 75mm) and covered with sand before backfilling with soil. This protects the cable from sharp rocks and provides a stable base.

4. Circuit Protection

Underground circuits must be protected by a safety switch (RCD) at the switchboard. Surge protection is also recommended for outdoor circuits exposed to lightning risk.

Common Underground Cable Projects

Why This Must Be Done by a Licensed Electrician

Underground electrical work involves mains voltage, trenching near existing services (water, gas, data) and compliance with AS/NZS 3000. Incorrect installation creates hidden hazards that can cause electrocution or fire years later. A licensed electrician will also call Dial Before You Dig to locate existing underground services before trenching.

Areas We Service Across Brisbane and North Brisbane

Connex Electrical provides expert electrical services across Brisbane and North Brisbane, including:

• North Lakes
• Redcliffe
• Mango Hill
• Griffin
• Kallangur
• Burpengary
• Morayfield
• Caboolture
• Chermside
• Aspley
• Everton Park
• Stafford
• Wavell Heights
• Murrumba Downs
• Rothwell
• Deception Bay
• Petrie
• Lawnton
• Strathpine
• Brendale
• Albany Creek
• Eatons Hill
• Warner

Our Full Range of Electrical Services

• Switchboard Upgrades
• Emergency Electrician
• Air Conditioning Installation
• Electrical Safety Inspections
• Surge Protection
• EV Charger Installation
• LED Lighting Installation
• Ceiling Fan Installation
• Smoke Alarm Installation
• Powerpoint Installation
• Residential Electrician
• Commercial Electrician
• Data Cabling

Need Underground Electrical Work?

Connex Electrical installs underground cables for sheds, granny flats, pools, outdoor lighting and EV chargers across North Brisbane.

Call 0474 207 609 or visit our contact page to book.

Frequently Asked Questions

How deep do electrical cables need to be buried in Australia?

Standard residential underground cables must be buried at least 500mm deep under lawn or garden areas, as specified in AS/NZS 3000.

Can I bury standard electrical cable?

No. Standard TPS cable must be run through conduit if used underground. Direct-burial rated cable or armoured cable can be buried directly.

How much does it cost to run power to a shed?

Running underground power to a garden shed typically costs $800 to $2,000 depending on distance and circuit requirements.

Do I need a licensed electrician for underground cable?

Yes. All underground electrical work must be performed by a licensed electrician and comply with AS/NZS 3000.

What is the warning tape for in underground cable trenches?

Yellow warning tape is laid 150mm above the cable to alert anyone digging that electrical cables are below, preventing accidental damage.