Can I Demolish a Small Brick Garden Wall with a Hired Jackhammer?

Yes, in most cases a capable DIYer can demolish a small freestanding brick garden wall using a hired jackhammer — but before you fire up the machine, there are a few important checks around building consent, safety, and technique that could save you a lot of trouble.

Do You Need a Building Consent?

This is the first question to answer before anything else. In New Zealand, many minor demolition jobs on small garden structures are exempt from building consent under Schedule 1 of the Building Act 2004, but the rules have conditions. Generally, a low freestanding garden wall that is not part of a building's structure, not retaining soil, and not connected to any services may fall under an exemption — but this is not guaranteed.

Key things to check:

• Is the wall retaining soil or acting as a retaining structure? If so, consent rules are different.
• Is it attached to your house or another consented structure? Attached walls may be considered part of the building.
• Is it on or near a boundary? Some councils have specific rules.
• Are there any services running through or near it? Underground pipes, electrical conduits, or gas lines nearby change everything.

Always confirm with your local council before starting. You can also find general guidance at MBIE Building Performance, which outlines Schedule 1 exemptions and when consent is required.

Check for Underground Services First

Before any digging or breaking work, you must locate underground services. Striking a buried electrical cable, gas line, or water pipe with a jackhammer is extremely dangerous and potentially fatal.

• Contact Dial Before You Dig (0800 248 344) or visit their website to request a service location.
• Check with your local council for any drainage or stormwater pipes in the area.
• Look for any conduits or pipes running into or along the base of the wall.

If you find services nearby, stop and get advice from a licensed tradesperson before proceeding.

Safety Gear — Non-Negotiable

A jackhammer is a powerful piece of equipment and brick demolition throws up sharp debris, dust, and noise. WorkSafe NZ sets out clear expectations for safe work, even for DIY projects. You'll need:

• Safety glasses or goggles (flying brick chips are a serious eye hazard)
• Hearing protection (jackhammers exceed safe noise levels quickly)
• Dust mask rated P2 or better — old brick mortar may contain silica dust, which causes serious lung disease with repeated exposure
• Steel-capped boots
• Heavy-duty gloves
• Long sleeves and trousers

Old brick walls — particularly those built before the 1980s — may also contain asbestos in the mortar or render. If you're unsure of the wall's age or materials, have a sample tested before breaking anything. WorkSafe NZ has guidance on identifying and managing asbestos safely.

Hiring the Right Jackhammer

For a garden wall, you typically won't need the largest demolition hammer available. A medium-duty electric demolition hammer (15–25 kg class) with a chisel or moil point bit is usually sufficient for brick and mortar. Petrol-powered units are more powerful but generate exhaust fumes — keep ventilation in mind.

Hire centres at Bunnings or Mitre 10 can advise on the right machine for your job. Always ask for a demonstration and read the operator manual before use.

How to Demolish the Wall Safely

Follow this general sequence:

1. Clear the area — remove any plants, furniture, or objects within a safe radius. Keep bystanders and children well away.
2. Work from the top down — never undercut a wall from the base; it can collapse unpredictably.
3. Break mortar joints first — targeting the mortar between bricks (rather than the bricks themselves) makes the job easier and produces more reusable bricks if you want to keep them.
4. Work in short bursts — jackhammers cause significant vibration; take regular breaks to reduce hand-arm vibration fatigue.
5. Wet the surface lightly — this helps suppress dust, particularly silica dust from mortar.
6. Stack and remove rubble as you go — don't let debris pile up around your feet.

Disposing of the Rubble

Brick and concrete rubble is classified as inert fill in most cases, but you still need to dispose of it responsibly:

• Many local transfer stations accept clean brick rubble — check with your council for drop-off options and any fees.
• Some landscaping suppliers will accept clean brick for reuse or recycling.
• If the wall had any render or coating that could contain asbestos, the rubble must be treated as hazardous waste and disposed of through a licensed facility.

When to Call a Professional

There are situations where hiring a qualified demolition contractor is the smarter — and sometimes legally required — choice:

• The wall is retaining soil or is a structural element.
• You suspect asbestos in the mortar, render, or any coatings.
• The wall is attached to your home or another building.
• Underground services are close to the work area.
• The wall is large, tall, or unstable and could collapse unpredictably.
• You simply aren't comfortable operating heavy equipment safely.

A licensed demolition contractor will have the right equipment, insurance, and knowledge to handle complications safely. You can find qualified local demolition contractors on tradedirectory.co.nz.

Sources & Further Reading

• MBIE Building Performance — Building Consent Exemptions
• WorkSafe NZ — Silica Dust and Asbestos Safety
• BRANZ — Demolition and Deconstruction Guidance
• Bunnings NZ — Tool Hire
• Mitre 10 NZ — Tool Hire
• Standards NZ — NZS 3604 and Related Building Standards