How to Use a Chainsaw on Trees Safely and Correctly

Using a chainsaw on trees is one of the more hazardous DIY tasks a homeowner can take on. Done correctly — with the right protective gear, a well-maintained saw, and sound technique — it can be manageable for straightforward jobs like cutting up a fallen log. Done poorly, it can result in serious injury or death. This guide covers the fundamentals, but if you have any doubt about the job, please call a qualified arborist.

Know the Risks Before You Start

Chainsaws are responsible for a significant number of serious injuries in New Zealand each year. WorkSafe NZ classifies chainsaw work as high-risk, and for good reason — kickback, falling limbs, and loss of control can happen in a split second. Before you even start the engine, honestly assess whether the job is within your skill level.

As a general rule:

• Felling standing trees (especially anything over 3–4 metres, near structures, or on a slope) should be left to a professional arborist.
• Cutting up a fallen tree or log on the ground is more manageable for a careful, prepared homeowner.
• Pruning large limbs overhead is best left to a qualified arborist with the right rigging equipment.

Essential Personal Protective Equipment (PPE)

Never operate a chainsaw without the correct PPE. This is non-negotiable:

You can find suitable PPE at Bunnings or Mitre 10. Do not substitute standard work gloves or regular trousers — chainsaw-specific PPE is designed to jam the chain on contact, potentially saving a limb.

Chainsaw Maintenance and Pre-Start Checks

A poorly maintained chainsaw is a dangerous chainsaw. Before every use:

• Check the chain tension — a loose chain can derail and cause injury. The chain should snap back firmly when pulled away from the bar.
• Inspect the chain sharpness — a sharp chain cuts smoothly with minimal pressure. A blunt chain causes you to force the saw, increasing kickback risk.
• Check the chain brake — push the saw forward and ensure the brake engages. Never use a saw with a faulty chain brake.
• Check bar oil and fuel levels — the bar and chain must be lubricated throughout cutting.
• Inspect for damage — cracks in the bar, damaged sprocket, or loose components mean the saw should not be used.

Safe Cutting Techniques

Body Position and Grip

Always hold the saw with both hands, thumbs wrapped around the handles. Stand to the side of the cutting line, never directly behind the saw. Keep your feet shoulder-width apart and maintain a stable stance.

Understanding Kickback

Kickback is the sudden upward and backward rotation of the saw, usually caused by the tip of the bar contacting an object. It is the leading cause of chainsaw injuries. To minimise kickback risk:

• Never cut with the tip of the bar.
• Keep the chain sharp and properly tensioned.
• Engage the chain brake when moving between cuts.
• Use a saw with a low-kickback chain and guard.

Cutting a Log on the Ground (Bucking)

• Identify which way the log is supported — cutting from the top (overbuck) or bottom (underbuck) depends on where the tension is, to avoid pinching the bar.
• If the log is supported at both ends, begin with an overbuck cut of about one-third depth, then finish from below.
• If supported in the middle, begin from below, then finish from above.
• Keep bystanders well clear — at least two tree-lengths away when felling, and a safe distance during any chainsaw work.

Felling a Small Tree

If you are confident the tree is small, clear of structures, and you have a safe escape route, basic felling involves:

1. Plan your escape routes — two clear paths at 45° behind you, away from the intended fall direction.
2. Make a notch cut (open-face cut) on the side facing the intended fall direction — roughly 70° opening, to about one-quarter of the trunk diameter.
3. Make the back cut on the opposite side, slightly above the base of the notch, leaving a hinge of uncut wood to guide the fall.
4. Retreat immediately along your escape route as the tree begins to fall — never watch it fall from behind the saw.

For anything more complex — leaning trees, trees near fences, power lines, or structures — stop and call a professional.

NZ Regulations and Tree Removal Rules

Before removing any tree, check with your local council. Many councils have rules protecting certain trees through district plan provisions or notable tree schedules, and removal without consent can result in significant fines. Some tree work may also require a building consent — check with MBIE Building Performance or your council if you are unsure. BRANZ also provides useful guidance on working safely around structures.

When to Call a Professional

Call a qualified arborist if:

• The tree is near power lines (always — contact your lines company first).
• The tree is large, leaning, or structurally compromised.
• The work involves climbing or working at height.
• The tree is close to your home, fences, or neighbouring property.
• You are unsure about any aspect of the job.

A professional arborist has the training, equipment, and insurance to handle complex tree work safely. You can find qualified local arborists on tradedirectory.co.nz.

Sources & Further Reading

• WorkSafe NZ – Chainsaw Safety
• BRANZ – Safe Work Practices
• MBIE Building Performance – Building Consent Information
• Bunnings – Chainsaw PPE and Equipment
• Mitre 10 – Outdoor Power Equipment