Find the boundary before you find the saw
The most common cause of an abatement going wrong is that the fence is not the boundary. In the older Illawarra suburbs, fences built and rebuilt over seventy years drift, and on sloping blocks with retaining walls the visible line can be well off the legal one.
Get the deposited plan, check the survey pegs if they are still there, or engage a surveyor for anything significant. Cutting on the wrong side of the line converts a lawful abatement into damage to someone else's property.
Cut where the tree can seal it
Trees do not heal wounds. They compartmentalise them, growing new tissue over the cut from the branch collar — the slight swelling where a branch meets the stem or a larger limb. Cut just outside the collar and the tree closes the wound. Cut flush into the stem and you destroy the collar and open a path for decay straight into the trunk. Leave a long stub and it dies back and rots inward.
On a boundary job that creates an obvious tension: the boundary is where you are allowed to cut, and the branch collar is where the tree needs you to cut, and they are rarely in the same place. The resolution is usually to cut back to a suitable lateral branch or union on your side of the line rather than leaving a bare stub in mid-air. A competent pruning job finds that point.
The three-cut method
Any limb heavy enough to tear needs three cuts, not one.
- An undercut a short distance out from your intended final cut, about a third of the way through from beneath.
- A top cut slightly further out again, which lets the limb fall cleanly — the undercut stops the bark tearing back down the stem.
- The final cut, at the collar or lateral, on the now-weightless stub.
Skip the undercut on a heavy limb and the falling branch strips a long tongue of bark off the trunk. That wound is far worse than the branch ever was, and if it is your neighbour's tree it is a problem you have created.
Stop if any of this is true
You would need a ladder and a chainsaw at the same time. The limb is over a roof, a fence, a car or a power service. The branch is thicker than your thigh. There are power lines anywhere near. The tree is dead, has a torn union or shows decay. You would have to lean, reach or stand on anything not designed to be stood on.
Chainsaw injuries in domestic tree work are overwhelmingly ladder injuries. The economics are also poor: a day in hospital costs more than the job would have.
Do not cross the line
You may cut what overhangs your land. You may not enter their property to do it, and that includes a ladder leaning over the fence, a cherry picker reaching across, and standing on their retaining wall. Ask permission if you need access — most people give it, and asking costs nothing.
Council rules apply to you as well
The right to abate does not override tree preservation controls. If the tree is protected under Wollongong, Shellharbour or Kiama controls, substantial pruning needs approval regardless of which side of the boundary the branch is on. The approval guide covers it, and the service areas page says which council applies.
Then there is the debris
The cuttings are still your neighbour's property. What you may and may not do with them is covered in throwing branches back, and the legal framework is in whose responsibility it is.
For a quote on boundary pruning done properly, ring (02) 4210 5885.
Frequently asked questions
Where exactly is the boundary if the fence is not on it?
The legal boundary is where the survey says it is, and fences are frequently not on it. In older Illawarra suburbs a fence out by 200 to 300 millimetres is common, and on sloping blocks with retaining walls it can be more. If you are cutting anything substantial, work from the deposited plan or get a surveyor. Cutting past the boundary is damage to someone else's tree.
Can I cut roots that come under the fence?
The same right applies to roots as to branches, but it is far more dangerous to the tree and to you. Structural roots near the trunk hold the tree up, and severing them can destabilise it — at which point, if it falls on your house, the question of who caused it becomes very live. Anything thicker than a wrist near a large tree should not be cut without an arborist's assessment.
What if cutting the overhang would kill the tree?
Then you should not do it. The right of abatement does not extend to destroying your neighbour's tree, and a court takes a dim view of abatement carried out so aggressively that the tree dies or becomes unstable. If removing the encroaching portion would take most of the crown, the honest answer is that the situation needs negotiation or an application, not a saw.