Read this before the technique
The technique below is genuine and it is how trees are felled. It is also, in a suburban setting, almost never the right method, and if you have arrived here looking for permission to drop a tree in your back yard, the more useful page is what you can safely do yourself.
With that said, here is how a felling cut works and what each part of it controls.
The three cuts
The notch, or scarf. A wedge cut into the side of the trunk facing the intended fall direction. It is made with two cuts that meet cleanly — typically a horizontal cut and an angled cut down to meet it — and it is usually a fifth to a quarter of the trunk diameter deep. The notch sets the direction. A notch whose two faces do not meet cleanly, or that is aimed slightly off, produces a tree that falls slightly off, and slightly off over twenty-five metres is several metres of error.
The hinge. The uncut band of wood between the back of the notch and the back cut. This is the part that does the work. It holds the falling stem to the stump, steers it along the line the notch set, and controls the rate of fall. It should be roughly a tenth of the trunk diameter thick and consistent all the way across. Cut through it at any point and the tree is no longer attached to anything and no longer steered.
The back cut. Made from the opposite side, slightly above the base of the notch, stopping short of the hinge. As it opens, the tree begins to move and the hinge takes over.
Wedges driven into the back cut prevent the saw being pinched and help push a tree that is leaning slightly the wrong way. They are not a way to fell a tree that is leaning substantially the wrong way.
What goes wrong
The hinge cut through, so the tree goes where the lean and the wind send it. The back cut made below the notch, which can cause the stem to kick backwards off the stump. A hinge thicker on one side, which swings the tree off line. Wind picking up between the notch and the back cut. A dead limb dropping out of the crown as the tree starts to move. Barber-chairing, where a stem under tension splits vertically and rears back, which is fast and frequently fatal.
None of these are exotic. They are the ordinary failure modes, and they are why felling is taught with escape routes cleared before the saw starts.
Why the Illawarra uses sections instead
Felling needs a drop zone. Two tree lengths, clear, with nothing in it worth anything. A forty-metre blackbutt behind a house in Figtree would need eighty metres of empty ground to fall into, and there is no such ground anywhere in the suburb.
So the tree comes apart instead. A climber ascends on rope, removes the crown in manageable sections, and each piece is attached to a rigging line and lowered under control rather than allowed to fall. The stem is then cut down in blocks, each one lowered or dropped into a small prepared area at the base.
It is slower, it costs more, and it puts the material exactly where it is meant to go. Where even that is impractical — no access to carry it out, or a tree too decayed to climb — a crane lifts sections over the roof to the street. The cost guide explains where that decision sits, and the removal page covers the method.
Before any of it
Check whether the tree is protected. Council approval applies to your own trees on your own land, and doing the work yourself does not change that.
Ring (02) 4210 5885 if the drop zone does not exist.
Frequently asked questions
What does the hinge actually do?
It steers the tree. The strip of uncut wood left between the notch and the back cut acts as a hinge that holds the stem to the stump while it falls, controlling the direction and slowing the fall. Cut through it and the tree is free to go anywhere, including backwards or sideways. Almost every felling that goes badly wrong involves a hinge that was cut through or made uneven.
How wide should the notch be?
A common guide is a notch depth of about a fifth to a quarter of the trunk diameter, with a hinge left about a tenth of the diameter thick and consistent across its width. The exact figures vary with species, lean and technique. What matters more than the numbers is that the notch faces exactly where you want the tree to go and the hinge is even.
Why do professionals rarely fell trees whole in the suburbs?
Because there is nowhere to put them. Felling needs a clear drop zone two tree lengths long and free of anything valuable, and almost no suburban block in the Illawarra has one. Sectional dismantling — climbing the tree and lowering it in pieces on ropes — puts the material exactly where it needs to go instead of hoping the fall goes as planned.