Measuring tree height, reach and lean
When planning the felling of a complex tree, you need to consider the tree’s height, diameter, lean, the wind direction and speed and of course the distance to surrounding trees, buildings, overhead power lines, roads and other obstacles. Selecting the right felling direction, felling tools and felling method are crucial for a successful outcome.
The margin of error in advanced felling situations is much smaller than when felling normally. That’s why advanced felling work should only be carried out if you have the correct knowledge and tree felling experience.
How to measure the height and reach of a tree
It is often easy to misjudge the length of trees. Always estimate the tree’s length before felling it, especially in hazardous and confined locations, such as close to other trees, buildings, overhead power lines, etc.
Here is a simple way of estimating how tall a tree is:
Hold a stick with your arm stretched out straight in front of you so that the stick length is equal to the distance between your eye and hand. Hold the stick vertically to create a right-angled isosceles triangle between your eye, hand and the top of the stick.
Point at the tree and stand at a distance so that the tree appears to be as tall as the length of your stick. If the tree is leaning, you get a more accurate estimate if you measure from the side, so that the tree is neither leaning towards you or away from you.
The distance between you and the tree is now equal to the height of the tree. Step out the distance, or measure with a tape measure. Always add a hefty margin of error.
How to measure the lean of a tree
To measure the lean of a tree, you need a plumb line, such as a nut tied to the end of a string.
Aim towards the top of the tree trunk. Note where the plumb line hits the ground.
Measure the distance from the plumb line’s point of impact to the centre of the trunk.
