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Trees: 10 Things That Go Wrong on Building Sites

Trees get damaged on building sites more than they should. It doesn't have to be this way.

Managing trees on a building site is usually pretty simple. It just takes some planning and a little bit of buy in.

Doing it right should be simple but too often it goes wrong.

Protecting trees on a construction site means understanding that there is more than stem branches and leaves. It’s all about the roots.

Here’s a list of 10 things that often go wrong

Diameter at Breast Height x 6

1) Underestimating the Critical Root Zone

Protecting a tree is requires protecting its roots. The concept is called the critical root zone. The bigger the tree the bigger the critical root zone.

A rule of thumb is the dripline. The going standard in our area is the simple formula

DBH x 6 = Critical Root Zone

(DBH is diameter at breast height)

excavation unplanned is unsuccessful

2) Failure to anticipate the excavation.

Typically the excavation is about 1.5m (5 feet) beyond the actual building footprint.

That can mean a large portion of critical roots is gone if the excavation zone wasn’t considerred in the planning.

neighbours don't when their tree gets wrecked

3) Failure to consider neighbours trees.

People understand fences and boundaries. Tree roots do not understand fences and boudaries. This can turn into big problems if we go and dig up the roots of the neighbours tree.

The bigger the tree the bigger the problems.

sewerage, better out than in the crz

4) Failure to plan underground services

Out of sight out of mind. Often services such as gas, water, storm, electrical, and sanitary are located in conflict with trees. If the conflict is considered early in the process then decisions can be made, roots are spared and trees are saved.

When you leave the services planning to the last minute the tree loses.

how to kill a tree 101

5) Grade alterations around the tree.

The excavation is done and the underground services are in. Now attention turns to the landscape. One of the best ways to kill a tree is by adding or subtracting large amounts of soil volume from its root zone.

Do not pile soil around a tree.

nothing like a good solid fence through the roots

6) Failure to plan the hardscapes.

The trend in landscape design these days seems to be these concrete or brick walls that surround the property. Roots be damned.

and they complain that it cracks

7) Failure to plan driveways.

Asphalt is a wonderful material for creating a firm, smooth surface upon which to drive or park a car. As an added feature it vastly reduces the transference of water, air and nutrients to roots.

Not the best way of doing it.

hire a decent landscaper

8) Damage caused by digging machines around the job.

Mini excavators and skid steer digging machines are astonishingly productive little creatures when used well.

They are incredibly destructive when working for the dark side.

use a sharp saw instead of a dull bucket

just so many creative ways to kill a tree

9) Failure to use the right tools for the job.

Why bother pruning a root with a sharp saw or loppers when a blunt and powerful bucket of an excavator is perfectly capable of the task.

10) The tree protection area as a dumping ground.

If you’ve ever been curious about the effects a mixture of paint, drywall compound and neat cement can have on a tree a study in underway. I would invite you to come observe this tree but unfortunately it is no longer with us.

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