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

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)

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.

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.

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.

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.