Life of an Urban Tree #4 - Construction Damage & its Effect on Trees

Summer is a peak time for renovations and construction in our towns and rural areas. While it is important for municipalities to upgrade our streets and highways, as well as for home owners and builders to improve existing building and amenities this activity can have a major impact on trees. Since trees play such an important role in our health and well being it is helpful to educate ourselves on how we can help preserve our urban forest.

Experts agree that tree protection during construction is more important (and less expensive) than removing damaged trees or planting new ones after the fact.

Root damage on a Honey Locust from sidewalk construction

Construction activities that can damage trees include:

building additions
pool installation
driveway paving
foundation excavation
other landscaping
municipal construction like road widening and sidewalk installations

Construction Damage or Mechanical Damage

Types of tree damage caused by construction:

compaction
scraping bark
breaking of branches
trenching/digging up roots
piling of soil on roots
grade change

Compaction from cars or heavy equipment being parked on roots or from piles of soil being stored on the root zone can suffocate the roots below. For more info on root health check out our blog article on Soil at: https://treecanada.ca/resources/canadian-urban-forest-compendium/13-tree-protection-during-construction-trees-and-building-foundations/

Scraping bark and Broken branches can leave wounds that can lead to decay or invite insect infestation into the tree. Structural damage caused by construction can lead to further breakage in storms if not corrected with proper pruning techniques.

Trenching, grade changes and digging up roots has a significant impact on the health of a tree. It is important to note that trees typically don’t show signs of stress for a few years after root damage has occurred. That is why prevention of damage before it happens is so important!

So what can we do?

We all play a part in preserving our trees and the value that they provide to our everyday lives!
Here is how to protect against construction damage:

Don’t pile materials on tree roots zones. The area directly under the crown of the tree/dripline is the most important area to protect.
Use tree protection on construction sites like fencing or hording to prevent materials, equipment and vehicles from getting too close.
If digging occurs in the root zone of a tree, try to keep back as far as possible from the tree. If roots are exposed, use a sharp saw to cut them so that they can heal easier than if they are torn or ripped
Have pruning done to give clearance before heavy equipment comes in
Grade changes can kill trees, so be aware of that impact

For more information on this topic, please refer to:
https://treecanada.ca/resources/canadian-urban-forest-compendium/13-tree-protection-during-construction-trees-and-building-foundations/