Avoiding Tree Damage During Construction On Your Home
Trees and Construction: how to avoid damage to your trees while doing construction on your property.
It is important to preserve the health and structural integrity of trees when doing construction because construction activities can pose a significant risk to them. Common threats to trees on or near construction sites include root damage, soil compaction, changes in soil grade, physical damage to trunk or branches, and exposure of roots to pollutants, soil compaction, plastics, construction chemicals, and construction equipment.
Common threats
- Soil compaction: The weight of excavators, bulldozers, dump trucks, and repeated foot traffic all compress the soil around tree roots. This greatly reduces the amount of oxygen that reaches the roots and inhibits water infiltration, which can suffocate tree roots.
- Root damage: Lot clearing and excavation, trenching, and grading are all things that can cut or crush roots. When roots are damaged, the tree cannot absorb the water and nutrients that it needs to survive.
- Soil grade changes: When dirt is added or removed from around the base of a tree, roots can be buried or exposed. This can stress the tree or cause irreversible damage.
- Physical damage: The side of an excavator or bulldozer can scrape or bruise the bark of a tree. When this occurs, the protective outer layer of the tree, the bark, is damaged, and it can allow diseases and pests to invade.
- Chemical exposure: Spills of concrete and fuel, and other construction chemicals can negatively impact tree root systems and the health of surrounding soil.
How to Protect Trees During Construction:
- Set up a tree protection zone (TPZ): Install a fence around the tree’s dripline or greater if achievable. The purpose of the tree protection zone is to keep machinery, equipment, and foot traffic out of the zone, which allows for soil compaction and root damage in this area to be limited.
- Avoid disturbing tree roots: When working in the TPZ, aim to limit excavation and trenching activities. Furthermore, if you need to cut tree roots, do it cleanly with the appropriate tools and consider having an arborist inspect the cut roots and then provide input about the area of root disturbance.
- Maintain soil grade: Avoid piling materials and soil on top of areas with roots, and maintain the native soil grade around the tree as a general practice to help avoid tree suffocation or root exposure.
- Protect tree trunks and branches: Partially or fully enclose the trunk area and areas of the canopy with protective barriers or padded surfaces to protect the bark from equipment or vehicular strikes and damage.
- Determine any intended irrigation and mulching plan: If trees do not have access to irrigation during the construction, determine how trees can receive additional watering. If possible, plan for supplemental irrigation, and note that mulching on a regular basis will be required to protect tree roots and maintain soil moisture.
- Utilize an arborist: You may bring in an arborist to the discussions about site development, and possibly even before a contractor starts construction on the site. An arborist may add additional concerns and suggestions to the overall construction plan, and can, if required, work with the general contractor during any construction on site.
Be sure to try to incorporate these suggestions if there is a plan to develop or improve the area surrounding significant trees. When combined, these practices will work to avoid or greatly reduce construction stresses to trees and allow them to remain healthy and vigorous for many years to come.
