Tree Construction Mitigation
Trees are one of a property owner’s most valuable assets, not only for their aesthetic value, but also for the benefits they provide for shade, soil retention, oxygen, and depending on the type of tree, its fruit. Trees also increase the value of a given property by as much as 25%. Therefore, when construction is planned, care should be taken to preserve as many of the property’s trees as possible.
PROTECTING TREES AT THE CONSTRUCTION SITE
If the construction site is vacant land, the planned building project should take into consideration the location of existing trees to minimize damage to them. If the land is heavily wooded, care should be taken to selectively remove only the trees that are in the way of the project. If possible, removal of only the poorest of the trees is ideal.
If the construction is to be done on occupied land, such as remodels, additions, and the like, special care needs to be taken to avoid damage and death to the existing trees. This can be achieved in several ways, and with the cooperation of all the construction workers.
LOSS OF TREES DUE TO CONSTRUCTION
The loss of trees has a devaluing effect on a property, and has a financial effect on the property owner. If it has been decided that one or more trees must be removed, a professional tree faller must be hired. If a tree is damaged during the construction process, it will be costly to try to repair the damage, or the tree will eventually die, have to be removed and replaced.
CONSTRUCTION DAMAGE TO TREES
The main cause of damage to trees during construction is the cutting of roots. When foundations, trenches for sewer or water lines, or underground utilities, or driveways and curbs are dug, tree roots are frequently cut. Feeder roots lie close to the ground’s surface, often only under about six or eight inches of soil. Loss of these roots curtails the tree’s ability to take in nutrients from the soil, which results in damage, or eventual death of the tree.
When larger roots are cut the tree’s stability is undermined. When a storm blows through, a tree whose large roots have been cut will be likely to blow down, resulting in not only the loss of the tree, but there is the potential for damage to any structures or vehicles on the property, to say nothing of any people who may be in harm’s way.
Another source of damage to trees on a construction site is the driving of heavy equipment back and forth over a tree’s root system. This compacts the earth, causing the root system to suffocate due to the reduction in oxygen in the compressed soil. Trucks can drive too close to the trees and inadvertently hit them, resulting in damage to the bark, or possibly broken limbs. Placing stacks of construction materials on top of a tree’s root system is harmful, too. Again, the weight of the materials will compress the soil, cutting off the roots’ oxygen supply. Remember that chemicals, paint, solvents, oil, and other similar things can pollute the soil and contribute to the damage and demise of trees. Take care to dispose of these things properly.
Construction drought is another possible cause of tree damage. Often, either there is no water hooked up to the property yet, if it is new construction, or the water is turned off so construction can take place on an already occupied site.
PRE-CONSTRUCTION PREVENTION OF TREE DAMAGE
There are a number of steps to be taken before construction begins on a site to protect and preserve the trees on the property. Placing fencing around each tree is a good place to begin. This will call attention to each tree and prevent trucks and workers from coming too close. If necessary, post Off Limits signs on these fences.
To avoid traffic driving over the root system, before the construction actually begins, plan out a route that trucks can use to drive into the site that is far enough away from the trees to protect them. To avoid soil compression, select a place on the construction site that is well away from the trees to stack lumber, bricks, or other building materials. Avoid piling excavated dirt around a tree. Too much dirt on top of a tree’s root system will starve the roots of oxygen and other nutrients; could damage the bark; and cause fungus or rot to form. Try to dig as little as possible on the site. If possible, dig one line for all the utility lines, well away from each tree. This will prevent unnecessary digging that could result in severed roots. If pruning a tree is necessary, try to do as little as possible. Wait until the construction work is complete before planting any new plants or trees. Water and fertilize the trees regularly during the construction time to minimize shock to the trees.
Another method to prevent damage to the trees on the construction site is to include a clause in the contract that specifies if the contractor or his employees damage a tree, they are liable for the damage. This should ensure the construction crew will be careful workers. Be certain to provide for the proper disposal of any chemicals, paint, varnish, and any other potentially toxic liquids used at the construction site. Never wash out cement trucks or mixers on the ground near trees. If roots have become exposed during some phase of construction, be sure to cover them within 15 minutes with burlap or some other covering. With careful planning and the adherence to these guidelines, the property owner should be able to initiate construction on his property, whether it be new construction, or the remodeling of, or an addition to the existing building, with minimal damage to the trees. Enlisting the cooperation of the contractor and construction crew will ensure that the property owner’s wishes are honored. Then, when construction is complete, the trees will still be there to enhance the building project, giving beauty for years to come.