Building Around Trees
How to Protect Trees During Construction
Are we just lucky if trees survive construction? Not at all. We can greatly increase the chances of keeping trees healthy by using these strategies:
Survey the entire construction site well before work begins to determine where trees are and what condition they are in. It is best to plot all trees on a scaled drawing, but this also can be done on the ground, especially for small construction projects. Healthy, vigorous trees with solid stems and a full complement of live branches are the best candidates for saving. Large, old trees may not tolerate much disturbance. Don't overlook smaller, understory trees, such as dogwood, redbud, serviceberry and ironwood. If you are working with builders, inform them of your desire to save trees.
Develop a construction plan that blends the buildings with the trees on the site. This is the time to decide which trees will be removed and which will remain. Consider alternate locations for footings, walks, drives and changes in the ground line to save the best trees.
Keep in mind that it may be necessary to remove some good trees simply because there is not sufficient space for them. It is much easier to make these choices before the construction work begins. The plan can be drafted on a layer that overlays the survey plan, or mark the ground with stakes or flags. Remember that you need to keep a relatively large undisturbed area around each tree to help protect it. The larger the tree, the larger the area needed surrounding it.
Establish tree protection zones around individual trees or groups of trees to be saved. Exclude any type of construction disturbance, including grade changes, vehicle parking or storage of materials around protected trees. Set steel fence posts with flexible, snowfence-type fabric around the perimeter of each protection zone.
Route trenches as far away from trees as possible. Utilities that may require trenching include sanitary sewer, water, gas, electricity and telephone or television cable. Some utilities may be advantageously placed in the same trench. Placement of some utilities is flexible, while others are not. If a trench cannot be placed by the builder to avoid coming close to a valuable tree, consider going under it. Dig the trench directly up to a tree trunk on both sides. Then bore or force a tube or line through the soil below the tree. Rerouting or tunneling for utilities may