The time to protect mature trees on your property from damage during a house remodel (if you decide to save the trees), is before construction starts. Otherwise, you could end up paying many thousands of dollars to replace trees that are injured or killed by heavy machinery or other mishaps.
When roots are compacted by heavy equipment or severed by trenching, chances are you won’t see the damage immediately. But injured roots are often unable to take up water, air or nutrients, and this results in the decline and eventual death of the tree, even years later. Disease organisms or pest infestations that enter unhealed wounds can also kill the tree in time.
Avoid building within the root zone of a large, established tree. Allow at least one foot of space between the trunk and the structure for every inch of trunk diameter measured at 54 inches above soil level. Learn where any new underground lines will go and reroute them away from trees, if possible. If it’s not possible for contractors to work outside the root zone, up to one-third of a healthy tree’s roots can be removed without severely harming the tree, but its growth and health may be set back for years.
If heavy equipment must be moved over the root zone, cover the area from the trunk out to the drip line with a 12-inch-thick layer of wood chips, then top the mulch with sheet metal plates or plywood sheets to minimize soil compaction. Make sure your contractor knows your wishes regarding your trees and will convey your wishes to workers; the best way to do that is to spell them out in the remodeling contract.
If you do sustain some damage to any of your mature trees, here are some tips you