Because the ability to repair construction damage to trees is extremely limited, it is vital that trees be protected from injury. The single most important action you can take is to set up construction fences around all of the trees that are to remain. The fences should be placed as far out from the trunks of the trees as possible. As a general guideline, allow 1 foot of space from the trunk for each inch of trunk diameter. The intent is not merely to protect the above ground portions of the trees but also the root systems. Remember that the root systems often extend much farther than the drip line of the trees.
Instruct construction personnel to keep the fenced area clear of building materials, waste, and excess soil. No digging, trenching, or other soil disturbance should be allowed in the fenced area.
Concrete cleanout or mixing areas should be well defined and far from the tree where it will drain onto the root zone. Also brick laying operations near a tree should be carefully monitored or avoided. Concrete or masonry drastically alters the soils PH and will make various nutrients and minerals unavailable. Changing the PH back to proper levels is either very difficult or often impossible.
If at all possible, it is best to allow only one access route on and off the property. All contractors must be instructed where they are permitted to drive and park their vehicles. Sometimes this same access drive can later serve as the route for utility wires, water lines, or the driveway. Specify storage areas for equipment, soil, and construction materials. Limit areas for burning (if permitted) cement washout pits, and construction work zones. These areas should be away from protected trees.