Abstract

GULICK, J. 1986. Solutions to sidewalk problems. Am. Forests 92(5): 12-15.

A sidewalk block heaved upon a tree’s roots is not the tree’s fault, and in many cases, blaming the tree for sidewalk problems is like blaming the bearer of bad news. A raised or cracked block may be an indicator of other contributing factors-heavy clay soils, severe freeze/thaw cycles, poor construction, even improper watering practices. These “non-tree” factors can predispose blocks of concrete to root intrusion. Depending upon locale and climate, only 10-30 percent of all sidewalk failures in most cities are related to trees and tree roots. A common solution to tree-related sidewalk problems is to cut back the roots of the tree. This is usually a temporary remedy that involves removing the unacceptable concrete blocks and cutting the problem root(s) back to a point where the two-inch-thick sidewalk form can be set. It is generally safe to remove any root with a diameter of less than 4 1/2 inches. Away to literally circumvent the drawbacks that go along with extensive root cutting is to use cutouts and bypass walks. This method is inexpensive, and it solves the problem for a longer period of time than cutting roots does. Another solution is to vary construction standards for sidewalks. In certain cases it may be advantageous to pour the concrete to a depth slightly less than conventional standards. It is recommended that a base of cinders be laid under the concrete. Roots tend to follow the path of least resistance, so the cinders will encourage roots to branch out in that area rather than toward the surface. Whichever method or combination of methods you and your professionals decide is best to solve your particular tree/sidewalk conflict, give your tree the benefit of the doubt and do what you can to protect it during sidewalk repair and construction.

• Copyright © 1986, International Society of Arboriculture. All rights reserved.