Shade Tree Newsletter

Trees and Sidewalks Fall Newsletter

Creating Harmony between Homeowners, Trees, and Sidewalks

Sidewalk damage can be a stressful and expensive problem for property owners.

The most common solution is removal of a tree, but it may not be the root of the problem. Trees are a valuable community asset and provide many benefits: shading our streets and homes, raising property values, filtering pollutants and neighborhood beautification. Many tree benefits are taken for granted and their loss is often not felt until the tree has been removed. A sidewalk can be repaired quite readily, but the seventy-five years it took for a tree to mature and shade several homes is not easily replaced.

Soil type is often not considered before sidewalks are installed, and heaving initially cracks the sidewalk, providing an opportunity for tree roots. Sidewalk damage from tree roots is also hastened by substandard construction practices. In soils with a high shrink/swell potential, with large nearby trees or previous instances of sidewalk damage, sidewalks need to be constructed more robustly. This can include using a thicker slab (than the commonly used 4 inch slab), using reinforced concrete and laying a well compacted gravel base. Tree roots cannot grow into tightly compacted porous gravel. Although more expensive, these methods will prolong sidewalk life, whether root damage from nearby trees is a concern or not.

Before starting a sidewalk repair or replacement project, be sure to discuss the options with a concrete contractor who understands that the homeowner is responsible for ensuring that tree roots and tree health are not compromised. Township ordinances protect trees and roots from damage and a permit is required prior to the start of sidewalk repair or replacement projects.

Sidewalk Repair Options

  • Install a more narrow or curved sidewalk around the tree. This can be done by curving the sidewalk around the tree to accommodate the trunk and root flare of the tree. A good rule of thumb to follow is to maintain at least 18 inches between the sidewalk and the tree.
  • Replace the sidewalk with a flexible less costly material to replace.
  • Installing removable or semi-adjustable pavers can serve as an easy to fix alternative to concrete.
  • Install a root barrier to deflect the roots downward underneath the sidewalk.
  • Patch the sidewalk, creating a ramp up to the lifted slab.
  • Grind the edge of the lifted slab, reducing the height difference between the two adjacent slabs.