Exploring a Sidewalk Repair Option that Saves Trees and Money
In urban spaces, the space left for trees are often too small. As a street tree grows, tree roots may cause the nearby sidewalk to lift, especially if the planting area lacks enough soil area or volume to support the tree’s growth. Creating better planting conditions is as important as selecting the “right tree for the right place” to match existing planting conditions for future growth.
When sidewalks are lifted by tree roots, the fix is commonly to remove and repour sidewalks. The construction process can cause major damage to critical roots or the destruction and removal of the tree altogether. This results in a loss of a mature tree, prolonged disruption to pedestrian and street traffic during repair, and high costs.
A viable and cost-effective alternative may be sidewalk grinding.
Other metro Atlanta cities, including Decatur, Brookhaven, and Dunwoody, are reducing costly sidewalk recontruction projects by grinding down uneven sidewalks wherever possible. However, this approach is currently not in use in the City of Atlanta.
Pilot Test at Castleberry Hill
On a block in Castleberry Hill surrounded by Nelson Street and Centennial Olympic Park Drive, the owners of a new business under renovation raised concerns about uneven sidewalks and the removal of several trees was proposed. Residents of Castleberry Point Lofts who live on the same block were concerned that the mature trees that lined their street would be removed and reached out to Trees Atlanta for help replanting trees.
Instead of removing existing mature trees and replanting new trees, the scenario presented a great opportunity for Trees Atlanta to test a more sustainable solution: grinding down the concrete where trip hazards were identified.
The pros of this approach were numerous:
- Mature trees would be preserved
- Cost of sidewalk grinding is a fraction of the cost of reconstructing new walks
- Tree removal and new tree planting expenses eliminated (removal permits would have had to be approved for any removal)
- No traffic disruption and sidewalk closures for nearby businesses and residents
- Reduced repair time — hours instead of days (or weeks)
- Minimal construction debris and no new construction materials used
Watch how it’s done.
The sidewalks surrounding the triangular block between Nelson Street and Centennial Park Drive were repaired in one day: 64 spots were marked, grinded, and cleaned up.
Trees Atlanta and the Castleberry Point Loft homeowners association jointly funded this pilot test to remove trip hazards and save their trees. According to Dorian Hill, Committee Chair of the Architectural Control and Beautification Committee, residents are very pleased with the simplicity of the repairs and, more importantly, that their neighborhood trees were saved.
Design for Trees
Urban spaces can be better designed to plan for trees to grow to maturity, including creating larger planting areas between the street and sidewalk, building larger planting cutouts/wells in sidewalks specifically for trees, or installing devices like “silva cells” or grids that can reduce soil compaction and create space under sidewalks for roots to grow into.
Sidewalk damage should not all be attributed to trees as evidenced by walkways that are failing without any nearby trees. The sidewalk itself should be constructed to prevent uneven settling and cracking regardless of nearby trees.
Additional alternatives for working around trees include bridging over roots, curving sidewalks around large trees, and using pervious pavers.
Thank you to the Castleberry Point Lofts, Georgia Safe Sidewalk (sidewalk grinding contractor), and Natalie Snedden (video footage).
Posted on: July 6, 2022