Root bridging A protective construction technique where a reinforced concrete slab or elevated ramp is built over tree roots to avoid cutting them.
When repairing sidewalks near mature city trees, property owners face a dilemma: cutting major roots can kill the tree, but paving over them will cause the sidewalk to crack again. Root bridging solves this by reinforcing the concrete flag with steel rebar or elevating the grade slightly. This technique satisfies both the DOT and the NYC Parks Department's strict tree preservation rules.
Frequently Asked Questions About Root bridging
What is root bridging?
A construction technique that builds a reinforced or slightly elevated concrete section over tree roots so the roots do not have to be cut.
Why use it instead of cutting roots?
Cutting major roots can destabilize or kill a City tree and is restricted, while paving directly over roots leads to the sidewalk cracking again.
How is it built?
By reinforcing the flag with steel and, where appropriate, raising the grade slightly so the slab spans above the root zone.
Does it need approval?
Work near City trees requires NYC Parks involvement, and the design must also satisfy DOT specifications and accessibility limits on slope.