Root barrier / root deflector A subterranean plastic or fiberglass shield installed vertically alongside a sidewalk flag to redirect tree roots downward and away from the concrete pavement.
To protect a newly poured concrete sidewalk from future root damage, contractors often install root barriers along the edge of the tree pit. These durable sheets prevent roots from growing horizontally directly beneath the sidewalk slab. In NYC, incorporating root deflectors into a sidewalk replacement project is an excellent preventive strategy that complies with Parks Department guidelines, safeguarding both the health of the street tree and the long-term flatness of your walk.
Frequently Asked Questions About Root barrier / root deflector
What is a root barrier?
A subsurface plastic or fiberglass panel installed vertically beside a sidewalk to redirect tree roots downward and away from the concrete.
When is one installed?
Usually during a sidewalk replacement near a street tree, along the tree pit edge, as preventive protection for the new slab.
Does it harm the tree?
Properly installed barriers redirect rather than sever roots, which is why placement and depth should follow arborist and Parks guidance.
How effective are they?
They reduce shallow lateral root growth beneath the slab, which is the main cause of heaving, though they do not eliminate all root activity.