Edger A specialized hand tool with a curved lip used to round off the outer edges of a freshly poured concrete slab to prevent chipping and create a clean, finished appearance.
Using an edger is a vital step in finishing a sidewalk flag. Sharp, 90-degree concrete corners are highly fragile and will easily chip or spall when exposed to pedestrian traffic or snowplows. By running an edger along the inside of the wooden formwork, the contractor creates a neat, rounded corner that is far more durable. This detailing also gives the sidewalk the classic, clean picture-frame look expected on NYC walkways.
Frequently Asked Questions About Edger
What does a concrete edger do?
It rounds off the outer edges of a fresh slab, creating a durable, finished corner instead of a sharp square edge.
Why round the edges?
Sharp 90-degree corners chip and spall easily under foot traffic, snow shovels and plows. A rounded edge lasts far longer.
When is edging done?
During finishing, after floating and before or alongside the final texturing, while the concrete is still workable.
Does edging affect appearance?
Yes. It produces the clean framed look expected on NYC sidewalk flags.