Laser level / transit An optical or electronic instrument that projects a perfectly level laser line or references grades to assist in setting precise heights and slopes over long distances.
Establishing correct grades is a technical challenge on NYC sidewalks, which must slope toward the street gutter at a precise pitch (typically 1 inch in 5 feet). Contractors use laser levels and transit levels during the excavation and form-setting stages to ensure the entire sidewalk line maintains a uniform slope. This prevents pooling water, ensures proper drainage, and guarantees compliance with both NYC DOT highway rules and ADA accessibility requirements.
Frequently Asked Questions About Laser level / transit
What is a laser level used for in sidewalk work?
Establishing precise elevations and consistent slope over long distances during excavation and form setting.
Why is precise grade so important?
The sidewalk must drain toward the curb at the specified pitch, commonly around one inch of fall per five feet, without exceeding accessibility limits on cross slope.
What happens without proper grade control?
Ponding water, abrupt changes between new and existing flags, and drainage defects that can be cited.
When in the process is it used?
Before and during form setting, so the forms themselves carry the correct line and grade.