Rebar Tie-Wire Count and Weight
Tie wire for a rebar mat - the intersections tied and the wire consumed.
Example
You enter
- Mat length (ft) 30
- Mat width (ft) 20
- Bar spacing each way (in) 12
- Fraction of intersections tied (0-1) 0.5
- Wire per tie (in) 8
- Tie wire weight (lb/ft, ~0.0181 for 16.5 ga) 0.0181
You get
- Intersections 651
- Ties 326
- Wire (lb) 3.934
Details, formula, and sources
bars each way = floor(span / spacing) + 1; intersections = product; ties = round(intersections x fraction); weight = ties x tie length / 12 x wire per foot. A 30 x 20 ft mat of #4 at 12 in each way has 651 intersections; tying half with 8 in ties is ~3.9 lb of wire, and a full-tie spec nearly doubles it to 7.9 lb. The spec sets the tie fraction; distinct from the bar weight takeoff.
bars_each_way = floor(span_in / spacing_in) + 1; intersections = bars_x x bars_y; ties = round(intersections x tie_fraction); wire_ft = ties x tie_length_in / 12; wire_lb = wire_ft x wire_lb_per_ft.
Rebar tie-wire identity by name (grid intersections, a tied fraction, and the wire per tie); first-principles count arithmetic.
The intersection-count geometry is public first-principles; the tie fraction and wire gauge come from the spec and CRSI practice.
Estimate. AHJ and licensed professional govern.
Field names used by the API: length_ft, width_ft, spacing_in, tie_fraction, tie_length_in, wire_lb_per_ft, intersections, ties, wire_lb
- Tie fraction perimeter fully tied, ~50% in the field per CRSI practice; the spec governsCRSI / project spec
- Wire ~8 in per tie, ~0.0181 lb/ft for 16.5 ga annealed tie wiretie-wire gauge