Binding wire is a tiny part of the steel budget, but running out of it stops the bar benders, and a poorly tied cage shifts when concrete is poured on it.
How Much Do You Need?
| Steel order | Binding wire (8–12 kg per tonne) |
|---|---|
| 1 tonne | 8 – 12 kg |
| 4 tonnes (≈1,000 sq ft house) | 32 – 48 kg |
| 10 tonnes (≈2,400 sq ft G+1) | 80 – 120 kg |
Small-diameter, closely spaced steel — slabs and stirrups — has more junctions per tonne and uses more wire than heavy column bars.
Which Wire?
- Annealed mild steel wire, soft enough to twist tightly without snapping.
- About 18 or 20 gauge for typical house reinforcement.
- Galvanised wire where extra corrosion resistance is wanted near the concrete surface.
How Is It Used?
| Junction | Tying practice |
|---|---|
| Stirrups to main bars | Every intersection |
| Column ties to vertical bars | Every intersection |
| Slab mesh | Alternate junctions inside, every junction at edges (as specified) |
| Laps | Tied at both ends and along the lap |
| Cover blocks and chairs | Tied to the steel so they do not shift |
Twist the ends inward, away from the formwork, so wire tails do not reach the concrete surface and rust through.
Why It Matters
Binding wire is not structural, but the structure depends on bars being where the drawing puts them. A loosely tied cage can shift when concrete is dropped or vibrated, reducing cover on one side or moving top bars down — problems no one sees until the concrete is cast.
The Short Version
Budget 8–12 kg of annealed 18–20 gauge wire per tonne of steel, tie every stirrup and lap, turn the ends inward, and keep a spare roll on site.
