Tie Column Quantity Calculator
Tie column count, concrete, formwork and rebar from wall and section.
Quick answer
With the default inputs: Wall length 20 · Column spacing 4 · Column height 3 etc.Tie columns 6 bars
Edit the inputs below to recalculate.Inputs
Result
Tie columns
6bars
| Section | 576cm² |
| Concrete per column | 0.199m³ |
| Total concrete | 1.19m³ |
| Formwork area | 17.28m² |
| Main bars 4Φ12 | 74.6kg |
| Stirrups Φ6@200 | 19.3kg |
| Total rebar | 93.9kg |
| Steel per m³ | 79kg/m³ |
Assumes 4Φ12 main bars and Φ6 hoops at 200 mm; the design governs. Tie columns are cast after the wall, with 60 mm deep toothings alternating five courses in and out, starting with a setback.
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Formula
| Count | n = floor(wall length ÷ spacing) + 1 |
| Concrete per column | V = section × height × toothing factor |
| Formwork | A = n × 2 × (b + h) × height |
| Main bars | L = n × 4 × (height + 2 × 0.5 m) |
| Stirrup | 2(b−2c) + 2(h−2c) + 2 × 11.9d |
A 20 m wall at 4 m spacing with 240×240 columns 3 m high: 6 columns, 1.19 m³ of concrete, 17.28 m² of formwork and about 93.8 kg of reinforcement — 78 kg per cubic metre.
How to work it out
- Count n = ⌊wall length ÷ spacing⌋ + 1. Spacing is typically 4 m, with columns always at corners, tees and both sides of openings, and wherever the wall exceeds 5 m.
- Concrete per column = width × depth × height × toothing factor. The toothing factor of 1.10-1.15 accounts for the indented keyway that also gets filled.
- Formwork A = n × 2 × (b + h) × height. Only two faces are formed; the other two are the wall.
- Main steel = n × 4 × (height + top and bottom anchorage), each anchorage normally 500 mm.
- Stirrups: length = 2(b − 2c) + 2(h − 2c) + 2 × 11.9d, count = height ÷ spacing + 1.
Where it goes wrong
- Ignoring the toothing — indents 60 mm deep at 300 mm centres add 10-15% concrete over the net section, and omitting them under-reports.
- Forming all four faces — a tie column is formed on two sides only, since the other two are the wall; four faces doubles the formwork.
- Detailing tie columns as load-bearing — they are a confinement measure for masonry, so 4Φ12 with Φ6@200-250 is the point; heavier steel is not better.
Material and cost
C25 concrete about 420 per m³, formwork 55-75 per m² (small areas carry a higher rate), steel around 4,500 per tonne. A 240×240 column 3 m high takes about 0.2 m³, 15 kg of steel and 2.9 m² of formwork — roughly 350-450 each all in.
On site
- Build the wall first and cast the column after; the toothing steps back then forward at 300 mm centres and 60 mm depth.
- Connect the column head positively to the beam or slab with starter bars or resin anchors, or it confines nothing.
- Tighten stirrups to 100 mm within 500 mm of each end — a seismic requirement.
Basis
- GB 50003-2011 Code for design of masonry structures, Sections 6.3 and 10.2 (tie columns)
- GB 50011-2010 Code for seismic design of buildings, Section 7.3 (tie columns in multi-storey masonry)
- GB 50203-2011 Code for acceptance of masonry construction, Chapter 8
FAQ
When are tie columns mandatory?
Common rules: a wall longer than 5 m or twice the storey height needs one at mid-length; over 8 m or 2.5 times the height, add more. Also at unconstrained wall ends, both sides of openings, parapets and stair corners. The purpose is to break long walls into segments so they cannot buckle out of plane.
Why cast the column after the wall?
The column works compositely with the masonry, gripping it through the toothings. Casting first leaves a flat joint relying only on mortar bond with almost no shear capacity — as good as no column at all. The code therefore requires wall first, toothings left, column cast later, with a 50-100 mm gap at the head filled with non-shrink mortar.
How is toothing concrete counted?
Multiply the section by 1.1-1.2. The toothings make the actual section larger than the rectangle — 60 mm deep, five courses in and out, adding roughly 10-20% volume. The precise method is (width + tooth depth) × thickness × height, but the factor is what settlements normally use.
Cite this page
Use this format in reports, method statements or coursework. The link is permanent.
Building Calculator. Tie Column Quantity Calculator. 2026-10-25. https://jianzhujisuan.com/en/tie-column
Results are estimating aids only and are not a design basis. Construction and final accounts must follow the drawings, the applicable standards and an approved method statement. Anything affecting structural safety, shoring or falsework must be checked by a suitably qualified engineer.