Wall concrete = (length × height − openings) × thickness. A 20 m wall, 3 m high and 250 mm thick with 4 m² of openings needs 14.0 m³ (14.7 m³ with 5%). Rising at 1.5 m/h, the pour takes 2 hours, so trucks must arrive at about 7.4 m³ an hour.
Volume = (L × H − openings) × t
Lifts = ⌈H ÷ lift height⌉
Time per lift = lift height ÷ rate of rise
Supply rate = volume per lift ÷ time per lift
Worked example
A wall 20 m long, 3 m high, 250 mm thick, 4 m² of openings, one lift at 1.5 m/h:
- Volume = (60 − 4) × 0.25 = 14.0 m³; with 5% = 14.7 m³
- Time = 3 ÷ 1.5 = 2.0 h
- Supply rate = 14.7 ÷ 2 = 7.4 m³/h, about one 8 m³ truck an hour
- Order 15 m³ → 2 trucks
Concrete per 10 m of wall, 3 m high
| Thickness |
Volume |
| 150 mm |
4.5 m³ |
| 200 mm |
6.0 m³ |
| 250 mm |
7.5 m³ |
| 300 mm |
9.0 m³ |
Frequently Asked Questions
How do I calculate concrete for a wall?
Length × height × thickness, minus doors and windows (opening area × thickness). Add 3–5% for wastage.
Why does the pour rate matter for walls?
The faster concrete rises in the form, the higher the pressure on the formwork. The rate also sets how quickly trucks must arrive. Plan both together.
Should I pour a tall wall in lifts?
Often yes: to limit form pressure, reduce the free fall of concrete and match the formwork height. Each lift ends at a construction joint shown on the drawings.
