The Three Numbers Behind Every Load Count
Every truck count starts with the same three numbers.
- Bank volume. Pad length × width × average cut depth, in metres. That's the hole in the ground, measured as the soil sits before it's dug, and it's usually the figure on your drawings.
- Swell. Clay takes up more room once it's loose in a tray. On western Melbourne clay we work on about 1.3, so every 10 m³ in the ground becomes about 13 m³ on the truck.
- Load size. On clay we plan around 8 m³ of loose spoil per tipper load. Lighter fill can run closer to 10 m³. Tight access or a smaller truck can drop it to around 6 m³.
Loads = bank volume × 1.3 ÷ load size, rounded up. A part-load still needs a truck.
Three Melton Examples
These are typical shapes of job around Melton, Rockbank, Aintree and Kurunjang. Use them as a sense-check, not a quote.
| Job | Cut | Bank m³ | Loose m³ | Loads at 8 m³ |
|---|---|---|---|---|
| Flat estate lot, detailed cut | 18 × 12 m × 300 mm | ~65 | ~84 | ~11 |
| Bigger house, gentle fall | 20 × 15 m × 450 mm | ~135 | ~176 | ~22 |
| Sloping block, cut side only | 22 × 7 m × 900 mm | ~139 | ~180 | ~23 |
Flat estate lot
Many estate lots around Aintree and Fraser Rise are handed over well graded, so the cut is shallow: a few hundred millimetres to get under the topsoil and down to pad level. Around ten to a dozen loads is common. On a job this size, access and the tip run often matter more to the price than the volume.
Bigger house, gentle fall
A bigger footprint and a bit of fall across the lot double the volume quickly. Twenty-odd loads is a full day of trucks, so we plan the run order and where trucks wait before the excavator starts.
Sloping block
On a block with real fall, only part of the pad is cut and the low side may be filled. If the engineer allows the cut material to be reused as fill, some of those loads never leave the block. If not, because the clay is too wet or the material is wrong, every one of them goes on a truck. The cut to fill guide explains when a block balances.
What Pushes the Count Up
- Topsoil strip. Stripping 100 mm of topsoil off a 400 m² lot is 40 m³ in the ground, which is six or seven more loads before the cut itself starts.
- Overcut. The pad is cut wider than the slab so the formwork and edge beams have room. That extra width is extra volume.
- Rock. Basalt floaters come out in their own loads and often go somewhere different from the clay. See hit rock on your site cut.
- Wet clay. Sticky clay doesn't fill a tray cleanly, so loads get lighter and the count goes up even though the volume didn't.
- Tight access. A smaller truck means more trips for the same soil. The estate truck access guide covers which truck fits.
The drawing gives you cubic metres. The tip gives you dockets. The swell factor is the difference.
Four Questions to Ask Before You Accept a Quote
- Is the price built on bank (in-situ) or loose volume?
- How many loads does that equal, and at what load size?
- What's the rate for each load over that number?
- Where does the spoil go, and will I get the tip dockets?
Want to run your own numbers? Our site cut calculator does the same maths with your measurements. For what those loads cost, see site cut cost in Melbourne.
Frequently Asked Questions
How many truckloads is a typical house site cut in Melton?
A flat estate lot with a detailed cut is often around 10 to 15 loads. A deeper cut, a bigger footprint or a sloping block can be 20 to 30 or more. The cut sheet decides.
How much soil does a tipper truck carry?
On clay we plan around 8 cubic metres of loose spoil per load. Lighter fill can sit closer to 10 cubic metres. Tight access trucks carry less.
Why is my load count higher than the volume on the drawing?
The drawing shows in-situ volume. Western Melbourne clay swells by roughly 30 per cent once it's dug, and trucks carry the loose volume.