How Does a Concrete Pump Truck Work for a House Slab?
By PumpX Team ·
If you are building a house or a big slab and a builder has said "we'll need a pump", it helps to know what actually turns up on the day. A concrete pump truck is not complicated, but a little understanding makes it much easier to plan the pour and avoid surprises on the invoice.
What the pump truck actually does
Ready-mix trucks bring the concrete from the plant. The pump is a separate machine (or truck) that sits beside the mixer, takes the concrete from a hopper and pushes it under pressure through steel pipe and rubber hose to the spot where it is being placed. Instead of ten people with wheelbarrows, one operator controls the flow with a remote and the placing crew guides the hose end.
The mixer truck backs up to the pump's hopper and discharges into it. The pump keeps feeding concrete while the next truck waits its turn, so the pour runs as a steady stream rather than a series of stop-start deliveries.
Boom pump or line pump?
There are two main types you will hear about.
| Boom pump | Line pump | |
|---|---|---|
| What it is | Truck-mounted, folding mast with a pipe along it | Trailer or small truck with a hopper and long hoses |
| Best for | Slabs, footings and suspended floors where the truck can park nearby | Backyards, narrow sites, driveways, hard-to-reach spots |
| Reach | Often 20 to 60 metres or more, depending on the machine | Hose runs of many metres, laid along the ground |
| Set-up | Needs space for outriggers and overhead clearance | Quicker in tight spaces, but more hose to lay and clean |
| Typical cost | Higher hourly rate | Usually lower, but you pay for hose length and set-up time |
For a normal house slab with the street out the front, a boom pump is common because it places concrete quickly and with less labour. If your block is steep, has a narrow side passage or the truck can not get close, a line pump makes more sense. You can compare typical machine sizes on our machine specs page.
How the day usually unfolds
- Arrival and set-up. The operator parks, levels the truck, extends the outriggers and checks for overhead power lines. This can take 20 to 40 minutes.
- Priming. The pipes are lubricated with a slurry of cement and water so the first loads do not block the line.
- Pumping. Concrete is placed, usually starting at the far end of the slab and working back. The crew screeds and levels as they go.
- Clean-out. The pump and hose must be washed out. You need a spot on site where the washout water and waste concrete can go, so ask the pumping company what they need.
Most pump hire is charged by time on site, with a minimum hire period, so a well-prepared site finishes sooner and costs less.
What you need to organise
- Access and parking. The pump truck is heavy and needs a firm, flat spot. Soft ground, steep verges and overhanging trees or wires all cause problems.
- Reinforcement and formwork finished and inspected before the trucks are booked. Late inspections are one of the most common reasons pours are delayed.
- Enough people. Pumping is fast. If you have too few people to place and finish, you are paying pump time while the concrete waits.
- A clear plan for the order of the pour, including where the first truck should start.
Do I really need one?
For a small slab where a mixer truck can reach with its chute, you might not. For larger slabs, anywhere the truck can not get close, or where speed matters (hot weather, long runs, big volumes), a pump often pays for itself in labour saved and a better finish. Our guide to pump vs chute vs barrow goes through the trade-offs in more detail.
Key takeaways
- A pump moves concrete from the mixer truck to the pour point through a boom or hose, with one operator running it.
- Boom pumps suit open access; line pumps suit tight or awkward sites.
- Charges are mostly time-based, so being ready when the pump arrives saves money.
- Have the formwork, steel and inspections signed off before you book trucks.
- Ask your builder or pumping company what reach and access they need before the day.
Need a local operator? Search the concrete pumping directory on PumpX and get quotes for your pour.
Original question on Reddit: r/Homebuilding: Concrete pump truck question