How to Quote a Concrete Slab in Australia
A slab is never just the concrete — it's the dig, the base, the formwork, the steel and the finish. Here's how to quote a concrete slab so the site prep and ground conditions don't sink your margin.
The fastest way to lose money on a slab is to price the concrete and forget everything around it — the excavation, the base prep, the formwork, the reo and the finish. Every site is different, so a blanket rate per square metre misses the detail that actually costs. Here's how to quote a concrete slab so a shed pad and a house slab each get the number they deserve.
What a good slab quote covers
A slab quote is a stack of stages, not a single pour. Break it out before you price it:
- Site prep and excavation — clearing, cut and fill, and getting machinery and trucks in.
- Base and sub-base — compacted road base to the specified depth.
- Formwork — timber or steel to define the shape and level.
- Reinforcement — mesh or bar to the engineer's design, plus bar chairs.
- Concrete — the mix and strength the job calls for, ordered per cubic metre.
- Finish — broom, trowel, exposed aggregate or polished, each priced differently.
- Spoil removal and curing — carting the dig away and protecting the pour, both real costs.
For any house or structurally critical slab, quote from the engineer's design, not a rule of thumb. AS 2870 covers residential slabs and footings, and the drawings dictate strength, mesh and footing depth — get them before you price.
Concrete and material costs in 2026
Concrete prices move with demand, fuel and cement costs, so get a fresh quote from your plant for every job. As a starting point for the core materials:
| Material | Typical cost | Notes |
|---|---|---|
| Concrete (25MPa) | $200–$250/m³ | 20MPa for shed pads, 32MPa for some house slabs |
| Reinforcing mesh (SL82/SL92) | Priced per sheet | To the engineer's design |
| Formwork timber | Priced per lin m | Plus stakes, screws and release agent |
| Vapour barrier (200 micron) | Priced per m² | Under-slab plastic to stop moisture |
Concrete strength follows the job — around 20MPa for shed slabs and 25MPa or 32MPa for house slabs, per the engineer. Add a vapour barrier and expansion joints to every slab, and order 5–10% extra concrete so a short load doesn't hold up the pour.
Labour and equipment
Pouring is the quick part — it's the prep, the finish and the clean-up that eat the hours. Price the full sequence: excavation, base prep, setting out, formwork, tying reo, the pour, screeding, trowelling and curing.
- Skilled concreters charge around $80–$100/hour; labourers run $50–$65/hour.
- A typical 60m² house slab takes roughly 60–80 hours of labour, depending on finish and access.
- Price the plant too — excavators, skid steers, power floats, vibrators and laser levels all carry a cost.
- A site the truck can't reach needs a concrete pump — often $1,500+ — and difficult access can add 15–25% to labour on its own.
Ground conditions, slab types and standards
Ground conditions decide the slab, and the slab decides the price. Check the soil before you commit to a design or a number.
- Reactive clay soils, common across Australia, often need a waffle pod slab or bored piers — more material and more labour.
- Conventional reinforced slabs suit stable ground; suspended slabs are for upper levels.
- Get a soil report (geotechnical investigation) rather than guessing the foundation.
- House and structural slabs need an engineer's design to AS 3600 and AS 2870; don't pour without it.
Common mistakes that eat your margin
- Guessing the ground. Reactive soil or rock changes the whole slab. Get a soil report or a proper inspection before you quote, not after you dig.
- Quoting off old prices. Concrete and steel move constantly. Confirm current rates with your plant (Boral, Hanson) the day you quote.
- Vague scope. Spell out who clears the site, removes the spoil and backfills. Leave it unsaid and it becomes your job for free.
- Forgetting difficult access. No truck access means a pump and slower labour. Confirm access and price the pump before you commit to a rate.
- No contingency. Build in at least 10% for rock, weather and the unexpected. Quote tight and the first bad day wipes your margin — aim for a 20–25% gross margin, not break-even.
Pro tips for a slab quote that holds
- Order 5–10% extra concrete so a short load never stalls the pour.
- Carry a minimum 10% contingency for ground and weather surprises.
- Confirm current concrete and steel prices with your supplier for every quote.
- Charge properly for difficult access — it drives both labour and equipment cost.
- Read the soil report so you don't under-spec the foundation.
- Itemise finishes and extras — exposed aggregate adds $30–$60/m² over a standard finish — so the customer sees the choice.
ServiceYak keeps your concrete, reo, formwork and finish rates in a reusable kit, so you can itemise a slab quote on site — mix, mesh and finish — and send a clean PDF the same day you inspect.
Frequently asked questions
How much does a concrete slab cost in Australia?
It depends on size, access and ground, but 25MPa concrete alone sits around $200–$250/m³, and a house slab carries far more in prep, steel and labour than the mix. A 60m² slab typically runs 60–80 hours of labour on top of materials.
How do I work out how much concrete a slab needs?
Multiply length × width × depth for the volume in cubic metres, breaking complex shapes into rectangles. Then add 5–10% for uneven subgrade and spillage — it's cheaper to have a little extra than to wait on a short load.
Do I need an engineer for a concrete slab?
For any house or structural slab, yes — the design must meet AS 3600 and AS 2870, and the drawings set the strength, mesh and footing depth. Quote from the engineer's plans, not a rule of thumb.