Why concreters charge a minimum for small jobs in Perth

Someone wants a 6 m2 pad for the bins, gets a number back that starts with a 2, and reasonably asks how a slab the size of a dining table can cost nearly what a 15 m2 side path costs. Fair question. On a small pour, the concrete is the cheap part. Almost everything else costs the same whether the slab is 6 m2 or 15 m2.

What actually costs money on a small pour

At our standard 100mm thickness, a 6 m2 bin pad takes 0.6 of a cubic metre of concrete and a 15 m2 path takes 1.5. Both are a splash in the bottom of an agitator truck, and both need that truck to leave the plant and come back mostly empty. Suppliers charge a part load fee for exactly that reason.

Now look at the rest of the job.

What the job needs	6 m2 bin pad	15 m2 path	Scales with size?
Site visit and written quote	1 visit	1 visit	No
Crew and vehicles on site	Full crew, one day	Full crew, one day	No
Set out, formwork, sub-base prep	Same setup	Same setup	Barely
SL72 mesh and concrete	0.6 m3	1.5 m3	Yes
Delivery and part load fee	1 truck	1 truck	No
Return visit to cut control joints	1 visit	1 visit	No

Four of those six lines don't move at all. Same crew, same set out, same pour and cure process, same return visit to cut the joints. Only the concrete and the mesh really scale, and they're the smallest cost on the sheet.

That's the whole reason a minimum exists. It isn't a penalty. It's the floor under a day of work.

The bin pad and the path, side by side

In plain concrete, both jobs land on the same number: $2,500 including GST, the small job minimum. That's about $417 per m2 on the bin pad and about $167 per m2 on the path. It's the same day's work landing on less slab, and the flip side is useful: the path is more than twice the area for the same money.

The finish barely matters this far down the scale. A 12 m2 liquid limestone courtyard and an 8 m2 honed concrete landing both come out at $2,500 too, because the mobilisation is doing the talking, not the material.

The sliding scale, in real numbers

We publish a size factor that multiplies the per square metre rate. The bigger the pour, the further the fixed costs spread, and the cheaper each metre gets. All the figures below include GST.

Job size	Size factor	Worked example in plain concrete	Effective rate
Under 20 m2	x1.25	15 m2 hits the $2,500 minimum	about $167 per m2
20 to 29 m2	x1.15	25 m2 = $2,150 to $3,200	$86 to $128 per m2
30 to 79 m2	x1.00	50 m2 = $3,750 to $5,500	$75 to $110 per m2
80 to 149 m2	x0.95	100 m2 = $7,100 to $10,450	$71 to $105 per m2
150 m2 plus	x0.90	200 m2 = $13,500 to $19,800	$68 to $99 per m2

Same crew, same mesh, same finish. The metre gets cheaper because the fixed costs stop dominating.

Where the minimum stops applying

The $2,500 minimum applies under 20 m2. At 20 m2 it drops away entirely, and that makes a line worth knowing about.

• 18 m2 of plain concrete: $2,500, the minimum
• 19 m2 of plain concrete: $2,500 to $2,650
• 20 m2 of plain concrete: $1,700 to $2,550

If your job sits at 17 or 18 m2, another couple of metres of slab costs you next to nothing. At 20 m2 the top of the range is $50 over the minimum and the bottom is $800 under it. Widen the path. Square off the corner. You're already paying for the day. Slide the area up and down in the instant estimator and you'll see the step yourself.

Three ways to get better value out of a small pour

Bundle every small pour into one visit. This is the big one. A 6 m2 bin pad, a 9 m2 side path and a 12 m2 shed slab priced separately are each under 20 m2, so each hits the minimum: three visits, $7,500. Poured together as 27 m2 on one day, plain concrete comes out at $2,300 to $3,450. Same slabs, same finish, four to five grand less. It only works if they all go down on the same day and the truck or pump can reach the lot, which is what the site visit is for.

Go in with a neighbour. If the place next door is getting a path or a driveway around the same time, say so when you ask for a quote. One crew and one truck on one street beats two separate mobilisations, and we'd rather price it that way than turn up twice.

Time it alongside a bigger job. If the exposed aggregate driveway is happening anyway, that's the moment to add the bin pad, the aircon slab and the strip down the side. The crew is there, the truck is coming. Adding small areas onto a bigger pour is about the cheapest concrete you'll ever buy.

Be careful with the cheap quote on a tiny job

If someone quotes $900 for a 6 m2 bin pad, the money has to come from somewhere. Usually they're squeezing it in between two real jobs, so your pour happens when it suits them. Or they're taking it out of the slab: thinner than 100mm, light mesh or none, no control joints cut, prep skipped. You won't see that on the day. You'll see it in two summers, when the slab cracks straight across the middle. Or the money comes back later as variations.

A concreter who tells you a small job has a floor under it is telling you what the day really costs.

Get your own number first

Put your area and finish into the estimator before you ring anybody. Real range, about 30 seconds, no email gate, off the same rates published on this page. When you want a written fixed quote, get in touch and we'll come and look at the site. Free site visits right across metro Perth.