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Shed slab cost and thickness, by shed type
This is shed country, and every shed stands or sags on its slab. Here is what each type needs under it and what that costs on our published card.
The table to screenshot
Rates are our published $110 to $150 per square metre for shed and garage slabs, laid over a prepared base with mesh on chairs. Working rates until we measure the job; after that the written quote is the price, full stop.
| Shed type | Typical size | Build | Lands around |
|---|---|---|---|
| Garden shed | 3 x 3 m, 9 m² | 100mm, SL72 mesh | $1,000 to $1,400 |
| Single garage | 3.6 x 6 m, 22 m² | 125mm, SL82 mesh | $2,400 to $3,300 |
| Double garage | 6 x 6 m, 36 m² | 125mm, SL82, thickened edges | $4,000 to $5,400 |
| Workshop | 6 x 9 m, 54 m² | 125mm, SL82, thickened edges | $5,900 to $8,100 |
| Machinery shed | 9 x 12 m, 108 m² | 125mm, SL82, edges and rebates to drawings | $11,900 to $16,200 |
Shed on order? That is the week to book the measure.
What moves a shed slab inside its band
The ground first. On the clay through Pakenham and Officer the base is routine. On the old swamp country around Koo Wee Rup and Cardinia the excavation and rock can be most of the job, and pretending otherwise is how wavy shed floors happen. The drawings second. Thickened edges, rebates and hold-down details come off the shed manufacturer's documentation, and pricing them at the measure keeps them off the invoice as surprises. Access third. A slab the trucks can reach beats one that needs a pump, and on rural blocks a new crossover brings the shire permit and its lead time into the schedule.
Do not forget the apron
The strip in front of the roller door cops the turning wear of every entry and exit, and pouring it with the slab costs a fraction of coming back later. The same logic extends to the driveway run connecting shed to road: one planned sequence, one mobilisation, better rates on every square metre. The calculator brackets any combination in seconds, and the specification shows the build standard every figure buys.
Fair questions
Shed slab questions, answered
How thick does a shed slab need to be?
Garden sheds sit happily on 100mm with SL72 mesh. Anything housing vehicles or machinery, garages, workshops, farm sheds, steps up to 125mm with SL82, thickened edges where the frame loads the perimeter, and rebates where the manufacturer’s drawings call for them. What lives in the shed sets the spec, so tell us about the hoist or the header at the measure, not after.
Can I just tell you the shed size over the phone for a price?
You will get an honest bracket that way, and the calculator does the same job online. The written figure needs a measure because the two biggest cost variables are invisible from the road: what the ground needs excavated and built up, and what the manufacturer’s drawings ask of the edges. On the soft country towards Koo Wee Rup those two lines can matter more than the slab itself.
Does the shed slab need a permit?
The slab itself sits outside our council permit process, but the shed above it commonly needs a building permit, which runs between you, the shed supplier and a building surveyor. Where trucks need a new or upgraded crossover to reach the site, Cardinia Shire’s Works Within a Road Reserve permit applies with its 28 business day lead time, and we run that. Order the shed and start the permit in the same week.
When can the shed go up after the pour?
The erection crew wants concrete at strength before they load it, and the practical rhythm is to book the shed build for a few weeks after pour day, with 28 days the safe marker for full strength under heavy point loads. We put the timings for your slab in writing at handover so the shed company can schedule against them.
Next step
Get the slab quoted before the shed arrives
One measure sets the excavation, the edges and the timeline, and the written figure holds while you order steel.
Straight to a person on (03) 6155 0209, 7am to 5pm weekdays, 8am to 1pm Saturday.