How Thick Should a Shed Slab Be?
Shed slab thickness in Bendigo depends on what the shed will be used for and what loads it needs to carry:
- Garden and light storage sheds: 100mm is the standard minimum for a stable, durable base
- Workshops and garages: 125mm is recommended where vehicles or regular foot traffic are involved
- Machinery, hoists, and heavy equipment: 150mm or greater, with additional reinforcement specified for the load
- Edge thickening: A thickened perimeter beam — typically 200–300mm deep — is standard on quality shed slabs to anchor the wall frame and resist edge movement
- Sub-base: Every slab sits on 75–100mm of compacted road base or crushed rock — in Bendigo’s clay soils this step is non-negotiable for long-term stability
Thickness alone doesn’t decide how well a slab performs. Sub-base compaction, mesh placement, and a correct drainage fall all play an equal part — especially here in central Victoria where reactive soils and temperature swings put concrete under real, sustained pressure.
Why the Slab Is the Most Important Part of Any Shed Project
Most people spend a lot of time picking the right shed kit and not nearly enough time thinking about what goes underneath it. But the slab is the decision that affects everything else.
A poor base doesn’t just look bad — it causes real structural problems above ground. Doors bind because the frame has shifted. Walls rack because there’s nothing solid holding them true. Water gets in because the fall wasn’t right or the edges weren’t sealed properly.
Every other part of your shed sits on top of what we pour. That’s why we treat the slab as the most important part of the whole project — not an afterthought, not the cheap bit at the start. Getting it right means the shed above it does its job for years without giving you grief.
Getting the Size and Thickness Right for Your Shed
Getting the dimensions and thickness wrong from the start creates problems that can’t be fixed without pulling the slab up and starting again. We get this right before a drop of concrete is poured.
Slab Dimensions and Overhang Allowance
The slab footprint needs to match the shed’s base dimensions plus a standard perimeter overhang — typically 50–100mm on each side. That overhang gives the wall frame a solid surface to sit and fix to, and stops the slab edge from sitting flush with the shed wall where moisture and edge damage become a problem.
Thickness by Shed Type
The right thickness comes down to what the shed will actually be used for:
- Garden and light storage sheds: 100mm is our standard minimum
- Garages and workshops: 125mm where vehicles or heavy foot traffic are involved
- Machinery, hoists, and heavy equipment: 150mm or more, with reinforcement to match the load
Sub-Base Preparation in Bendigo's Clay Soils
The concrete is what you see, but what’s underneath it is what makes it last.
Bendigo’s clay soils move — they expand when wet and shrink when dry. That cycle puts pressure on anything sitting on top of them, and a slab poured straight onto unprepared ground won’t hold up for long. That’s why sub-base preparation is something we take seriously on every job we do here, regardless of shed size.
We start by excavating and removing the topsoil layer, which is too soft and organic to build on. From there we lay and compact 75–100mm of road base or crushed rock to create a firm, stable platform that doesn’t shift with the seasons. That compaction step is what separates a slab that stays flat from one that cracks and settles unevenly over time.
In other parts of Victoria the soil is more forgiving. In Bendigo, skipping or rushing this step is where most slab problems start. We don’t cut corners on it.
Reinforcement, Edge Beams, and Structural Details
The concrete gives the slab its mass. The reinforcement is what holds it together when the ground moves underneath it.
Steel Mesh Reinforcement: We lay steel mesh through every shed slab we pour. Its job is two-fold — it controls cracking if the slab flexes under load, and it distributes weight evenly across the full surface rather than concentrating stress in one spot. Mesh placement within the slab depth matters just as much as using it in the first place. Too low and it does nothing. We position it correctly every time so it’s actually doing the job it’s there to do.
Thickened Edge Beams: The perimeter edge beam is where the shed wall frame anchors to the slab. We pour this section deeper — typically 200–300mm — so there’s enough concrete mass to hold the fixing points firmly and resist any movement at the edges where the slab is most exposed. Without a properly thickened edge beam, the wall frame has nothing solid to grip, and that’s where racking and shifting starts.
If you’re ready to get your shed slab quoted, give us a call and we’ll come out and assess the site.
Drainage and Surface Falls — Keeping Water Out
A flat slab sounds right but it’s actually wrong. Every shed slab we pour has a deliberate fall built into the surface — typically away from the shed opening — so water drains out rather than sitting on the floor or tracking under the walls.
Get the fall wrong and water pools inside the shed after rain. It sits against the base of the wall frames, works its way under stored equipment, and over time causes rust, rot, and damp that’s hard to fix. In Bendigo where summer storms can drop a lot of rain quickly, a slab without a proper fall causes real headaches.
We factor drainage direction into every job before we set the formwork. It’s not something that gets sorted at the end — it has to be planned from the start and built into the pour. Every shed slab we do leaves site with water going exactly where it should.
Large Workshop and Commercial Shed Slabs
Bigger sheds and commercial applications need more than a standard residential pour. The loads are heavier, the consequences of getting it wrong are greater, and the specification has to reflect that from the start.
Shed Slabs Across Bendigo and Surrounding Rural Properties
A big part of what we do is out on rural properties — farm sheds, machinery sheds, and hay sheds across Marong, Axedale, Elmore, and Heathcote. These jobs come with their own set of challenges that suburban work doesn’t.
Site access is often the first thing to sort out. Getting concrete and equipment to a rural property takes planning, and we’ve done enough of these jobs to know how to get it right without delays. The volumes are larger, the loads are heavier, and agricultural equipment puts real demands on a slab that a garden shed never would.
We treat rural jobs with the same preparation and specification discipline as any suburban Bendigo pour. The sub-base still gets properly compacted. The thickness and reinforcement still get matched to the intended use. The drainage fall still gets built in from the start.
Whether the job is a backyard shed in Bendigo or a large machinery shed out past Heathcote, we bring the same standard to every slab we pour across the region.
Frequently Asked Questions
Most residential shed slabs take a day to pour. The prep work — excavation, compaction, and setting the formwork — usually happens the day before. We’ll give you a clear timeline when we quote the job.
We recommend waiting at least seven days before erecting the shed frame. The concrete reaches most of its working strength in that time. For heavier structures we may advise waiting longer — we’ll tell you at the time of the pour.
It depends on the size of the shed and your property. Smaller garden sheds often fall under exempt development, but larger structures typically need a permit. We recommend checking with the City of Greater Bendigo before the job starts. We can help point you in the right direction.
We handle that as part of the prep work. We excavate and grade the site before laying the road base, so by the time we pour, the surface is correctly set up regardless of what the ground looked like when we arrived.
Yes. Sloped blocks are something we deal with regularly around Bendigo and on rural properties. Depending on the degree of slope we may need to cut and fill or use stepped formwork. We assess this during the site visit and factor it into the quote.
The principles are similar but the specification differs. House slabs are engineered to AS2870 standards for reactive soils and carry more complex load requirements. Shed slabs are simpler, but they still need correct thickness, reinforcement, and sub-base preparation — especially in Bendigo’s clay soils.
We handle everything. We organise the concrete supply, the pour, and the finish. You don’t need to deal with a separate supplier — it’s all part of what we do.
Get a Free Quote for Your Shed Slab in Bendigo
Getting your shed slab right starts with a proper site assessment — not a guess over the phone. We come out, look at the ground conditions, talk through what the shed will be used for, and give you a straight quote on what the job actually involves.
No runaround, no vague estimates. Just honest advice and a clear scope from a local team that knows Bendigo’s soils and what it takes to pour a slab that lasts.
Call us today or request a quote online — we service Bendigo and the surrounding region, and free on-site quotes are available.
Concrete Bendigo Pro 📞 0344 204 792
Ready to get started? → Get in touch or request a quote online → We assess the site and advise on the right specification → Job is scoped, quoted, and scheduled.
