Service
Concrete Slabs for Homes, Garages, Sheds and Extensions
Everything built on a slab depends on it: the walls of an extension, the roller door of a garage, the frame of a garden shed. A slab poured out of level, on a poorly compacted base or without the right reinforcement causes problems for years. Rowville Concrete arranges shed slabs, garage floors, extension and house slabs, footings and backyard slabs across Rowville and surrounding suburbs. For structural work, it's prepared to the engineer's design for your site.
Slab services
Shed slabs
Garden sheds, workshops, garages-in-a-kit and machinery sheds all need a level, square slab of the right size, with any hold-down bolts or rebates set out to the shed manufacturer's plans. Get the slab dimensions and bolt positions to your concreter before the pour, not after.
Shed slabs →Garage floors and carports
New garage floors, infill slabs where an old floor has been removed, and carport slabs. A garage slab usually has to meet the driveway at a set level and fall toward the door, so the two are best planned together.
Garage slabs →Extension slabs and granny flats
Rear extensions, studios, home offices and secondary dwellings usually need a slab and footings designed by an engineer, based on the site classification. The concreter's job is to build exactly what the design specifies and to coordinate inspections with your builder or building surveyor.
Extension slabs →House slabs
Full house slabs for new homes and knock-down rebuilds, including waffle-pod and raft designs as engineered. House slabs are structural building work, so they're always poured to the engineering design and building permit, with inspections at the stages the building surveyor requires.
House slabs →Footings
Strip and pad footings for extensions, decks, pergolas, retaining walls and fences, plus pier holes and pier caps. Footing depth and size come from the design, not a guess.
Backyard slabs
Slabs for water tanks, bins, spas, trampolines, clotheslines, basketball areas and general hard-standing. Simple jobs, but they still need a proper base, level and fall.
Basements (enquiry)
Basement construction involves significant engineering, excavation and waterproofing. Basement enquiries are welcome, and we'll arrange the right specialist input for your project.
How slabs are prepared
- 01Plans and design first: for structural slabs, the engineer's drawings and site classification set the thickness, beams, reinforcement and any piers.
- 02Set-out: the slab outline is set out from the plans, and for sheds from the kit dimensions, then checked square.
- 03Excavation and levelling: topsoil and unsuitable material removed, cut and fill balanced, and fill compacted where it's used.
- 04Base and membrane: compacted crushed rock and, where specified, a vapour barrier or membrane.
- 05Formwork: edge forms set to level and height, braced so they don't move during the pour.
- 06Reinforcement: mesh and bar placed on chairs at the specified cover, lapped and tied correctly.
- 07Services and set-downs: plumbing, conduits, set-downs for showers or doors, and hold down bolts placed before the pour.
- 08Inspection: where a building permit applies, the pre-pour inspection is booked before any concrete arrives.
- 09Pour, finish and cure: placed, vibrated, screeded, finished to the required surface and cured.
Ground conditions and site classification
Structural slabs in Victoria are designed around the site classification under Australian Standard AS 2870, which considers how much the ground is likely to move as it wets and dries. Melbourne's soils vary a great deal. A 2016 study published in Australian Geomechanics tested soils from dozens of sites across 37 suburbs. It found large variation even within the same soil type, with the most highly reactive soils mainly in the western and northern suburbs. Two blocks in the same street can behave differently, which is why a site-specific soil report, not a suburb rule of thumb, sets the design.
For non-structural slabs such as sheds, paths and tank pads, a well-compacted base, suitable reinforcement and sensible joint spacing do most of the work. Your quote should say what's being allowed for.
Local considerations
Sloping blocks and cut-and-fill
On sloping sites, common in the Dandenong Ranges foothill suburbs of Ferntree Gully and Boronia and on hillier streets in Endeavour Hills and Lysterfield, a level slab means either cutting into the slope, building up with compacted fill, or both. Deep edges may need a retaining wall or thickened edge beam. These details are designed and quoted up front.
Retaining walls →Access for trucks and pumps
Many backyard slabs sit behind the house, with only a side path for access. A concrete pump can place concrete over the house or down a narrow side path, and pumping is often the difference between a clean pour and a long day of wheelbarrows.
Concrete pumping →Permits
Sheds, garages and extensions may need a building permit, depending on size and location. Your building surveyor or council can confirm. If a permit applies, the slab is poured to the approved plans, and inspections are booked at the required stages.
Slab surface finishes
- Steel trowel: smooth and dense, suited to garage floors, workshops and slabs that will be sealed, painted or epoxy-coated.
- Broom: textured for grip on outdoor slabs, tank pads and bin areas.
- Ground or polished: for slabs that will be the finished floor in a studio, extension or shed fit-out. Polished concrete →
What affects your slab quote
- Slab size, thickness and any edge beams or internal beams
- Engineering requirements (waffle pod, raft, piers)
- Excavation, cut-and-fill and removal of spoil
- Base, membrane and reinforcement specification
- Access for trucks, or the need for pumping
- Plumbing, conduit and set-down coordination
- Finish (steel trowel for garages and workshops, broom for outdoor slabs)
- Inspections and scheduling around your builder
Slab FAQs
It depends on what the shed will hold and on your ground. A garden shed for tools is a different job to a workshop with a car hoist or a machinery shed. Shed suppliers often specify slab requirements. Give those to your concreter so the quote matches.
The slab itself usually follows whatever permit the building on top needs. Sheds and garages over certain sizes, and all extensions and houses, may need a building permit. Your building surveyor or council can confirm what applies.
Your concreter and builder will advise based on the mix and weather. Concrete gains strength over weeks, and heavy loads should wait for the recommended curing time.
Yes. Provide the kit's slab plan with bolt positions and we'll set them out before the pour, or allow for drilled anchors afterwards if the manufacturer prefers.
Often, yes, and it helps get the levels between the two right. The garage floor needs a finish suited to indoor use, while the driveway usually has a textured outdoor finish.
Related slab services
Extension slabs → · Garage slabs → · House slabs → · Shed slabs →
Slabs by suburb
Shed and backyard slabs are common in Ferntree Gully, Lysterfield South, Narre Warren North and Scoresby. Extension and unit slabs are frequently requested in Glen Waverley, Wantirna South and Knoxfield.
Request a slab quote
Send the slab size, what it's for, any plans or shed kit drawings, and photos of the site and access. You'll get a written, itemised quote after a site look.