Driveway Concrete Calculator AustraliaAS 3600
Driveway dimensions
Standard single driveway: 2.5–3 m wide. Standard double: 5–6 m wide.
100 mm is the minimum recommended by most Australian engineers for residential car driveways. AS 2870 and NCC Volume 2 require soil classification to determine slab thickness for reactive soils.
Concrete estimate
Volume
Bagged premix
Concrete volume = length × width × thickness. A 10% waste allowance is added to account for over-excavation, formwork variation, and spillage — consistent with standard Australian concreting practice. Premix bag yields: 20 kg bag = 0.010 m³, 25 kg bag = 0.0125 m³. For driveways over approximately 1 m³, ordering ready-mix concrete from a batch plant (Boral, Holcim, Hanson) is usually more economical and produces a more consistent N20 or N25 mix as specified under AS 3600 and AS 2870.
Frequently Asked Questions
How thick should a concrete driveway be in Australia?
The minimum recommended thickness for a residential car driveway in Australia is 100 mm. For driveways that will carry light trucks, trailers, or heavy SUVs regularly, 125 mm is recommended. On reactive soils (Class M, H1, H2 or E under AS 2870), a geotechnical engineer or certifier may specify thicker slabs or edge beams. 75 mm is insufficient for vehicle loads and should only be used for pedestrian paths.
What concrete strength (MPa) should I use for a driveway?
N20 (20 MPa) is the minimum recommended strength for a residential driveway in Australia, as referenced in AS 2870 for Class A and S soil conditions. N25 is commonly specified for more reactive soils, driveways in coastal areas (salt exposure), or where de-icing agents may be used (uncommon in most of Australia). Always follow your engineer's specification — ordering N25 over N20 adds only a small cost to a ready-mix order and provides significantly better durability.
Do I need steel mesh reinforcement in a driveway slab?
Steel reinforcement is strongly recommended for residential driveways. The standard practice is SL62 or SL72 mesh (square wire mesh) placed at mid-depth in the slab, on bar chairs. Mesh controls cracking from thermal movement, prevents cracks from widening, and extends the life of the slab. Rebar (N12 or N16) is used for more heavily loaded driveways. Note that reinforcement does not add structural strength to an unreinforced slab — it controls crack widths. Always place mesh at mid-depth, not on the ground.
Do I need a building permit for a concrete driveway in Australia?
In most Australian states, a residential driveway is exempt from requiring a building permit unless it involves a new vehicle crossing (the section from the road to the property boundary), which typically requires a separate crossing permit from the local council. The driveway on private property usually does not require a building permit, but always confirm with your local council. In some states, a driveway with a kerb crossing requires a public works permit.
How long does a concrete driveway take to cure?
Concrete reaches approximately 70% of its design strength after 7 days and full design strength (100%) at 28 days. For residential driveways: you can walk on it after 24–48 hours, and light passenger vehicles can drive on it after 7 days. Avoid heavy loads (trucks, loaded trailers) until 28 days. During curing, keep the slab moist — either with wet hessian, plastic sheeting, or a curing compound — especially in hot, windy, or low-humidity conditions typical of many Australian regions.