Residential concreting specification

Standard

Work is carried out with reference to AS 3727.1, the Australian Standard for residential pavements, and at crossovers to the City of Boroondara's standard vehicle crossing drawings. Where a council drawing and this specification differ at the crossover, the council drawing governs.

Preparation and base

The existing surface is removed and the area prepared to suit the ground: soft spots and organic material taken out, and compacted base material brought in where the site needs it. Boroondara's clay swells and shrinks with the seasons, so the base and the drainage do more for the life of the slab than any amount of extra concrete.

Membrane and reinforcement

A membrane is laid where the site requires it, and every slab is reinforced with steel mesh placed on chairs so the steel sits within the slab and can do its job.

Driveways

Typically 25 MPa concrete at around 100mm for passenger vehicles. A thicker slab with heavier mesh is quoted where caravans, boats or light trucks will use the driveway, and on shared drives serving more than one home.

Shed and garage slabs

Garden sheds with normal use are poured at 100mm with SL72 mesh. Garages, studios and workshops where vehicles, racking or machinery will sit are poured at 125mm with SL82 mesh, with thickened edges where the manufacturer's drawings require them. Rebates and hold-down points are formed to the supplier's drawings. These slabs are for outbuildings; this site does not quote dwelling slabs.

Paths

Paths are poured at 75mm minimum, and at 100mm where vehicles cross them. Falls are set so water moves off the path and away from the building line, which matters most beside the timber and brick walls of period homes.

Joints

Control joints are cut to direct any movement to planned lines, with isolation joints against the garage slab, house footings and existing concrete where needed.

Drainage and fall

Every slab is set with a fall away from the dwelling. Where the block falls towards the garage or the house, a grated strip drain is formed in and connected to the stormwater system. The grade at a crossover is set so a standard passenger vehicle clears the change of level, which takes real design on Boroondara's sloping streets.

Crossovers

The section between the boundary and the road is built to the council's standard drawing. The City of Boroondara requires a vehicle crossing permit before a crossover is built, widened, moved or removed, inspects the formwork before the pour and the finished work after, and in a heritage overlay a planning permit can be required on top of the standard permit. Council permit fees are not part of the quoted price and are confirmed at the quote.

Heritage frontages

New concrete against an old house is detailed, not just poured. Edges against bluestone kerbs, pitchers and original path borders are formed to a clean, consistent joint so the new surface meets the old material squarely rather than lapping it. Where an original front path or verandah edge is staying, levels are matched and the joint line is placed where the eye expects a break. Around the mature trees that make these streets, the slab edge is kept clear of protected root zones, with the base build-up adjusted rather than the roots cut, and street trees are never touched without the council's approval.

Finish and cure

Broom, steel trowel, full depth oxide colour or exposed aggregate as quoted. As a guide: foot traffic after 24 hours, passenger vehicles after seven days, heavy vehicles after 28 days. Exposed aggregate is sealed after cure as agreed at quote.

What this means for a quote

If a competing quote is materially cheaper, the difference is usually in the preparation, the mesh, or the thickness, none of which are visible once the concrete is poured. Ask for those three items in writing and compare them against this page, the cost guide and the calculator.