Nupave recommended external concrete specification — Carrum
Group 1 — Bayside / Sand Belt — Brighton Group Sands
Concrete: N25 or N32 (depending on application)
Indicative regional ground conditions
Carrum sits on the Bayside / Sand Belt, where the natural profile is dominated by free-draining Brighton Group sands. Regional ground conditions are generally stable and low-reactivity, though loose sand pockets can require additional compaction. The actual AS 2870 site classification for any individual property can only be established through a site-specific geotechnical investigation, taking into account soil profile, fill, moisture conditions and vegetation.
Regional ground movement (indicative, AS 2870)
Ground of this type may exhibit generally low seasonal surface movement (indicatively under 20 mm). This is a regional indicator only — actual movement at a given address depends on soil profile, moisture history and tree influence.
| Application | Slab thickness | Sub-base | Reinforcement |
|---|---|---|---|
| Path / foot traffic | 75–100 mm | 50–75 mm compacted crushed rock | SL72 |
| Driveway (cars up to 3 t) | 100 mm | 75–100 mm compacted crushed rock | SL72–SL82 |
| Occasional truck (3–10 t) | 125–150 mm | 100 mm compacted crushed rock | SL82 or rebar |
Nupave standard specification for typical conditions of this soil group — subject to site-specific assessment. Not a design substitute for a project engineer’s report where one is required.
| Saw-cut / control joint spacing (100 mm slab) | |
|---|---|
| Spacing between cuts | 2.7 m – 3.0 m (standard spacing) |
| Cut depth & timing | At least 25 mm on a 100 mm slab (¼ slab thickness). Saw-cut as soon as the concrete can be cut without excessive ravelling — timing will vary with the mix, weather and saw type. A quick trial cut on a low-visibility edge or offcut is best practice before committing to the full grid. |
| What joints do | Closer joint spacing and properly proportioned panels encourage drying-shrinkage and thermal movement to occur at planned locations. Control joints reduce the risk of random cracking; they do not prevent cracking caused by inadequate support or differential ground movement. |
| Panel shape | Keep panels close to square (length ≤ 1.5× width). Long, narrow panels are more prone to random cracking regardless of joint spacing. |
Concrete grade
Nupave specifies N25 or N32 concrete depending on the intended application, anticipated loading, exposure conditions, selected finish and any site-specific engineering requirements. N32 may be specified where increased compressive strength, abrasion resistance or durability is required. Concrete strength alone does not compensate for inadequate subgrade preparation, drainage or ground movement — it is one element within a properly detailed slab system.
Slip layer (poly membrane)
A polyethylene separation or slip membrane may be considered where required by the slab design or site conditions. It can reduce friction between the slab and compacted base during concrete shrinkage, but does not prevent settlement, heave or other vertical ground movement. Where a project engineer or geotechnical report specifies membrane use, that specification takes precedence.
Sub-base — why it’s a key part of the quote
Correct excavation, drainage, and a uniformly compacted crushed-rock base significantly reduce settlement and provide consistent support under the slab. It adds cost — both in laying and compacting the base, and in the extra excavation and spoil-removal that comes with the deeper dig — but that preparation is what a slab needs to perform over the long term. The preparation actually required may vary where uncontrolled fill, soft areas or unsuitable material are encountered on the specific site.
Curing coat
Concrete requires curing to develop its full design strength and durability. A liquid curing coat is applied after finishing, once bleed water has disappeared and in accordance with the manufacturer's requirements. It seals moisture into the concrete so hydration continues over the first 7 days — when the concrete's real strength develops. In summer, hot dry weather removes surface moisture quickly, so curing coat is essential to prevent surface crazing and reduced final strength. In winter, lower temperatures slow hydration, so curing is still required to reach design strength — the curing coat is still applied, and duration may need to be extended. Nupave applies curing coat as standard on all pours year-round.
Microfibres in concrete mix Optional add-on
What fibres actually do. Microfibres (polypropylene) get mixed through the whole pour and mainly control plastic shrinkage cracking in the first 24 hours, plus improve abrasion / impact resistance — they don’t add real structural tensile capacity. Macrofibres (heavier synthetic or steel) go further, adding post-crack toughness and some flexural strength.
Genuine benefit as an add-on: reduces fine / hairline shrinkage cracking and improves durability on any slab, sand or clay.
Should NOT replace mesh on soft or highly plastic clay soils: fibres provide no real resistance to the larger, ground-movement-driven cracks that mesh or rebar controls.
Salt / coastal exposure
Suburbs within roughly 1 km of Port Phillip Bay are subject to salt spray. Nupave uses B1 exposure classification (N32 minimum) and increases concrete cover to reinforcement on foreshore-proximate work to protect against saline-induced corrosion.
Important: This is Nupave’s enhanced standard specification for typical conditions in this suburb group, and is presented as a general reference. It is not a site-specific engineering design. Actual specifications for any individual property may vary based on site conditions, uncontrolled fill, tree influence, drainage, or requirements identified in a site-specific geotechnical or engineer’s report. Where an engineered design has been prepared for the site, that design takes precedence.
If your Carrum concrete is past resurfacing or there’s nothing there yet, new concrete is the answer. We organise the pour through our trusted contractor network and handle the finish in-house — plain grey, coloured, or exposed aggregate.
New concrete vs resurfacing — the practical difference
Resurfacing keeps your existing slab and refreshes the look. New concrete replaces the slab entirely. The cost difference is significant — resurfacing typically 40–60% less.
When new beats resurfacing
Sometimes the existing slab is just too far gone for a coating system to hold. If the underlying movement, cracking or drainage problems aren’t addressed, no resurfacing finish will last. In those cases we recommend a new pour and walk you through what’s involved.
Resurfacing as the cheaper option
If the existing slab is structurally sound but visually tired, a resurface in spray-on, slate impression, stencil or Timbercrete is usually cheaper and faster than tearing out and pouring new.
Exposed aggregate as the decorative upgrade
If you’re already doing a new concrete pour, exposed aggregate is usually the decorative upgrade worth considering. The aggregate is mixed into the pour and exposed at the surface — giving you a textured, slip-resistant, hard-wearing finish.
Why Nupave
Nupave is family-owned and has been working in decorative concrete since 1993. We are not trying to sound bigger than we are — Shaun answers the phone, checks the work, and spends his days on the tools. No subcontractors, no pushy sales process, no deposit.
Other Concrete Services in Carrum
Frequently Asked Questions
Are there jobs Shaun will not take on?
Yes. I won’t coat concrete that is moving too badly, breaking up, full of moisture, badly contaminated, or clearly needs replacement instead of resurfacing. I would rather walk away than take your money for a job I know will not hold up.
Will the colour fade over time?
All outdoor coatings can change over time with sun, wear and cleaning. A proper sealer helps protect the colour, and resealing every 2–5 years keeps the surface looking better and helps stop it drying out or wearing unevenly.
Plain grey or coloured concrete?
Plain grey is the cheapest. Coloured concrete adds a moderate cost increment for a finish that doesn’t fade or wear off the surface.
How long does a new concrete pour take?
Most residential driveway jobs are 2–7 days on site. Light foot traffic typically possible 24–48 hours after the pour; vehicle traffic about a week.
Call 0418 741 188 or email enquiries@nupave.com.au for a free on-site assessment and a written quote within a few business days. No deposit required.