The deciding factor is whether the concrete underneath is still sound. When the slab is whole and the wear is only skin deep, a new surface can make the driveway look close to new at a far lower price. When the slab is shifting, or the ground beneath has given way, an overlay just pays to disguise a fault that will show again before long.
Below we explain how to read the signs, what each job involves and how local conditions change the picture: reactive clay in some suburbs, soft alluvial ground on the Barron delta, summer storms, hot sun and blocks where a truck can barely reach the back of the drive.
How a concrete overlay works
An overlay is a new layer bonded to the slab you already have. The existing concrete stays put and acts as the foundation for the new surface. Most of the effort goes into preparation: the old surface is ground back with diamond tooling so the topping can grip, and every crack is checked and treated. The topping is then laid, finished in whatever style you have chosen, whether plain, patterned, tinted or textured, and sealed. It needs careful curing like any fresh concrete, which locally means working outside the midday heat and keeping it covered if a downpour rolls in. Our concrete resurfacing page covers the finishes in more detail.
What a full rebuild involves
A rebuild starts with demolishing the slab, loading the rubble, trucking it off and covering disposal fees. The ground is then dug out, a new base of compacted crushed rock is laid and the driveway is poured again from the ground up. It is a far bigger job, and where the block falls away steeply or the drive squeezes between older homes, getting an excavator in and debris out adds real cost. The upside is that the underlying cause can finally be corrected, whether that was storm water pooling under the slab, too little crushed rock over reactive clay or reinforcement sitting too low. When the base has failed, correcting the root cause is the real value of starting again. See our concrete removal service for how the break-out stage is handled.
Signs an overlay will do the job
An overlay makes sense when the slab is solid and the problem is about looks.
- A rough, faded or patchy finish over concrete that is otherwise whole.
- Marks and discolouration left by oil, fallen leaves, mould or years of sun.
- Light crazing, the fine web of shallow surface cracks that is not getting worse.
- An old-fashioned look that no longer matches the house.
Here the slab is still carrying its load and only the top has worn. A new surface fixes precisely that, and you hold on to the existing base, steel and levels.
Signs the slab has to come out
A rebuild is the honest answer once the slab no longer moves as a whole.
- Cracks that keep opening instead of staying put, typically where clay soil expands in the wet and contracts again in the dry.
- Panels that sit higher or lower than their neighbours, a sign the slab has split into separate pieces.
- Flaking with rust marks, which tells you the steel inside is corroding and swelling.
- Broad areas of scaling where a surface that cured badly, often because it dried out too quickly in the heat, has broken up.
Each of these points to trouble in the base, the steel or both. A fresh surface over a failing slab might hold for a few months until the old cracks push through again, and then you have paid for an overlay and still face the rebuild.
Overlay versus rebuild at a glance
This table sets out the main trade-offs.
| Resurfacing | Replacement | |
|---|---|---|
| Cost | Well below a full rebuild | Covers demolition, rubble removal, disposal, new base and fresh pour |
| Disruption | Usually a few days, nothing demolished | A longer job with machines on site and debris trucked out |
| Lifespan | Many years, limited by the concrete underneath | The full life of new concrete, typically 30 to 40 years |
| Best suited to | Solid slab with a tired or dated surface | Slab cracked right through, sinking, or sitting on a failed base |
How we assess your driveway
We look past the surface to what is causing it. That means checking which cracks are still moving, whether panels have shifted against each other, where storm water goes, particularly if runoff cuts across the drive or pools along an edge, and whether there is any rust bleeding from the steel. Only after that can we tell you which option your concrete genuinely needs.
Still unsure? Send through some photos
A wide shot of the driveway, a handful of detail photos of the cracks that worry you most and any spots where the levels change, are normally enough for an initial view. If it looks suited to an overlay, we will visit, check it in person and put a price in writing. Should it need rebuilding instead, you will hear that from us plainly.