If the concrete is structurally sound but worn or stained, resurfacing is the cheaper, faster fix; if the slab is badly cracked, sunken or failing at the base, replacement is the better long-term choice. The deciding factor is almost never how the surface looks — it's the condition of the slab and the ground underneath it.
Below we explain what each option actually involves, the clear signs that point one way or the other, a side-by-side comparison, and how a contractor works out which one you really need.
What does concrete resurfacing involve?
Resurfacing keeps your existing slab in place and applies a new layer over the top. The old surface is cleaned and prepared, any minor damage is repaired, and a thin overlay or resurfacing product is bonded over the concrete to restore the look and finish. You can often add colour, texture or a decorative pattern at the same time. Because there's no breaking out, excavation or new pour, concrete resurfacing is quicker, less disruptive and much cheaper than starting again — but it only works when the slab beneath is still strong.
What does concrete replacement involve?
Replacement means removing the old slab entirely and laying a new one. The existing concrete is broken out and carted away, the base is re-excavated and re-compacted, drainage and falls are corrected, new reinforcement is set, and fresh concrete is poured and finished. It's a bigger job that costs more and takes longer, but it resets the clock — you get a brand-new slab with a full lifespan and any underlying base or drainage problems fixed properly rather than covered up.
When should you resurface?
Resurfacing is the right call when the problem is on the surface, not in the structure. Consider it when you have:
- Surface wear: scaling, spalling, a rough or flaking top layer, or general age-related tiredness.
- A dated or plain look: you want to modernise with colour, texture or a decorative finish without a full rebuild.
- Minor damage: fine, stable hairline cracks, small chips or stains that can be repaired before the overlay goes on.
- A sound base: the slab sits level, doesn't rock or sound hollow, and there's no sign of sinking or base failure.
If that describes your driveway or patio, driveway resurfacing can give you a like-new surface for a fraction of the cost of replacement.
When should you replace?
Replacement is the smarter long-term choice when the slab or its base has failed. The signs to watch for are:
- Deep or structural cracks: wide, deep or actively moving cracks that run through the full thickness of the slab.
- Sinking or heaving: sections that have dropped, lifted or become uneven, which point to movement below the surface.
- Drainage or base failure: water pooling from lost falls, washed-out or soft ground, or a base that no longer supports the slab.
- Extensive damage: problems spread across most of the slab, exposed reinforcing, or concrete that crumbles or rocks underfoot.
Laying a new surface over any of these just hides the problem for a season or two before it returns. In these cases replacement is the honest, more economical answer over time.
Resurfacing vs replacement: side-by-side comparison
Here's how the two options compare across the factors that matter most:
| Factor | Resurfacing | Replacement |
|---|---|---|
| Cost | Lower — a fraction of a full rebuild | Higher — includes removal, base and new pour |
| Disruption | Minimal — often done in a day or two | Greater — several days, with break-out and curing |
| Lifespan | Typically 8–15+ years on a sound slab | A full new slab lifespan (20–30+ years) |
| Suitable when | Slab is sound; surface is worn, stained or dated | Slab is cracked, sunken or failing at the base |
How does a contractor decide which you need?
A good contractor won't guess from a photo — they'll assess the slab in person. That means checking the width, depth and movement of any cracks, looking for sinking or uneven sections, tapping the surface to listen for hollow or drummy areas that signal the base has separated, and reviewing drainage and falls. If the base is solid and the issues are cosmetic, they'll recommend resurfacing or targeted concrete repair. If the structure has failed, they'll be upfront that replacement is the better investment — because resurfacing a failing slab only wastes your money.
Still not sure which one you need?
The safest way to decide is to have someone look at the slab and the ground beneath it. We'll assess the cracks, base and drainage, tell you honestly whether resurfacing will hold or replacement makes more sense, and give you a clear, itemised quote either way. Contact us or call 09 886 7171 to book a free on-site assessment.