Costs and decisions
Resurfacing vs replacement
The surface looks finished but you do not know whether the slab underneath is.
Resurfacing is a fraction of the cost of replacement and can make an area look new. That makes it attractive, and it makes it easy to apply in situations where it does not belong.
The whole decision rests on the condition of the slab underneath, which is not something you can judge from how the surface looks.
What resurfacing needs to be true
The slab has to be structurally sound, sitting where it should, and not moving. Cracking has to be limited and stable. The concrete has to be capable of taking a bond after preparation.
Where all of that holds, resurfacing does something genuinely useful for a modest price, and it can last a long time.
What rules it out
Any settlement. An overlay follows the shape underneath; a settled slab resurfaced is a settled slab with a new top, and the water still pools in the same place.
Moving cracks. They transmit through, usually along the same line, often within a year.
Soft, crumbling or delaminating concrete. There is nothing sound to bond to.
Exposed, corroding reinforcement. That is a deeper problem than a surface treatment addresses.
How to judge the slab
Ask the contractor how they assessed it. Sounding it for delamination, probing the surface for softness, checking for movement across cracks, and — for coatings — testing for moisture are all real assessment steps. "It'll be fine" is not one.
A contractor who tells you a slab is not a resurfacing candidate is giving you the more valuable answer, because they are turning down work.
Resurfacing as a deliberate holding position
There is a legitimate version of resurfacing a slab that will eventually need replacing: you know it is coming, it is not this year, and you want the area usable and presentable in the meantime.
That is a reasonable decision when everyone is honest about what it is. It stops being reasonable when it is sold as a permanent fix.
What resurfacing does to a later replacement
This rarely comes up at the estimate and is worth asking about. An overlay adds material bonded to the slab, and when the slab is eventually removed that material comes out with it. In most cases that changes very little — it is a slightly thicker thing to break out.
Where it matters is height. An overlay raises the finished surface, and if that surface already sits close to a threshold, a door, a step or an adjoining path, the extra thickness can push it somewhere awkward. Ask what the finished height will be relative to whatever it meets, particularly at doorways.
It also matters if the overlay is thick or if a previous one is already present. Layering surface treatments over each other compounds the height problem and gives the newest layer a progressively less reliable thing to bond to.
What to ask a contractor
- How did you assess whether this slab can take an overlay?
- What happens at each existing crack?
- What is the realistic life of this system on this slab, in this climate?
- Does the warranty exclude cracking that reflects through from below?
- If I resurface now, does that complicate replacing it later?
Common questions
Can I resurface over a slab that has settled slightly?
An overlay does not correct elevation, so the settlement remains — and where the settlement is ongoing, the overlay cracks. If the slab is sound and the settlement is the only issue, lifting first and resurfacing afterwards is the order that works.
How long does a resurfacing last?
The range is very wide and is driven mostly by preparation and by whether the slab was a suitable candidate, not by the product. On a well-prepared sound slab it can last many years; on a poor candidate it can fail in a season.
Work it out, or judge the quote
Related guides
Resurfacing and overlays
A new wearing surface over sound concrete — and the movement problems it cannot fix.
Read more →Replacement and new flatwork
Removing failed concrete and pouring new — plus what separates a good pour from one that fails early.
Read more →Repair or replace?
The central question: when repair holds, when it is money spent twice, and how to tell.
Read more →Spalling concrete
Surface breaking away in chunks, often with aggregate showing — usually water, freezing and salt.
Read more →Patio cost factors
Where access, finish and the resurface-or-replace choice move a patio price most.
Read more →