Resurface or Replace an Old Concrete Patio?
Updated October 2026
An old concrete patio can be resurfaced when the slab underneath is sound and the damage is only on top: pitting, scaling, a worn finish. Replacement wins when the slab has cracked into a road map, the base has failed, or the surface is too far gone to bond to. A slab that has settled or has growing cracks needs a look at what is moving first, because an overlay only bonds to a stable slab. A free site visit tells you which side of the line your patio is on.
Your patio is ten, fifteen or twenty years old. The surface is rough, pitted or stained, maybe flaking in patches. The question is whether it needs a new surface or a whole new slab. The answer depends on what is wrong underneath, not on how bad the top looks. Here is how to tell.
What resurfacing can and can’t do
Resurfacing is a surface fix. We grind off the weak layer, then bond a polymer-modified topping to the sound concrete below. The topping is thin, about 1/8 to 1/2 inch. That is why it works on a stable slab and fails on a moving one. A thin layer cannot hold up a slab that is still settling.
An overlay put on a slab that keeps moving cracks along the same lines as the slab under it. So the real question is never “how bad does the top look?” It is “what is the slab under it doing?” Our concrete repair and resurfacing page covers the method and the specs.
Signs a patio is a resurfacing candidate
Resurfacing is a good bet when the damage stays on the surface:
- Pitting and scaling. The top skin is rough or flaking, but the slab is solid. Salt and freeze-thaw chew concrete from the top down, and flaking and spalling after winter is often only the top layer.
- A worn or stained finish. The surface looks tired but the slab is flat and tight.
- Stable cracks. Hairline cracks that stay put are normal concrete behaviour.
- Solid when tapped. A sound slab rings. It does not sound hollow.
When the slab is sound, resurfacing gives you back a clean, even surface without the cost and mess of a tear-out and re-pour.
Signs a patio needs replacing
Replacement wins when the problem is below the surface or there is nothing sound left to bond to. Some of these signs call for a site visit to find the cause before anyone decides:
- Cracked into a road map. Cracking everywhere is one of the conditions where replacement wins.
- The base has failed across the whole area. The slab has lost what held it up, so resurfacing it will not last.
- Deep scaling or hollow sections. If there is nothing sound left to bond to, an overlay has nothing to hold on to.
- A slab that has settled or heaved (needs a look first). A slab that sinks has lost its base: washouts, poor compaction and Ontario clay working through freeze-thaw leave a void. Whether it is a lift, a different fix or a replacement depends on the cause, so it is not a replacement sign by itself.
- Wide or growing cracks (needs a look first). Cracks wider than 1/4 inch, cracks that widen each season, or cracks where one side sits higher than the other mean the base or soil is moving. Patching the surface will not stop that, so the cause comes first.
Resurfacing over a failed slab is throwing good money after bad. We will tell you so at the site visit, even when the answer is a bigger job for us.
The middle case: a patio that sank in one spot
Sometimes only part of the patio has settled. If the rest is sound, lifting can be the answer. Lifting pumps material through small drilled holes to fill the void and float the slab back to grade. The two materials are a sand-and-cement slurry (mudjacking) and expanding polyurethane foam (polyjacking). Mudjacking vs polyjacking explains the difference. Lifting is usually a smaller job than a tear-out, so it deserves a look before you replace.
How to check your own patio
You can do a first pass yourself:
- Tap the surface. Solid and ringing is good. Hollow sounds mean trouble.
- Look at the cracks. Hairline and stable is fine. Wide, growing or uneven is not.
- Check the slope. After rain, does water run away from the house or sit and pool?
- Check the level. Look for a corner that has dropped or heaved.
Trouble signs mean the slab needs a proper look, and some point toward replacement. A rough surface on an otherwise flat, tight slab points toward resurfacing. A site visit settles which one you have.
What drives the cost either way
We do not publish flat rates, because two patios of the same size can be very different jobs. For resurfacing, the cause of the damage, the condition of the base, the method and the size set the cost. For replacement, the finish, truck access and the grading and drainage under the slab set it. See what drives the cost of repair and resurfacing and what drives the cost of a new concrete patio. The honest way to get a number is a free written quote after a site visit.
Protect whichever fix you choose
Whether you resurface or replace, the same habits keep the surface alive. Keep de-icing salt off it, use sand for grip, and seal it before winter. Sealing slows water and salt from soaking in, which is what drives pitting and scaling in this climate.
Get a straight answer on your patio
Not sure which side of the line your patio is on? We will come look at it, check the base, the level and the slope, and tell you plainly whether it needs resurfacing, lifting or replacement. Read about concrete patios or concrete repair and resurfacing, or request a free written quote. Every repair and every new pour carries our lifetime warranty on labour.
Can an old concrete patio be resurfaced?
Yes, if the slab under the damage is sound. Resurfacing grinds off the weak top layer and bonds a polymer-modified topping to the good concrete below. It restores a clean, even surface without a tear-out. It does not work on a slab that is still settling or whose base has failed.
How thick is a concrete resurfacing overlay?
A polymer-modified topping is thin, about 1/8 to 1/2 inch. That is why it needs a sound, stable slab underneath. A thin layer cannot hold up a slab that is moving.
Will an overlay fix cracks in my patio?
Not on its own. An overlay troweled over a slab that is still moving cracks along the same lines. Hairline cracks on a stable slab are one thing. Wide cracks, or cracks where one side sits higher than the other, mean the base or soil is moving, and the cause has to be dealt with first.
Do you have to replace a patio that has sunk in one spot?
Not always. When a slab sinks, the base failed, not the concrete. A settled slab can sometimes be lifted back to level by pumping material under it, which is a smaller job than a tear-out. If the base has failed across the whole patio, replacement is the honest call, and we say so at the site visit.