Flaking, Scaling Concrete in Ottawa: Find the Fix to Price
Too few published repair prices to quote a range
Repair prices we found come from one vendor, so this page tells you which quotes to ask for instead of a number. Replacement uses the published new-concrete ranges.
Reviewed 2026-09-30 · how we set these ranges
Pick what you see. Each symptom lists what the sources say it can be linked to, what a contractor should check, the repair routes to ask about, and when replacement becomes the question. It is not a diagnosis.
What are you seeing?
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Thin flakes coming off the top
- What the sources say
- The National Research Council's Building Digest 116 calls surface scaling "perhaps the most easily recognized result of frost damage" and says it is most severe where de-icing salts are used.
- Have a contractor check
- How widespread the scaling is, and whether the slab underneath is sound and not moving.
- Repair routes to ask about
- Patching, resurfacing with a bonded overlay, or partial replacement.
- When replacement comes up
- If the slab is also cracked through, heaving or settling, an overlay will not stop movement from below.
- Published price
- Too few published prices for patching or resurfacing; new broom-finish concrete runs about $9 to $15 per sq ft.
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Flaking on concrete less than a year old
- What the sources say
- Digest 116 says freezing of concrete in the plastic state usually results in permanent damage, even with a single cycle; the Code requires cold-weather protection when the air is below 5 °C.
- Have a contractor check
- When it was poured, the air temperature then, and what protection was used.
- Repair routes to ask about
- Ask the original contractor first, then for a repair or replacement quote.
- When replacement comes up
- Ask the contractor to put the cause and the remedy in writing.
- Published price
- Too few published repair prices.
-
Damage where de-icing salt was used
- What the sources say
- Industry guidance from the Ready Mixed Concrete Association of Ontario advises avoiding de-icing chemicals, especially the first winter, and names ammonium sulfate, ammonium nitrate, calcium chloride and magnesium chloride as de-icers never to use.
- Have a contractor check
- Which de-icers were used and where the damage is.
- Repair routes to ask about
- Patching or resurfacing if the slab is sound.
- When replacement comes up
- Replacement if the damage goes deeper than the surface or the slab is moving.
- Published price
- Too few published repair prices.
Not a diagnosis: a contractor has to see the concrete. Every number above is a published figure or a City or Code rule.
The rules behind this job
Surface scaling occurs mainly on pavements, sidewalks and other horizontal surfaces and is most severe if de-icing salts have been used; air entrainment has a "remarkable effect" in improving frost resistance.
NRC Canadian Building Digest 116 (1969)The 2024 Ontario Building Code standard for exterior flatwork and garage floors is at least 32 MPa at 28 days with a water-to-cement ratio no higher than 0.45. Site-batched concrete for those uses needs 5 to 8% entrained air; ready-mix follows CSA A23.1.
O. Reg. 163/24, Div. B, 9.3.1.6 and 9.3.1.7Since March 1, 2026 the City of Ottawa has required a hardscaping contractor licence for businesses that install or alter concrete pads, patios, walkways, steps, driveways and retaining walls on private property. Licence holders must carry at least $2,000,000 of commercial general liability insurance and give clients the City's Landscaping Education Guide. Ask to see the licence and check the City's list yourself; we do not check it. The Licensing By-law excludes "minor repairs or minor alterations", which it does not define; ask the City whether your repair counts.
City of Ottawa, Hardscaping Contractor Licence; Licensing By-law 2002-189 (By-law 2026-222)
Ask before you sign
- What do you believe caused the scaling, in writing?
- Is the slab underneath sound enough for an overlay?
- Which repair product, and what are its maker's instructions?
More on this work: Concrete Repair
Concrete Pro IQ answers behind this page
Quick answers
Can scaled concrete be resurfaced?
An overlay can renew a worn surface only if the slab underneath is sound; it will not stop a slab that is cracking through or moving. Ask the contractor to say in writing why the base slab is suitable.
Want this done at your place?
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