ConcreteFinderGet Quotes

Concrete curing time chart

Last updated: By ConcreteFinder Research Team

Skip to the calculator

Concrete does not dry, it reacts. Cement and water combine in a chemical reaction called hydration that keeps running for weeks, which is why a slab left to bake in the sun ends up weaker than one kept damp, and why a slab that freezes in the first days may never reach the strength it was specified at. The chart below is the schedule Ontario contractors publish for a normal residential pour. Add a pour date and it turns into calendar dates.

When can you walk on it, drive on it and seal it?

The curing chart

  1. Light foot traffic only

    24 hours

    Stay off the edges, which are the weakest part of a fresh slab and the first thing to chip.

  2. Walk on it normally

    Day 2

    Still no bikes, no wheelbarrows and nothing on castors: a point load on a two-day slab leaves a mark that never comes out.

  3. Basic curing period ends, roughly 50 to 60 percent of strength

    Day 3

    CSA A23.1 Type 1 basic curing is 3 days at 10 degrees or more, or however long it takes to reach 40 percent of the specified strength, whichever is longer.

  4. Drive a car on it, and around 70 percent of strength

    Day 7

    CSA A23.1 Type 2 additional curing is 7 days total at 10 degrees or more and the time needed to reach 70 percent of the specified strength.

  5. Full design strength. Heavy vehicles, and seal it now

    Day 28

    This is when a moving van or a garbage truck is safe, and the point at which a protective sealer should go on.

10 to 25 degrees, the ideal window

Petro Cement in Mississauga names 10 to 25 degrees as ideal curing conditions and points at spring, April to June, and early fall, September to October, as the best windows to pour in Toronto. Inside this range the published milestones apply as written.

Source: Petro Cement (Mississauga)

These are the milestones Ontario contractors publish for a normal residential pour. A thicker slab, a high-early mix, an accelerator or a specified strength above the usual 25 to 32 MPa all change them, and the specification for your pour beats a general chart every time.

What the standard requires, not just what is advisable

Curing in Canada is governed by CSA A23.1, and the Ready Mixed Concrete Association of Ontario publishes the relevant tables with CSA Group's permission. The standard sets out three allowable curing regimes rather than one:

  • Type 1, basic curing. 3 days at 10 degrees or more, or the time needed to reach 40 percent of the specified strength.
  • Type 2, additional curing. 7 days total at 10 degrees or more, and the time needed to reach 70 percent of the specified strength.
  • Type 3, extended wet curing. A wet-curing period of 7 days at 10 degrees or more, and the time needed to reach 70 percent of the specified strength, by ponding, continuous sprinkling, an absorptive mat or fabric kept continuously wet.

Two things follow from that wording. First, the day count is a minimum and the strength gate runs alongside it, so a pour that is behind on strength stays under protection past the third or seventh day. Second, every one of those days is counted at 10 degrees or more, which in a Toronto November means heat and hoarding, not patience.

Cold weather, and why no chart can just add days

CSA A23.1 defines cold weather as a probability of the air temperature falling below 5 degrees within 24 hours of placing, as forecast by the nearest official meteorological office. Once that is the case, protection is mandatory: heated enclosures, coverings, insulation or a combination, holding the concrete at a minimum of 10 degrees for the duration of the curing period, and getting it to at least 7 MPa before it is allowed to freeze. RMCAO also flags the practical detail that matters most on a driveway: corners, edges and thin sections are the most vulnerable and need extra.

What no source in this set publishes is a multiplier, and this page does not invent one. There is no honest way to say cold weather adds a fixed percentage, because the answer depends on the slab's own temperature hour by hour. That is exactly why the standard is written as a temperature requirement rather than as extra days, and why RMCAO points at in-place and maturity testing rather than field-cured cylinders in cold conditions.

At the other end, CSA A23.1 Table 14 caps placing temperature. For a section under 0.3 m thick, which is every residential slab, concrete may be placed between 10 and 32 degrees. Petro Cement in Mississauga names 10 to 25 degrees as the ideal curing window and points at spring and early fall as the best times to pour in Toronto.

Frequently asked questions

How long before you can walk on new concrete?

MCL Concrete says light foot traffic only at 24 hours, and Toronto Concrete Repairs says the surface can be walked on after 24 to 48 hours. Stay off the edges either way: they are the weakest part of a fresh slab and the first thing to chip.

How long before you can drive on a new concrete driveway?

Seven days. MCL Concrete calls it the generally recommended minimum before driving on a new concrete driveway and puts strength at around 70 percent at that point; Toronto Concrete Repairs also says after 7 days. Heavy vehicles wait the full 28 days.

Why 28 days?

Because 28 days is when concrete is specified to reach its design strength, which is why a mix is called 25 MPa or 32 MPa. MCL Concrete puts it at roughly 50 to 60 percent of potential strength at 3 days and around 70 percent at 7, with full curing at 28.

What counts as cold weather for concrete in Ontario?

CSA A23.1 defines it as a probability of the air temperature falling below 5 degrees within 24 hours of placing, as forecast by the nearest official meteorological office. The Ready Mixed Concrete Association of Ontario publishes that definition along with the protection required.

What does cold-weather protection actually require?

Holding the concrete at a minimum of 10 degrees for the whole curing period, using heated enclosures, coverings, insulation or a combination, and getting it to at least 7 MPa before it is allowed to freeze. Corners, edges and thin sections are the most vulnerable and need extra protection.

When can I seal new concrete?

After the full 28-day cure. MCL Concrete says to wait the full 28 days before sealing, and Toronto Concrete Repairs applies a curing compound immediately after finishing and a protective sealer after the 28-day cure, then reseals every 4 to 5 years against road salt.

Sources

Every milestone and every temperature rule above is a figure one of these states. Re-read on 2026-08-25. Dataset July 2026.