Hiring a Concrete Contractor in Ontario: A Practical Guide

Driveways versus patios and pads: different demands

A driveway carries vehicle weight and takes the brunt of winter salt, snowplow scraping, and daily freeze-thaw exposure, so it generally needs a thicker slab, properly compacted granular base, and reinforcement suited to vehicle loads. A patio or a simple pad for a shed or hot tub carries far less load and can sometimes use a lighter design, though it still needs a solid base to avoid settling.

• Driveways typically need a deeper granular base and are often reinforced, ask your contractor what base depth and reinforcement they are specifying
• Patios generally allow more flexibility in finish, exposed aggregate, stamped patterns, and broom finish all show up more often here than on driveways
• Pads for structures like sheds or hot tubs need to be sized and reinforced to the actual load they will carry, confirm this with your contractor rather than assuming a standard slab will do

Ask your contractor to explain the base preparation for your specific project rather than accepting a generic description, since a driveway and a garden patio should not be built to the same specification.

Forming: the step that decides the finished shape

Forming is the process of building the wooden or metal edges that hold wet concrete in its intended shape and level before the pour. It sounds like a minor preparatory step, but a poorly set form is one of the more common reasons a finished slab ends up uneven, off the intended slope, or draining water toward the house instead of away from it.

1. 01

   Grading and slope

   Forms should be set to direct water away from your foundation, generally with a gentle, consistent slope, confirm this was checked with a level, not eyeballed.

2. 02

   Base compaction

   The granular base underneath should be properly compacted before forms go in, a soft or uneven base under the forms leads to settling later regardless of how good the concrete itself is.

3. 03

   Expansion gaps at fixed structures

   Where the new concrete meets your house foundation, garage slab, or existing walkways, a gap or isolation joint is generally needed to allow independent movement.

It is reasonable to ask to see the forms and base before the pour happens, most contractors are used to this and it costs nothing to check that the slope is directing water the right way before it becomes permanent.

Curing time and why rushing it causes problems

Concrete does not simply dry, it cures through a chemical reaction that continues for weeks after the pour, even though the surface feels hard within a day or two. Foot traffic is generally fine after a few days, but full vehicle weight on a new driveway typically needs considerably longer before the concrete has gained enough strength to handle it without surface damage.

Weather affects curing directly. Concrete poured in hot, dry conditions can cure too quickly at the surface and crack, while concrete poured in cold conditions needs protection from freezing before it has gained enough strength. A contractor experienced with Ontario's seasonal swings should be able to explain how they adjust their approach depending on when your pour happens.

Control joints and why their spacing matters

Concrete shrinks slightly as it cures and continues to expand and contract with temperature changes for its entire life. Control joints are intentional grooves cut into the surface that give the slab a planned place to crack, rather than letting it crack randomly across the visible surface. Getting the spacing and depth of these joints right is one of the more technical parts of a good concrete job.

• Joint spacing generally needs to relate to the thickness of the slab, a common rule of thumb ties joint spacing to a multiple of the slab thickness
• Joints are typically cut soon after the pour, timing matters, cutting too early or too late reduces how well the joint controls cracking
• A driveway with no visible control joints, or joints spaced unusually far apart, is more likely to develop random surface cracks over time

If a contractor's quote does not mention joint layout at all, ask about it directly. It is a normal, expected part of any concrete scope of work and worth confirming before the pour, not after cracks appear.

Sealing and ongoing protection

Sealing is not strictly required for a concrete surface to function, but in Ontario's climate it makes a real difference to how well a driveway or patio holds up against winter salt and repeated freeze-thaw cycling. A sealer helps reduce how much water and de-icing salt penetrate the surface, which in turn reduces surface scaling and pitting over time.

• New concrete generally needs to cure for a period before the first sealer application, ask your contractor for their specific recommendation
• Sealer typically needs reapplication every few years depending on traffic and exposure, get a maintenance recommendation in writing
• Avoid calcium chloride based de-icers on new concrete in its first winter or two if your contractor advises against it, since some de-icing products are harder on new concrete than plain sand

Sealing is a smaller cost relative to the whole project and is one of the more effective things a homeowner can do to extend the life of a driveway through Ontario winters. If sealing is not included in your quote, ask what it would cost to add and whether your contractor recommends a specific product for the finish you chose.

Freeze-thaw cycling: the underlying challenge in Ontario

Most of the concrete problems specific to this climate trace back to freeze-thaw cycling, water gets into tiny pores or cracks in the concrete surface, freezes, expands, and gradually breaks the surface apart over repeated cycles each winter. A properly built, properly cured, and properly sealed slab resists this far better than one where any of those steps were rushed or skipped.

This is also why the base preparation underneath the slab matters as much as the concrete itself. A well-compacted granular base drains water away rather than holding it against the underside of the slab, which reduces how much moisture is available to freeze and heave the concrete from below. When comparing quotes, ask each contractor directly how they prepare the base and how they expect the finished surface to perform through repeated Ontario winters, and see our homeowner guides for other seasonal maintenance guides relevant to your project.