Sealing Concrete Before Winter in Ontario: Should You, and When?
Updated October 2026
Yes, in most cases you should seal exterior concrete in Southern Ontario before winter. Sealer slows the water and de-icing salt that cause scaling and spalling. Do it in fall, on a dry slab, before the first salt goes down. Wait on a new slab until it has cured, about a month after the pour. If the surface is already flaking, sealing slows the damage but does not undo it. A free written quote can tell you whether you need a reseal, a resurface or a replacement.
Every fall the same question comes up: is it worth sealing the driveway before the snow flies? For most exterior concrete in Southern Ontario, the answer is yes. Sealing is maintenance work, and it protects against the thing that does the damage here, which is water getting into the surface and freezing. This guide covers which slabs need sealing, when to do it, and what sealing will not do.
What a sealer actually does
Winter damage to concrete comes from water. Concrete is full of tiny pores, water soaks in, freezes, expands, and over many cycles the surface flakes. De-icing salt pulls extra water into the surface and makes it worse. A sealer slows that down by keeping water and salt from soaking in as easily. We cover the whole chain in protecting concrete from winter salt damage.
A sealer does not make a slab salt-proof, and it does not repair anything. It slows the clock.
Which slabs should be sealed before winter
- Driveways and walkways that get salt. These take the most punishment, from your own de-icer and from road spray. They are the first candidates. See our concrete driveways for how a driveway is poured to stand up to the climate.
- Patios and steps. Stamped and exposed-aggregate finishes need sealing most.
- A slab poured this season. Not yet. New concrete cures about a month before its first sealer, so seal once that month has passed. Keep salt off it all winter and use sand for grip.
When to seal: the fall window
Fall is the right season because the protection is already in place when the salt and freeze-thaw arrive. Seal on a dry slab, before salt season.
How to tell if the old sealer is finished
Splash some water on the slab. If it beads up, the sealer is still doing its job. If the water soaks in and darkens the concrete, it is worn. For exposed driveways and walks, plan to reseal about every two to three years. Tire tracks and other busy spots wear out first.
What sealing will not fix
Sealing is maintenance, not repair. If the surface is already scaled, pitted or crumbling, a sealer will slow the damage but will not restore what is gone. Read why concrete flakes and spalls after winter to see which kind of damage you have.
- Shallow flaking on a sound slab: clean it up and reseal to protect what is left.
- Rough, pitted surface across a larger area: resurfacing puts a fresh wearing layer on a solid slab.
- Deep damage, through-cracks or heaving: replacement is the honest answer, and a sealer over a failing slab is money wasted.
Get a free written quote
Not sure whether your concrete needs a seal, a resurface or something more? Tell us what you have. You get a free written quote that says what the slab needs, and our lifetime warranty on labour stands behind the work we do.
Do I really need to seal my concrete before winter?
For most exterior concrete in Southern Ontario, yes. Winter damage is a water problem: water soaks in, freezes and pushes the surface apart, and de-icing salt makes it worse. Sealer keeps water and salt out of the surface.
When is the right time to seal in the fall?
In fall, on a dry slab, before salt season starts.
Can I seal a brand-new driveway this fall?
Not right away. New concrete cures for about a month before its first sealer, so seal once that month has passed. A slab poured this season is also the most vulnerable one, so keep de-icing salt off it entirely through its first winter and use sand for grip.
How do I know if my old sealer has worn out?
Splash some water on the slab. If it beads up, the sealer is still working. If the water soaks in and darkens the concrete, the sealer is worn and it is time to reseal. Tire tracks and other high-traffic spots wear first.
My concrete is already flaking. Will sealing it fix that?
No. Sealing slows further damage, but it does not bring back surface that has already come off. Shallow flaking on a sound slab can be cleaned up and resealed. Rough, pitted surface over a larger area usually points to resurfacing, and deep damage or cracking through the slab points to replacement.
Do you seal concrete?
Yes. Sealing is part of our concrete repair work, and small jobs are welcome. Ask for a free written quote and tell us what you have.