Concrete Patio Fall Prep Before Freeze-Up in Ontario
Updated October 2026
Before freeze-up in Southern Ontario, give your concrete patio four things: a clean surface, a patio that still sheds water, a sealer that still beads water, and a plan to keep de-icing salt off it. Seal on a dry day in fall. A patio poured this season should not be sealed until it has cured about 28 days and should never see salt in its first winter. If the patio needs work, a free written quote tells you what it needs.
A concrete patio is a gentle life for concrete, right up until the first hard freeze. Water gets into the surface, freezes, and the top layer flakes off by spring. Here is what to do before freeze-up, in the order that works.
Clear it and let it dry
Sweep off leaves, soil and debris first.
Then wait for a dry stretch. Sealing in particular is best done on a clean, dry slab.
Check where the water goes
A patio is built to shed water. We set the slope at about 2 percent away from the house, roughly 1/4 inch per foot, so rain and melt move away from your foundation. Before freeze-up, walk the patio after rain and see where the water goes.
Seal it, if it is time
Sealer soaks into and coats the surface so water and de-icing chemicals get in less easily. Less water in the surface means less ice and less scaling. Fall, on a clean, dry slab, is the best time to put it on, because the protection is in place when the freeze-thaw cycles start.
To find out whether you need to, splash water on the patio. If it beads up, the sealer is working. If it soaks in and darkens the concrete, reseal. Plan to reseal every few years, and expect the busiest spots to wear first.
A patio poured this year is a different case. A new slab is sealed at about 28 days, so a patio that is younger than that waits until it has cured. Foot traffic is fine after 24 to 48 hours and furniture after about a week, but the surface is still hardening. See why a first-winter slab is the most at risk for what that means for your first winter.
Plan for salt before the snow
Decide now how you will treat ice on and around the patio, because the bag of rock salt in the garage is the easy choice in January. Salt does not dissolve concrete. It pulls extra water into the surface and lets the freeze do the damage. Shovel early, use sand for traction, and keep salt off a patio that is under a year old. If you must use a de-icer on an older, sealed slab, use the smallest amount that works.
If the patio already needs work
A patch or a coat of sealer will not fix every problem. Resurfacing can renew a rough surface over a sound slab, and repair or replace is the same question a driveway owner faces.
Get a free written quote
If your patio needs work, tell us what you see. We will visit, measure and give you a free written quote that says what it needs.
When should I seal my concrete patio in the fall?
Seal on a dry day, once the slab is clean and dry, and before freeze-up. A simple check is to splash water on the patio. If it beads, the sealer is still working. If it soaks in and darkens the concrete, it is time to reseal.
Can I seal a patio that was poured this year?
Only after it has cured. A new patio can take foot traffic after 24 to 48 hours and furniture after about a week, and it is sealed at about 28 days. If your patio is younger than that, wait. Whatever you do, keep de-icing salt off it for the whole first winter and use sand for grip.
Do I need to do anything about drainage before winter?
Water that sits on the slab can freeze in it. A patio is built with about a 2 percent slope away from the house, roughly 1/4 inch per foot, so rain and melt move away. If you are unsure how yours drains, ask us for a free written quote.
Is it safe to use salt on my patio in winter?
Avoid it. The chloride in rock salt pulls extra water into the surface, so a freeze puts more pressure on the slab and the top layer flakes. Shovel early, use sand for grip, and skip de-icer completely on a patio under a year old.