Concrete Patios in Southern Ontario: The Complete Guide
Updated October 2026
A concrete patio that lasts in Southern Ontario is a drainage job first and a place to sit second. The slab is sloped about 2 percent away from the house, so rain and spring melt move away from your foundation. It sits on a compacted granular base of 100 to 150 mm and is poured as 100 mm (4 in.) of 32 MPa air-entrained concrete, which is built for freeze-thaw. Foot traffic is fine after 24 to 48 hours, furniture goes on after about a week, and sealing comes at about 28 days. Pick the finish (broom, exposed aggregate or stamped) after the grade, base and access are settled. We pour patios, gazebo slabs and pool decks across Southern Ontario, with free written quotes and a lifetime warranty on labour.
A patio is the simplest thing we pour and the easiest to get wrong. This guide walks through what a good concrete patio takes in Southern Ontario, in the order the work happens, so you know what to ask before you sign anything.
Start with where the water goes
Before finish, size or shape, decide where the water goes. The grade has to move all water away from the house. We set the slope at about 2 percent, roughly a quarter inch per foot, and we check where your downspouts discharge before anything is poured.
This is not a small point; see our basement waterproofing work for what wet foundations involve. If your yard already puddles against the house, the right first step may be regrading, or setting the patio at a higher elevation than you pictured. Good advice here sometimes means a different plan than the one you asked for, and we would rather say so at the site visit than aim water at your basement.
The base under the slab
The slab spreads the load, but the ground carries it. For a patio, we build a compacted granular base of about 100 to 150 mm (Granular A) over firm ground.
When an old slab has to come out first, removal and demolition belongs on the quote as its own line.
A mix built for our winters
We use a 32 MPa air-entrained concrete, an exterior mix rated for freeze-thaw exposure. Ask for the mix by name on your quote.
The standard thickness is 100 mm (4 in.), designed for foot traffic and not for vehicle loads.
Choosing a finish
Finish is where you get real choices, and it comes after the grade and the base are settled.
| Finish | Look | Best for |
|---|---|---|
| Broom | Lightly textured, plain | Grip, the affordable end, everyday patios |
| Exposed aggregate | The stone in the concrete revealed | A textured, decorative surface that still grips |
| Stamped | Pattern and colour pressed to read as stone | The premium look, in one continuous pour |
Broom gives good traction and is the most affordable. Exposed aggregate steps up the look. Stamped concrete is the premium choice: pattern and colour pressed into the slab. We quote whichever you are weighing and explain the upkeep each one signs you up for.
Gazebo slabs and pool decks
A gazebo needs a slab planned for it. Tell us the footprint, the post locations and the anchoring requirements before the pour, so the base, reinforcement, edge thickness and anchors match the structure. Bring the manufacturer’s plan to the site visit and we can quote the patio and the gazebo slab as one scope.
A pool deck is a patio with three extra jobs. It has to grip wet bare feet, so we finish decks in broom or exposed aggregate and not smooth trowel, and any sealer gets an anti-slip additive. It has to drain away from the pool, so water does not run toward the pool.
Access for the truck
Access changes the job more than most people expect. If the concrete truck cannot get near the forms, the crew moves the mix by pump or wheelbarrow, and that labour is real. A fenced backyard with a narrow side gate is a different job from an open lot.
Cure, sealing and timing
For a patio, the practical dates are these:
- Foot traffic after 24 to 48 hours.
- Furniture after about 7 days.
- Sealing at about 28 days.
Most patios take one to two days on site: layout and base work, then forming, pouring and finishing. The pour season runs April to November.
What decides the cost
There is no single price worth printing for a Southern Ontario patio. Two patios of the same size can be very different jobs. The finish, the access, the state of the ground, the drainage and grading work, and whether an old slab has to come out first all move the number. Our guide to what drives patio cost goes through how to read a quote.
Your pre-build checklist
Settle these before you ask for quotes, and ask each contractor the same questions:
- Water: where does rain run today, and where do the downspouts discharge? The slab should slope about 2 percent away from the house.
- Base: does the quote name a compacted granular base of about 100 to 150 mm?
- Mix: does it name 32 MPa air-entrained concrete at 100 mm (4 in.)?
- Loads: will anything heavier than people and furniture sit on the slab, such as a vehicle or a gazebo? Tell the contractor before the pour.
- Finish: broom, exposed aggregate or stamped?
- Access: can a truck reach the forms, or will the mix go in by pump or wheelbarrow?
- Old slab: does one have to come out first?
- Timing: the pour season runs April to November.
Getting a real number for your patio
The honest way to get a real number is a free site visit and a written quote that holds. The number you sign is the number you pay. Union-certified crews do the work, and a lifetime warranty on labour stands behind it. We pour patios across Southern Ontario, from Hamilton to Woodstock and the smaller towns around them. Tell us where you are and what you are picturing, and we will come look and put it in writing.
How thick should a concrete patio be?
Four inches (100 mm) is the standard for a patio that carries foot traffic and furniture but no vehicles. The thickness only works over a compacted granular base of about 100 to 150 mm. If you plan to park a vehicle on the slab or set a heavy structure on it, tell us at the site visit so the slab is planned for that load.
What slope does a concrete patio need?
About 2 percent away from the house, which is roughly a quarter inch per foot. That slope moves rain and melt water off the slab and away from your foundation. A patio poured flat or sloped toward the house sends water at the basement wall, so we also check where your downspouts discharge before the grade is set.
How long before I can use a new concrete patio?
You can usually walk on it after 24 to 48 hours. Set furniture on it after about 7 days, and seal it at about 28 days. Most patios take one to two days on site for base work, forming, pouring and finishing.
Can a concrete patio support a gazebo?
Yes, when the slab is planned for that gazebo rather than treated as open patio space. We need the footprint, post locations and anchoring requirements before the pour so the base, reinforcement, edge thickness and anchors match the structure. Bring the manufacturer's plan to the site visit and we can quote the patio and gazebo slab as one scope.
When can I pour a patio in Ontario?
The pour season runs April to November.