Project guide
Building a patio, including large-format slabs
A patio is the job where the format decides everything. Small pavers are a laying job; twenty-four inch slabs are a lifting job, and the two are planned differently from the first load of stone.
TYPICAL 300 SQ FT · 4 DAYS · BASE 8–10 T
The sequence
How the job actually runs
In order, with the tool each stage needs. Skip a stage and it comes back as the stage after it.
- 01
Locates
Free, legally required, five business days. A patio against the house sits over the services.
- 02
Set the grade
Slope away from the building, roughly an inch every eight feet. Decide it now; you cannot add it later.
- 03
Dig out
Six inches of base plus bedding plus the slab. Deeper if a hot tub is going on it — say so before you dig.
- 04
Base in lifts
Two lifts, compacted, checked with a level as you go. A flat base makes a flat patio; nothing later does.
- 05
Bedding
One inch screeded. On large format, use the bedding detail your supplier specifies — some slabs want an open-graded course, not sand.
- 06
Set the slabs
Big slabs go down once. Set them, tap them, and do not slide them — sliding drags the bedding out from under the edge.
- 07
Cut and finish
Cut wet, restrain the perimeter, sweep the joints. On large format the plate does not touch the surface at all.
How big, how long
The three sizes people ask for.
Day counts are for one or two people working at a homeowner’s pace, not a crew’s. Book the longer number.
Typical jobs
| Bistro pad | 120 sq ft | 2 days |
|---|---|---|
| Dining patio | 300 sq ft | 4 days |
| Full entertaining area | 500 sq ft | 6 days |
Tools this job uses
- Toolcat
- Plate compactor — ask us
- Cut-off saw — ask us
- Vacuum lifter — ask us
Anything marked “ask us” is a machine in the yard that is not on the rate card yet. Send the request with your dates and we will tell you what it costs before you commit to anything.
The planner
Your numbers, not an average
Tell it the size and it works out the material, the days and which machines you actually need — including the ones you do not.
Tell it about the job
Square feet. Length times width, near enough.
This is what decides the lifter, and usually it decides against it.
What that takes
300 sq ft patio · 6 in base · two of you
- SURFACE
- 300 sq ft
- BASE
- 8–10 t
- SPOIL
- 11 yd³
- BEDDING
- 1 t
- SURFACE ORDER
- 300 sq ft + 10%
- COMPACTOR
- 1 day
- SAW
- 0.25 day · 1 blade
- LIFTER
- worth it
- BOOK
- 4 days
6 in of base. Walkways and patios. Four inches is the common minimum; six is the honest Simcoe number, because of freeze-thaw.
5.6 yd³ in the ground. Order the top of that range — what you order over what the hole measures — compaction, spillage and over-dig.
9.4 in of dig. Soil bulks when it is dug. The pile is always bigger than the hole. You will want a bin.
1 in screeded concrete sand. Screeded bedding sand. Thicker sand does not fix a low base — it becomes the low spot.
Extra pavers for cuts and breakage. Five per cent on a plain rectangle, ten with curves.
2 lifts of 4 in. Maximum depth of one compaction lift. An eight-inch base is two lifts, not one pass.
About 42 lineal ft of cuts. Per 14-inch general-purpose segmented blade, cutting concrete pavers. Clay brick, granite and rebar cut this down hard.
About 67 lb a piece — a two-person carry. Alone, or a long carry from the driveway, take the lifter.
Dig 1 · base 1 · lay 3 · cuts 0.25, less the overlap between them. Laying at 140 sq ft a day, two of you.
Estimates from average jobs — ground, grade and weather vary. When in doubt, book the extra day: it is cheaper than a second delivery. And order your stone before you book the machines.
The tools, and the ones you can skip
| Tool | Verdict | Days |
|---|---|---|
| Toolcat8 tonnes in and 11 yards out. That is the whole reason to have one on site. | Needed | 2 |
| Plate compactor2 lifts, four passes each. Compaction is never the bottleneck — spreading is.Not on the rate card yet — ask us and we will tell you what it costs and whether it is free. | Needed | 1 |
| Cut-off sawAbout 42 lineal ft of cuts, 1 blade. Cut wet.Not on the rate card yet — ask us and we will tell you what it costs and whether it is free. | Needed | 0.25 |
| Vacuum lifterAbout 67 lb a piece — a two-person carry. Alone, or a long carry from the driveway, take the lifter.Not on the rate card yet — ask us and we will tell you what it costs and whether it is free. | Worth it | 2 |
From experience
What people get wrong
Sand-setting large-format slabs like small pavers.
Follow the supplier's bedding detail. Large format on plain sand rocks within a season.
Running the plate over finished slabs.
Protective pad on regular pavers; on slabs over about eighteen inches, no plate at all.
Two people walking a heavy slab into place.
Over about a hundred pounds a piece, two people is not the answer. That is the lifter's job.
No fall away from the house.
About an inch every eight feet. A flat patio is a puddle with furniture on it.
Sliding slabs to line them up.
Lift and reset. Sliding ploughs the bedding and leaves a hollow corner.
Before you dig
The parts that are not optional
One sentence and one link each. We rent machines — we do not read by-laws for you, and none of this is legal or engineering advice.
Book your locates first. Free, and it is the law.
Ontario One Call is free, and a locate is legally required before you dig. Submit the request at least five business days before you plan to start — infrastructure owners have five business days for a single address, and there is no guarantee they use fewer. Book it the day you decide to do the job, not the day the machine lands.
Ontario One Call — locate requests for homeownersCut wet, or split instead of sawing.
Cutting concrete pavers dry throws respirable crystalline silica, which Ontario regulates under O. Reg. 833. The control is water suppression or a process that makes less dust — splitting rather than sawing is explicitly the safer route. A paper dust mask is not respiratory protection.
Government of Ontario — silica on construction projects: legal requirements (O. Reg. 833)A protective pad before the plate touches finished pavers.
Running a plate compactor straight onto a laid surface chips corners and cracks faces, and on large-format slabs it does it on the first pass. Use the roller pad or the rubber mat, every time. On slabs over about 18 inches, do not run the plate at all.
Be clear about this
What we do not supply
The machines move material around your site. They do not haul it to the curb and they do not bring it in. Sort this out before you book anything.
- Aggregate deliveryGranular A and concrete sand come from a pit, by the tandem load. We rent the machine that spreads it, not the truck that brings it.
- Spoil removalA bin, or a dump trailer from somebody who has one. The Toolcat moves the pile around your site; it does not take it away.
- Pavers, slabs and blockFrom your supplier, with the cut allowance added.
- GeotextileOver clay, it is the difference between a base that lasts and one that pumps mud into itself.
- Edge restraint and spikesWithout it the field creeps and the first spring shows you where.
- Polymeric sandAnd the patience to sweep it in dry.
- Hand toolsScreed rails, string line, level, rubber mallet, knee pads. Bring your own.
Questions
The ones we get asked
How heavy is a 24 × 24 slab?
Concrete runs about 2,400 kg per cubic metre, which works out to roughly 0.087 lb per cubic inch. A 24 × 24 × 2⅜ slab is therefore about 118 lb, and a 24 × 36 is about 178 lb. Both are past the point where two people is a good plan.
When do I need a vacuum lifter?
Over about fifty-five pounds a piece it is worth it; over about a hundred it is the answer. Under that — a 4 × 8 paver, a 12 × 12 slab — you do not need it, and we will say so.
How deep should a patio base be?
Four to six inches for foot traffic, and six is the number we would use here. A hot tub or a vehicle changes it to a driveway spec.
Can I compact the surface at the end?
On regular pavers, yes, over a protective pad. On large-format slabs, no. The plate finds the unsupported corner and takes it off.
Showing our work
Where these numbers come from.
Anything marked [VERIFY] is trade convention we have not yet put in front of a supplier. It is good enough to plan against and we would rather say so than dress it up.
- [VERIFY] Trade convention — not yet confirmed against a supplier or a published standard
- Normal-weight concrete, about 2,400 kg per cubic metre — the standard value
- Ontario One Call — locate requests for homeowners
- Government of Ontario — silica on construction projects: legal requirements (O. Reg. 833)
Next
Related guides, and where we work
Laying an interlock driveway
The base is the job. The pavers are the part everyone photographs, and they are two of the seven days — get the eight inches under them right and the driveway outlives the house. Read the guide
Rebuilding precast steps
This is the job with the highest injury and breakage risk on the whole list, and it is short. A precast step is five or six hundred pounds of concrete that has to land within a quarter inch of where you want it, once. Read the guide
Renting in Barrie
Inside the flat-rate delivery core — one trip covers drop-off and pickup. Equipment in Barrie
Renting in Innisfil
Inside the flat-rate delivery core — one trip covers drop-off and pickup. Equipment in Innisfil
Tell us the dates. We will confirm by text.
Pick the machines, send the request, and we will handle the hauling.
kempenfeltrental@gmail.com · 7am–7pm, 7 days