Concrete Pad Cost in Ontario: The Eight Drivers in Order, Thickness by Use, and When a Box Needs No Pad at All

Reading Time: 11 minutes

The eight cost drivers, in the order they move the number

Every concrete pad quote in Ontario is the same eight lines in a different order, and the buyer who knows the order can read a quote in a minute. Area comes first, because everything else is priced per square foot or per cubic metre. Thickness comes second, because a garage floor at 125 millimetres uses close to forty percent more concrete than a shed base at 90, and the ready-mix truck bills by the cubic metre. Base preparation is third and the most underpriced: clearing, grading, excavating the topsoil, compacting the subgrade and laying a gravel base for drainage, which on the clay that underlies most of southern Ontario is the line that decides whether the pad is level in ten years. Reinforcement is fourth, mesh or rebar and the forms that hold the pour. Access is fifth: a truck that can back to the forms pours in an hour, and a back yard the truck cannot reach needs a pump or a line of wheelbarrows, and both are separate lines. Finish is sixth, a broom finish being the baseline and stamped, exposed-aggregate or coloured work adding a fifth to two-fifths on top. Season is seventh, with the shoulder months cheaper and winter pours needing blankets and heat. The ready-mix minimum is eighth: a small pad that needs less than a truck’s minimum load pays a short-load fee that makes the concrete itself the least of it. Labour runs through all eight at a third to a half of the total. We are a container yard in Brantford, not a concrete contractor, and we see this list from the other side every week, because the stone pad a container sits on is what most of our buyers pour instead of concrete.

Thickness by use: shed, garage, driveway, shop

Thickness is set by what will stand on the slab, and the trade’s rule is plain. A light patio or a shed base is 90 millimetres, about three and a half inches, which carries a garden shed, a bunkie or a hot tub on a properly compacted base. A garage floor or a driveway is 125 millimetres, five inches, because a vehicle’s wheel is a point load and a slab that thin at the edges chips and cracks under it. Commercial floors run 150 and industrial or warehouse floors 200, for forklifts and racking legs. The temptation is to pour a shed base at four inches and park a car on it later, and the crack that follows runs from the door to the drain. The other temptation is to pour a garage floor under a building that will never see a car, which is the cost of a driveway for the sake of a workbench; the workshop buildings guide sizes the floor by the machines that stand on it, and a woodworker’s cast iron is happier on a 125 slab than a 90, while a hand-tool shop is fine on the thinner pour. The detached garage reality check’s slab chapter is the slab conversation with the permit, the frost edge and the calendar attached.

The base under the concrete: where Ontario pads fail

The concrete is the part of a pad the buyer can see, and the base is the part that decides how long the buyer likes it. Southern Ontario sits on clay and clay loam that hold water, heave when that water freezes and settle when it drains, and a slab poured on scraped topsoil rides that movement until it cracks. The base that stops it is boring: strip the organics, cut to grade, compact the subgrade, lay 100 to 150 millimetres of three-quarter crushed stone in lifts and compact each lift, and give the pad somewhere to drain. On soft or clay-heavy ground the guide’s word is stabilization, which means more stone, sometimes geotextile under it, and sometimes a contractor telling the buyer that the spot is wrong. That base is priced as excavation, haul-away, stone by the tonne and a compactor by the day, and it is the line that a low quote leaves out. It is also, almost exactly, the pad a container needs on a rural lot with the concrete left off: stripped, stoned, compacted and drained, and then four blocks instead of a pour. Levelling and shimming a box on that base is the rest of the job.

Reinforcement, edges and frost

Reinforcement does not stop concrete cracking; it holds the crack together so the slab stays a slab. Welded wire mesh in the middle of a 90-millimetre pour is the shed standard, and rebar on chairs is the garage and workshop standard, with more of it in the thickened edges where the wheel loads and the wall loads land. The edge is where an Ontario slab meets frost: a floating slab with a thickened perimeter rides the ground as one piece, which is the accessory-building answer, and a slab on frost walls that reach below the frost line is the house-and-garage answer, and the difference is a day of excavation against a week of forming and pouring. The frost line in southern Ontario runs deep enough that the frost-wall version is a foundation job with a permit and an inspection, which is the single sentence on paperwork this page needs. Frost protection on a winter site is the same physics applied to a box, where the answer is to keep the base drained rather than to chase the frost line, and the Sonotube pier poured below frost is the container’s version of the frost wall when a lot needs one.

Access, pumps, short loads and the season

Three drivers have nothing to do with the pad and everything to do with the lot. Access first: a ready-mix truck is heavy and long, and if it cannot back to the forms the concrete moves by pump, which is a separate rental with its own minimum, or by wheelbarrow, which is labour by the hour and a pour that takes all morning; a back yard behind a house on a forty-foot lot is a pump job, and the quote should say so. Short loads second: ready-mix plants bill a minimum and add a short-load fee below it, so a small shed pad pays for concrete it does not use, and the buyer with two small pads to pour saves real money by pouring both the same day. Season third: the guide’s cheaper months are the off-peak ones, and a winter pour in Ontario needs heated blankets, sometimes hot water in the mix, and a contractor willing to babysit it, while a June pour books three weeks out. Finish sits beside those three: a broom finish is the baseline, a hard-trowelled or sealed floor for a shop costs more, and decorative work adds a fifth to two-fifths. The tilt-deck’s own access rules are the container version of the truck problem, measured in metres of straight approach rather than in pump hoses, and a lot a concrete truck cannot reach is usually a lot our truck cannot reach either.

How to read a concrete quote

A good concrete quote is eight lines and a drawing; a bad one is a number per square foot. The lines are excavation and disposal, stone and compaction, forms, reinforcement, the concrete by the cubic metre at a stated thickness, placement including any pump, finish, and cleanup, with the season’s premium and the short-load fee shown if they apply, and the drawing shows the thickness, the thickened edge and the base depth. The number to check first is the cubic metres: area times thickness plus a margin for an uneven base, and a quote whose cubic metres do not match the stated thickness is a quote for a thinner slab. The second is the base: depth of strip, depth of stone, number of lifts. The third is what is not there: the vapour barrier under a shop floor, the anchor bolts or the sleeves for a building that will be bolted down, the control joints that decide where the slab cracks, and the sealer, the way a container quote should show the grade, the delivery and the blocks in writing, which the price-and-grade ladder lays out. The way a container quote breaks down is the same discipline applied to steel, where the lines are grade, size, distance and modifications, and where the first question is likewise whether the number includes the delivery.

When a pad is the wrong base

A concrete pad is the right base for anything with wheels, anything with machines on it, anything that will be bolted down, and anything the owner expects to stand for thirty years in one spot. It is the wrong base for a building that might move, a lot the truck cannot reach, a season that does not allow a pour, a budget where the hole and the short-load fee outrun the building, and a use the pad will outlive: a shed pad in a back corner is the most permanent thing on most lots and the hardest to remove. The alternatives are a compacted stone pad, which is the concrete pad’s base without the concrete, drained and level and reversible; deck blocks or patio stones on a stone bed for the lightest sheds; and piers, Sonotube or helical, for buildings that need to sit above grade or below frost without a slab. The wood shed guide’s base chapter sorts those for sheds, where the base decides how long the walls stay square, and the storage buildings market map says what goes under each of the six families a buyer can put on a lot.

Containers and concrete: what a box actually needs

Here is the part we know from delivering thousands of them: a shipping container does not need a concrete pad. It is a steel box with a floor of marine plywood on steel cross-members and four corner castings that carry its whole weight, so it sits on four points, not on a slab, and what those four points need is a level, drained, compacted surface that will not heave under them. That is a stone pad, stripped and compacted the way a concrete base is, with a concrete block or a pier under each corner casting, and it costs the hole and the stone and nothing else. A slab under a container is money spent on a floor the box already has, and the only reasons to pour one are a shop conversion that wants a slab beside the box for a vehicle, a lot where the ground is so soft that piers are the answer anyway, or a municipality that asks for one, which is rare. Where a box goes on piers, helical piers against a stone pad is the comparison, and where it goes on blocks, a used wind-and-watertight box on four blocks is the cheapest dry, locked floor in the province. What moves the number is size, grade and distance, and the pad is the buyer’s; we sell outright, never rent, and the box arrives on a twenty-footer’s four corner castings or a forty’s, ready to be shimmed level in ten minutes.

The drivers on one sheet

Put the eight drivers on one line each and a buyer can price the difference between two quotes without a calculator. Area and thickness set the cubic metres. Base sets the hole and the stone. Reinforcement sets the steel and the forms. Access sets the pump. Finish sets the trowel. Season sets the premium. The minimum sets the short-load fee. Labour is a third to a half of all of it, which is why a contractor’s schedule and a lot’s access move the number more than the mix does. The buyer who wants to cut the cost cuts it at area, at finish and at the calendar, and never at the base, because the base is the one line that cannot be added later. The container shed weighed against the traditional shed is where the base line decides the whole comparison, since one of the two needs a pour and the other needs a hole.

The concrete pad checklist

A pad priced that way costs what it should and lasts as long as the building on it. The buyer who understands that the hole is the investment and the concrete is the finish reads the next quote correctly, and the buyer whose building is a steel box keeps the hole and skips the concrete altogether.

Reach Van Blanc in Brantford

We have been supplying shipping containers across Ontario since 1995. Our yard is at 90 Morton Avenue East in Brantford, and we deliver right across the province with payment on the day of delivery. No deposit, no upfront wires, no chase-the-paperwork.

Van Blanc Ent. Inc., 90 Morton Ave E Unit 1B, Brantford, ON N3R 7J7, 519-754-6844 (cell) or 1-888-509-6658 (toll-free).

If the pad quote made the building look small, call with what is going on it and your postal code, and we will tell you on the spot whether a box on a stone pad does the job and which boxes are on the ground. Worth the drive for unbeatable quality, family customer service with 30 years of experience.

Related Reading

• Gravel Pad for a Shipping Container
• Helical Piers vs a Pad for a Container
• Sonotube Pier Foundation for a Container
• Building a Detached Garage in Ontario
• Wood Sheds in Ontario: The Honest Guide