Start with the yardage, because it is the one number you can work out yourself
Take the length and the width in feet, multiply by the thickness in feet, and divide by 27. That gives you cubic yards. A four inch slab is a third of a foot thick, so a 20 by 20 pad comes out at 20 times 20 times 0.33, divided by 27, which lands a little under 5 cubic yards. Order about ten percent over whatever you calculate, because some of it always ends up on the ground.
Ready-mix arrives in 10 cubic yard loads, so that same number tells you how many trucks are turning up and roughly how long the day runs. Around eight cubic yards and up, moving concrete by hand starts costing more in labor and in finish quality than placing it with a machine costs to bring. That is not a hard line anywhere. It is where the answer usually flips.
Then walk from where a truck can park to where the forms are
Yardage on its own does not settle it. Go stand where a loaded mixer could genuinely sit, on ground firm enough to hold it, and pace it out to the forms from there. If that walk is short, level and clear, the chute or a few barrow loads will do the job. If that walk takes you round the side of the building, past a latched gate, off the edge of a bank, or over anything that has already been paid for once, then the walk has answered the question and the yardage barely matters.
Hand hauling against hose is a full comparison with a page of its own, and it is worth reading before you commit either way. What matters at this stage is only that the walk is a real input and most people skip it. Standing in the driveway beforehand, a yard always looks smaller than it does with a loaded barrow in front of you for the fourth hour.
What you are pouring decides it more often than how much
Some pours are pump jobs on the strength of what they are, before anybody measures anything. A footing trench has a far corner that no chute reaches, and footers stepped down a bank are ordinary work in this country rather than a special request. A basement floor or an interior slab sits behind a wall that is already standing, so the concrete has to come in through a door opening or a window opening. Poured walls are the same story.
Open flatwork is the other end of it. A driveway on a level lot with hard ground right up to the forms is exactly what a chute was built for. When that is what we are looking at, the estimate says so rather than putting a machine on a job that does not want one.
What a pump does and does not do to the number on your estimate
On our own work there is one price for the job and the pumping sits inside it. You get one written estimate from one crew covering forming, placing, pumping and finishing, because our own operator and hose hand run our own trailer line pump. There is no second company to schedule and no second bill to chase.
The bands published on our cost page are installed prices for finished work. A driveway runs $8 to $12 per square foot installed, and that range is the finished driveway rather than a chute price with a pumping line waiting to be added underneath it. What actually moves a quote up or down within a range like that is its own subject and it has its own page.
If you are pouring it yourself and placement is the only piece you are short on, we do the pumping for you, on your date and around your crew. The machine is never handed off to anybody else. Our operator and our hose hand arrive with it, and your finishers stay on the finish. There is a workmanship warranty on work we pour ourselves, and what it covers is set out on the written estimate you get.
The pours we talk people out of
The pump is ours and it is paid for, so there is no reason to talk it onto a job that does not want it. A couple of yards on flat ground with the truck able to back in is not a pump job. Neither is a corner that a few barrow loads will finish on an otherwise ordinary pour. Steps, a small pad, a length of sidewalk with a short and level walk from the truck: those get placed off the chute and nobody is worse off for it.
If you call about one of those, the estimate will say chute, and it will be a smaller number than the one you were bracing for. Saying that out loud costs us nothing, because the pours that genuinely need the machine are not in short supply around here.
The call that settles it, and what to have in front of you
The honest answer to this question comes out of a five minute phone call rather than a rule. Have these ready and you can usually have an answer on the spot.
- Dimensions and thickness, or the yardage if you have already run it
- What you are pouring: driveway, patio, garage or shop slab, footers, basement floor
- Where a loaded truck can park on ground firm enough to hold it
- What sits between that spot and the forms, and roughly how far it is
- Gate widths, and door or window openings if the concrete is going inside a wall
- The date you are aiming at, so trucks can be spaced against it