How to Order Ready-Mix Concrete: Minimums, Short-Load Fees, and the Phone Call

The math for how much concrete you need is the easy part, and the slab calculator does it in five seconds. The part nobody explains is the phone call: what a ready-mix plant will ask, what the truck can and cannot do, and the fees that surprise people ordering less than a full load. This is that part.

When ready-mix is the right call

The crossover point is about one cubic yard. Under a yard, bagged mix is cheaper and you control the pace. Over four yards, hand-mixing is not a real option: you cannot mix and place that much before the first batch starts to set, and a slab poured in visibly separate batches has cold joints at every seam. In between, one to four yards, is judgment territory. A yard is 45 bags of 80 lb mix. If lifting, mixing, and wheeling two and a half tons of material sounds like a bad Saturday, the truck wins even when it costs more on paper.

How the pricing actually works

Ready-mix is quoted per cubic yard, but the quoted rate assumes a reasonably full truck. A full truck carries 8 to 10 yards. Small orders cost the plant the same truck, driver, and fuel, so they recover it two ways:

  • A minimum order, commonly 1 yard, at some plants 2 or 3. Below the minimum they simply will not dispatch.
  • A short-load fee for anything under roughly 4 or 5 yards. Typical is a flat charge per yard the truck is empty. On a 1.5 yard patio order, the short-load fee can approach the cost of the concrete itself.

Neither is a scam; it is the economics of sending a 30-ton truck to deliver a small load. But it changes the decision. Call two or three plants, ask for the delivered price of your exact quantity including all fees, and compare that number, not the per-yard rate, against bags.

What the dispatcher will ask you

Have answers ready for all of these before you call:

  • Quantity. Your measured volume plus 10% for subgrade variation, rounded up to the nearest quarter yard. Coming up short mid-pour is the most expensive mistake in concrete work; the calculator builds the margin in.
  • Mix strength. Asked as PSI. 3,000 PSI covers most residential flatwork; 3,500 to 4,000 for driveways; 4,500 where trucks or freeze-thaw punish the surface. If the plant asks about "sack count" instead, 5-sack roughly corresponds to 3,000 PSI.
  • Air entrainment. In climates with freezing winters, say yes for anything outdoors. Microscopic air bubbles give freezing water somewhere to expand. In mild-winter coastal climates it usually is not needed for a patio.
  • Slump. How wet the mix arrives. A 4 to 5 inch slump places well by hand. Resist the urge to order it soupy so it is easier to spread; extra water is free strength loss.
  • Delivery window and unload time. Plants schedule in windows and most give you a fixed number of minutes of free unload time, often 5 to 7 minutes per yard, then charge standby by the minute. Two extra pairs of hands cost less than truck standby.
  • Access. Where will the truck park, and how far from there to the forms? The chute reaches 12 to 16 feet. Beyond that you are wheelbarrowing (plan one barrow per 2 cubic feet and a plywood runway), or paying for a line pump, which is its own line item but turns a brutal pour into an easy one.

Site prep the truck assumes

A ready-mix truck loaded weighs on the order of 60,000 lb. It will crack a residential driveway it parks on and it will sink to the axles in a soft lawn. Assume it stays on the street unless you know your surface can take it. Before the delivery window opens you want: forms staked and braced, subgrade compacted and damp, rebar or mesh placed on chairs, tools staged (screed board, bull float, edger, groover), and a wash-out spot agreed, since the driver needs somewhere to rinse the chute that is not the storm drain.

Worked example: a 12 × 10 ft patio at 4 inches measures 1.48 cubic yards. With 10% margin that is 1.6, ordered as 1.75 yards of 3,000 PSI, air-entrained, 4 inch slump. At a typical delivered rate plus a short-load fee for the empty 6-plus yards, the truck costs meaningfully more than 67 bags of 80 lb mix, and is worth every dollar of it to most backs. The same job at 5 yards would carry little or no short-load fee.

The mistakes that generate second trips

  • Ordering the measured amount with no margin. The subgrade is never flat. A half-inch low spot across a 12 × 10 slab eats 5 cubic feet.
  • Not confirming total price. Per-yard rate, short-load fee, fuel surcharge, standby terms, and any environmental or wash-out fee. Get the one number.
  • Scheduling a hot-afternoon pour. Heat shortens working time. Morning slots give you the day and the shade.
  • Working alone. A yard and a half is a two-person pour minimum: one on the chute or barrow, one screeding.

Once the quantity question is settled, the rest is preparation. Run your numbers in the concrete slab calculator (or the post hole calculator if you are setting posts), add the margin it recommends, and make the call with the list above in front of you. The dispatcher can tell within one question whether they are talking to someone who is ready, and the ready callers get the good delivery windows.