Once a pour starts it should not stop unplanned, because the first concrete keeps stiffening while you wait. The clock runs from batching, so it is already running before the first truck arrives. This checklist is for the site engineer, foreman or owner-builder with a pour booked. It covers ordering ready mix concrete and mixer trucks in three stages: before you order, the day before, and during the pour.
How do you work out how much concrete to order?
Multiply length by width by depth, all in metres. The answer is in cubic metres (m³).
For example, a slab 10 m long, 6 m wide and 0.15 m thick is 10 × 6 × 0.15 = 9 m³. That is the theoretical volume.
Real pours use more. An uneven base takes extra concrete to fill low spots. Formwork can move slightly. Some is spilled or left in the pump and hoses. Ask your engineer what allowance to add for your job, and write it next to the calculation so everyone uses the same number.
Common mistakes and fixes:
- Measuring the drawing, not the site. Check the levels of the prepared base before you order.
- Forgetting beams, footings or steps that are poured at the same time. Add each part separately, then total them.
- Mixing units. Convert centimetres and millimetres to metres first.
Ask the supplier how much one mixer truck carries. Divide your volume by that figure to get the number of loads, and round up.
What does the ready-mix supplier need when you order?
A supplier cannot quote or deliver from "some concrete for a slab". Have these ready, taken from your drawings and specification:
| Detail | Why it matters |
|---|---|
| Strength grade or specification | Sets the mix design. Your engineer decides it. |
| Workability (slump or flow class) | Sets how the mix flows, and whether it suits pumping. |
| Maximum aggregate size | Must suit the reinforcement spacing and the pump line. |
| Admixtures or special cement type | Only if the engineer requires them. |
| Volume | Your calculation, with the agreed allowance. |
| Delivery address and time | Pin the site on a map if the gate is hard to find. |
| Pumped or not | Pumped mixes are often designed differently. |
Do not guess the grade or workability to get a faster quote. The specification sets them, and a wrong mix can mean rejected concrete.
How do you match truck arrivals to how fast you can place?
The delivery rate should match the rate your crew can place and compact. Two things go wrong when it does not.
If trucks arrive faster than you can place, they wait on site and the mix ages in the drum. If they arrive too slowly, the earlier concrete stiffens before the next load goes against it. That can leave a cold joint, a weak line through the finished work.
For example, say your crew can place about 10 m³ an hour and a truck carries 6 m³. Then one truck every 35 minutes or so keeps the face moving. Your real figures will differ, so ask your foreman for an honest placing rate and share it with the supplier.
Decide the gap between trucks, not just the first arrival time. Ask the supplier to confirm the plan and give you a dispatcher phone number for the day. If you use a pump, its output limits your rate too. For choosing one, see boom pump vs line pump.
What must the site have ready the day before?
Most delays on pour day come from the site, not the plant, so walk the site the day before with this list.
- Access. A loaded mixer truck is heavy. Check the route, the ground, the turning space and any height limits such as overhead cables or gate frames. A truck stuck at the gate stops the whole pour. Keep trucks and any pump boom well clear of overhead power lines, and have someone direct reversing trucks. Follow the site's own safety rules.
- Formwork and reinforcement. Fixed, braced, cleaned of debris, and inspected and signed off by the engineer or the client's representative where required.
- Pump, if used. Position agreed, outriggers on firm ground that the pump operator has accepted, line route clear.
- Crew. Enough trained people to place, spread, vibrate and finish, plus someone directing trucks.
- Vibrators. Working units, spare heads, and a standby generator or power supply. Hire concrete vibrators early; a breakdown mid-pour can stall the work.
- Lighting, water and finishing tools if the pour may run late.
- Samples and testing. Agree who takes test samples, and have moulds and a place to store them.
Tip. Call the supplier and the pump operator the day before to reconfirm times. A short call is cheaper than an idle crew.
What do you check when the first truck arrives?
Treat the first truck as a test of your plan.
- Meet the truck and direct it to the discharge point.
- Check the delivery ticket. Do the grade, workability, volume and admixture match your order? Note the batching and arrival times. The specification may set a time limit from batching to discharge, so ask your engineer what applies.
- Look at the mix. Ask whether the specification requires a slump or flow test on delivery. If it does, test before discharge and compare with the limits the engineer gives you. Do not rely on appearance alone. If the mix looks different from the order, or too wet or too stiff, hold the load and speak to the engineer before it goes into the formwork.
- Take samples as the specification requires. Test samples, such as cubes or cylinders, are taken during the pour for later strength testing. The specification usually names who takes them, so settle this before the day.
- Place and compact in layers, as the engineer directs, and record each load against the ticket.
Watch out. Do not add water on site to make concrete easier to place or pump unless the engineer has approved it. Extra water weakens the hardened concrete. If the mix is too stiff, call the engineer or the supplier.
How does Saudi heat change the plan: timing, curing and delays?
Heat speeds up stiffening and drying. Requirements differ by project, site owner, municipality and insurer, so confirm yours before mobilising.
The usual measures in hot weather are:
- Pour early in the day or at night, when the site rules allow it.
- Keep trucks from queueing in the sun. Stagger arrivals and use the shade.
- Start curing promptly after finishing, as the specification requires.
- Ask the ready-mix supplier what they offer for hot-weather pours.
Plan for delays too: traffic, a closed road, a slow gate. Tell the supplier your latest acceptable time, and agree what happens if a truck is late. For working hours across the year, see planning equipment around Ramadan and summer. Dust and heat also affect your machines, covered in protecting machines from dust, sand and overheating.
What do you do at the end: leftovers, washout and curing?
Decide these before the first truck, not when the last one arrives.
- Leftovers. Order carefully, but know where a small surplus will go. Do not dump it where it blocks drainage or access.
- Washout. Trucks and pump lines need washing. Agree a washout area with the site owner or client, away from drains and neighbours, and follow local rules on disposal.
- Curing. Keep it going for as long as the specification says, and name one person responsible.
- Records. Keep delivery tickets, sample records and times in one file.
For the wider picture of the machines on a concrete job, see concrete equipment explained.
How to do this on Maedah
Maedah lists the machines; the concrete itself still comes from your ready-mix supplier, so agree the grade and timing with them as above. For concrete mixer trucks or a concrete pump, post one request with the machines, the city, the site on a map, the pour date and start time. Note the volume, pump route and access limits.
Sealed quotes line up side by side. Compare what is included, response time and rating, and use the chat tied to a quote to settle arrival gaps. Agree price and payment with the supplier directly; Maedah does not process payments.
