This is not going to be the first time that you hear a story like this, and it definitely is not going to be the last. Concrete contractors make mistakes just like everyone else, the only difference between these mistakes and other mistakes, is that they can cost the contractor a small fortune.
Here's a true story and it actually happened to the person writing the story. I was working on a job that required a lot of concrete, during a construction building boom and I could not get concrete from anyone. I finally called one of the ready mixed companies who delivered concrete to jobs like mine and asked them if there was any chance that I could get any concrete, at any time.
The dispatch operator said that he could give me concrete on a specific day at three o'clock in the afternoon. This is not ever a great time to pour concrete, and most concrete professionals know the risks involved in pouring concrete this late in the afternoon.
I ordered 26 yards of concrete and when the first truck came, it had 10 yards of concrete in it. It looked like I had covered more than half of the job with my first truck and was thinking that maybe I ordered too much concrete. The second truck came and it had 9 yards of concrete in it and by the time it was done, I did not think that I was going to have enough concrete.
By the time the third truck came, it was almost 5 o'clock and by the time this truck was finished pouring its concrete, it looked like I was about two yards of concrete short. These are the kind of things that happen, if you work in the construction business, as long as I have.
I could not get any more concrete from the concrete company, because they were closed. I had to go down to the local home improvement center and get 120 bags of concrete to mix on-the-job with me and two other workers. We finished the job at 11 o'clock in the evening.
I do not really know if I missed figured the concrete or if the concrete company actually shorted me on my concrete, but I do know this, I learned a valuable lesson that day. If you really want to save yourself a lot of frustration, it's always going to be better to order more concrete than you think you will need.