The contractor who did the job was a neighbour. He built my double garage 2 or 3 years before and wanted to bring the pad up to the same level as the garage floor. He said that it would stand up better to frost. Canadian prairie winters. The important part was the rebar. He laid the proper amount of rebar and I got the job of tying them together with the wire twisty things with the hooked tool. He was one hell of a contractor.