Laying concrete slab for pre fab garage

[Nitrospud]

Hi, I need to lay a concrete slab for a pre fab garage. The slab will measure 4.2M x 8.7M and is 150mm thick with steel mesh reinforcing. I intended to lay Ready Mix in two or three equal sections to make it more manageable, but have talked to two different companies and both have said they would normally lay that size in one hit. The other reason for sectioning it, is that the long edge is against a fence and therefore tamping can't be carried out from the sides. Any feedback appreciated ??

Steve