Pre-fab Slab To Sit On Gravel?

[Silver1]

Going to get my prefab slab (96 X 96 X 6) delivered next week to my house to sit my new tub on. The area has good drainage with a slight slope away from the tub. Am I ok sitting the slab directly on the ground or is there a need for the gravel under it for a base.

[stomper4x4]

First off your want the ground to be good solid ground. I think if anything you should at least use a little sand to make a nice flat and level place for the slab to rest. This way the slab well be supported evenly everywhere and that well help prevent the slab from cracking. I'm not talking about a thick layer of sand just enough to make a nice flat surface. You could use a 2x4 to screed the sand flat. Gravel would work also and would erode less.

You can leave it just ground but it might be hard to get it perfectly flat.