Looking for some stable advice ....

OK, PLEASE no more stable jokes permitted after this point ....

We are at the planning phase of an exciting new project, which is installing two internal stables in a barn that adjoins our house.

Unfortunately the third of the barn which we would like to place the stables has a soil floor, so we have thought about hiring a mini digger, taking the cab off, and then digging the floor out some more.

We would like to have a concrete floor, use the back and side walls as they are, and install one central partition dividing the two spaces, then having the doors perpendicular to this, opening out into the central third of teh barn.

I was wondering if anyone could offer any advice on how much aggregate is needed before the concrete is laid? What depth of concrete is needed? Are any metal structures required below?

I understand that it is common practice to lay the partitions on a row of bricks, can I ask why? And is this necessary when erecting partitions made from hardwood inserted into a galvanised frame .... and one more thing .... does anyone know the standard way that these fix into the ground?

Also, any ideas for drainage? Is a 1% fall enough and is it best falling towards the rear or the front of the stables?

SOoooooo many questions I know .... but many thanks in advance!

concrete should be strong enough to take the daily wear and tear of a horse so at least 6"
the reason for the course of bricks is the walls tend to be timber - timber and wet = rot
in our stables we have 2 bricks at front that are removable this allows for hosing the floor when needed
don't level the concrete to much a little roughness gives the horses grip
floor should drain but not sloped too much