Barn floor - Newbie in trouble

[colinh]

Please excuse my ignorance but after reading the website I am still a bit confused. I want to lay a concrete floor in a small stone barn. The size of the slap will be approximately 7m by 6m. Luckily the dirt floor was dug out by the previous owner (he wanted additional headroom for some machinery) and is approximately 400mm below the required finished floor level. The barn will be used as a general workshop/store and there won’t be anything heavier than my land rover in it.

I was thinking 200mm of hardcore, dpc and then 200mm concrete.
How do I ensure that the slap is all at the same correct level. If the walls were not already there I can imagine it would be easier (plank longer than the shuttering with a sawing motion??).

Should I use a plank all the way around the outside could this just be left in place afterwards or should it be removed if so what should I fill the gap with. If it does need to be removed how is it propped up to ensure it is at the correct level

Is the dpc trimmed to the finished floor level on completion.

[seanandruby]

Place membrane on the floor and fibre board or similar around the edges. build a shutter for two separate slabs say 2 metres or 2.3 meters depending on which way they run (6 or 7) pore these two so you can use shutter and fibre board to screed to and finish, then next day strike shutters and pore infill. if you want to pore in one go use screed rails ie timber or scaffold boards.