commercial camper / false floor what floor though ?

well my camper / false floor is underway , the frame work is in 2 'sections' with space to store the spare section when not in use at the end by the bulkhead, everything just drops together will use nuts / wing nuts for speed, going to leave one side up all the time for storage underneath , and have the floor with a hinge in so it can flap over when needed, it needs to support weight though , currently the 'gap' is 60cm ish both ways so what ply should i use to bridge the gap? or should i put another bar in ? would 6mm ply be ok or should i use 12?

I would not use 6mm it will be far to weak.

I would go for 12mm but you may get away with 9mm. It all depends on the quality of the ply as the market is flooded with cheap Chinese ply that delaminates easy, goes mouldy at the first sign of dampness and stinks and makes your eyes water if in a confined space like a vehicle.

A mate of mine ply lines vans for a living and he has had great trouble avoiding the Chinese crap and nearly lost a big contract over the smell it produces. You cant beat good quality birch ply but it will cost more.

thanks ill go to wickes , i think for the hassel ill put another support bar in the middle , i dont want to go to thick really for weight / price reasons ply is not cheap !