13x11 Metal shed floor board OSB or Plywood?

[spader]

Just set up a metal shed 13x11 on the slab in the corner of the garden.
It came with the floor kit, and it is all installed. What would be better for the floor board on the floor kit in the shed?
I can think of OSB or plywood. Which would be better for longer lasting floor board?
Are there better option than those two?

 

[Why Not Indeed]

You need to keep moisture to a minimum in a metal shed because it will form condensation on the inside and "rain" down on the contents. So at a bare minimum you want a DPM between the sheet of timber and the slab. The timber wouldn't be doing much "work" here so I doubt there would be much difference between ply and OSB. Ply would be easier to keep clean.

 

[spader]

The metal shed will be kept open doors as often as possible for ventilation, and some sort of wood stove or gas stove will be running in the shed to dry out the space. Also planning to cover the roof with some sort of tarp to trying insulate from the elements.

Height of the metal floor kit which looks like galvanised metal frame is about 1 inch, so it will be the gap between the slabs and the floor board.
As your suggestion I would go for 18mm hard wood ply for easy sweeping and brushing the floor.

 

[foxhole]

Any gas appliance will increase humidity as moisture is produced when burning gas.

 

[big-all]

as it has its own floor already 12mm ext ply will be more than enough as its reinforcement rather than replace
and iff you are often going to get the floor wet with open doors [by accident ]make sure you have a full sheet covering the door area with no joints so when it blows it one sheet to replace not two
there is a reasonable chance any damage may only go back perhaps 200-400mm so plan the odd strip at the door end as 13ft may leave 1ft/304mm to fill ideal for replacement if at the door