suspended timber floor

[petek001]

Hello
So I have an outbuilding outside, I am getting the flooring out due to mould damage to the plywood floor (I have found the leak- it was at floor level!). The subfloor is a suspended timber floor approx 15 cm above a clean, water free concrete base. I am going to insulate in between the joists, but have noticed that there is no ventilation inlet/ outlets. Dp I ahve to do this if there isa moisture free concrete base?
If so, how on earth am i going to do this?
Also can i paint / treat the wooden joists to make them weather resistant?

Thanks in advance

 

[blup]

Cut the timber short of the wall or drop it onto a joist hanger wrapping the end in plastic dpc or treat the ends,