ᐅ Use of an unheated basement as a storage room?

Hello,

we would like to improve our single-family house from 2017 and use half of the attic as storage space.

Our roof beams are 10cm (4 inches) wide and spaced 50 to 60cm (20 to 24 inches) apart.
For the counter battens, I was thinking of using pieces measuring 60 x 35 x 200cm (24 x 14 x 79 inches) spaced at 45cm (18 inches).
For the panels, I plan to use OSB boards with a thickness of 22mm (7/8 inch) without tongue and groove, leaving a gap of 1 to 2cm (0.4 to 0.8 inch) between the boards to prevent any mold formation.

Is this setup okay so far, or is there anything else to optimize?

Best regards & thanks

Why use counter battens? Just nail tongue-and-groove boards tightly together directly onto the joists, and you'll have a flat floor that doesn’t even allow for ventilation. That’s how our carpenter did it.

We also used tongue and groove boards. However, we built up our roof beams slightly to create some space between the beams and the insulation...

Nordlys schrieb:
Why use counter battens? Just nail tongue-and-groove boards tightly together directly onto the joists, and you'll have an even floor, although it won’t be breathable. That’s how our carpenter did it.

I do have a vapor barrier, but I thought that if there is still air between the OSB boards and the insulation, I’d be on the safe side regarding mold.

Why Tongue and Groove Boards Instead of OSB

Is there currently no covering on the beams at all, meaning the entire floor up to just below the ridge is open?