Cold roof - Are roof windows necessary for cross ventilation?

That is probably too sluggish for that - especially since condensate can occur quite abundantly and it has to be removed differently.

That's just the way it is

A properly ventilated cold roof has openings at the ridge *and* eaves. How many and their size are specified in the relevant DIN standard.

But I meant a warm roof, which also needs to be ventilated.

I also thought until now that we had a cold roof since it is uninsulated, but it is also not ventilated. In summer it is like an incubator to the power of 10 up there. However, the roof structure shows no signs of rotting away, it is bone dry up there. Should I install ventilation openings now or rather leave everything as it is, because somehow it seems to work?
Do the ventilation holes have to lead directly outside or is it enough if they open into the ventilation layer of the facade? Then I wouldn’t have to cut a hole into the nice new gable side.

Hello dear forum members,
I’m doing some thread necromancy here because it simply fits my question well.
The following roof structure is included in my scope of work description.
Is the roof structure okay like this?

Structure from inside to outside:
Ceiling
- Lightweight panels (Rigips GK 12.5 mm in Q2 quality)
- Substructure
- Vapor barrier
- Rafters with internal insulation
- Folding attic ladder ClickFix 0.7 x 1.20 insulated U-value 0.49
Roof
- Vapor-permeable underlay membrane
- Counter battens, battens and roof tiles

The roof is intended to be used as a storage room (basement substitute) for stuff that is really only needed seasonally (Christmas decorations, suitcases, etc.). I actually don’t want a hotbox in the roof because I don’t always know exactly which things can withstand what kind of heat (suitcases made of synthetic fabric?). And of course I don’t want a dripstone cave.
Do I need any additional ventilation? There is nothing about ventilation grilles in the scope of work description. Would it maybe make sense to move the insulation layer, which is currently above the ceiling of the first floor, up to the roof? How much more expensive would something like that be?

Second question: Since there is currently no load-bearing floor planned, I would have to install (or have installed) a storage floor myself. I was already verbally told that this is basically possible, but the supporting structure is only designed for a permanent load of 80 kg/m². What is best to use there so that not too much weight is already “wasted” by the “floor”? And what happens if a higher point load occurs (you don’t weigh everything you put up there). Will the entire ceiling eventually collapse? Or are there simply cracks?

Thanks and best regards

Tolentino