Installation of insulation for the top floor ceiling (storage room)

Hello everyone,

I am planning to insulate the top floor ceiling 110 sqm (concrete) of the old building built in 1972 on my own.
The duplex has two full floors (ground floor, 1st floor) and a basement.

The 110 sqm shall be covered as follows:

[*]70 sqm not walkable
[*]40 sqm walkable as storage room

All without additional vapor barrier, since I have a concrete ceiling.

Questions:

1) Do I need a vapor barrier because of the concrete ceiling?
2) Which material and thickness can you recommend for the non-walkable and walkable area?
3) In which price range should the insulation material for the two areas be?
4) What should I definitely consider when installing it? Possibly there is a good link with instructions?

Thanks to you all!

Best regards

It is very difficult to make a prediction from the sparse information without drawings. My cure-all is Linitherm, in this case 60mm, but more information is needed.

For non-walkable areas, you can use any wool you like. I used stone wool. 2 x 12cm crossed, to possibly avoid gaps. Nothing on top, then it really doesn't matter with the vapor barrier. For the walkable part, there are various options. From finished panels to completely DIY. What do you have in mind?

Here is a sketch again of how my attic roughly looks:


This is how I imagined it. Whether to buy the elements ready-made or DIY depends on how different the price per sqm turns out for each variant.
There are so many different manufacturers and materials for insulation.

I had considered using WLG/WLS 040 universal felt roof insulation 120 mm thick for the non-walkable part. Laying it crosswise, that comes to about 8 EUR / sqm.

For the walkable part, I had found a composite element made of Styrofoam 035 with a 12mm OSB board (finished product, just single-layered 23 EUR/sqm) OR WLG 035 stone wool boards 120 mm. However, for the latter with double layering, I come to about 50 EUR / sqm.
Can you walk directly on these stone wool boards and put things on them, or should you lay a 19mm chipboard on top with tongue and groove?

What prices per sqm do you come up with for the variants? As cheap as possible would be good.

Thx

LG

Well, you can research prices yourself. You can also take the cheapest wooden beams, for example 12cm high, and fill the gaps. Then cross beams again and fill in. On top goes tongue-and-groove boards and that's it. Labor-intensive, but good. The sawmill offers cheap wood. It can also be reject wood.

Well, I was just interested in what price you / you all came to per QM.

Could you also answer my question whether you can walk directly on the stone wool board or if you definitely have to lay chipboards on it?
By wooden beam height, did you mean 12mm?

The beams shown in the graphic are in the air and not on the ground... There the beams are supported by posts. That means, in principle, I have a free concrete surface as a floor to be covered. Where the posts are, would I have to cut out or something? Here is a photo: