Insulate a pumice stone wall with solid wood

I want to try cladding a house wall with solid wood sheet piling in 2 layers.
It consists of 12cm simple pumice stone. In winter, the wall is ice cold...
1. Two times 60mm sheet piling. First layer applied vertically directly onto the masonry. (Each piece of wood is drilled and dowelled to the masonry).
2. Then the second layer of 60mm sheet piling screwed horizontally onto the first layer.
3. Battens 30mm thick applied vertically. This will certainly be sufficient as ventilation.
4. Screw facade cladding onto the battens.

Basically, I am optimistic that this should actually work well.
It would be much easier, however, to first apply battens and then start the wall construction as described above.
With a direct connection of the wood to the masonry, the wood would have to dissipate the moisture to the outside.
If there is battens between the wood insulation layer and the masonry, I fear that water will condense on the wall and, if not ventilated behind, mold could form there.
Ventilating directly at the wall at that point doesn’t seem right. Or am I mistaken? What do the experts think?
I would be very happy to receive some well-founded statements and thank you in advance.

Hi, if you really only have 12cm of pumice stone, put some "real" insulation in front of it if you have the space. A curtain wall could look like this, for example: About 8-10cm thick battens on the pumice stones, with rock wool/mineral wool in between. Then a breathable underlay membrane + battens, then vertical cladding as a bottom/top cladding (e.g. larch). I did something similar and it worked quite well.

Yes, I understand that, but since I work in a sawmill, the insulating material itself costs me almost nothing (reject material) and I know some people with solid wood walls who only report the best, I want to take a path off the beaten track. I don't want any foils, no vapor barriers, etc. I want to work purely with the material wood. I'm just not sure about the construction and hope to get expert advice here. Thank you very much

So the solid wood houses of my sister and my parents (both log houses) actually had only about 12-14 cm of solid wood. That was enough back then (about 20 years ago) to meet the energy saving ordinance. But even then it was about airtightness, so insulation strips between the logs so that no drafts occurred ;-) If you put a (relatively) dense wooden panel in front of the pumice, it will provide some insulation effect. However, the wood must be protected from the outside (constructively always better than chemically) and the dew point must not lie within the wooden wall (this needs to be calculated, but for that the exact values (the thermal transmittance coefficients) of the materials would have to be known ... is this known for the leftover wood?)

Doesn't one need a wood mass that ultimately becomes a self-supporting shell around the house for an insulating effect?

It seems that the OP wants to save money by using inexpensive production scraps. However, I don't believe that this will result in a satisfactory balance in the triangle of forces price <-> insulation effect <-> building physics.

The approach you want can be implemented like that. However, you must be aware that the effect is only marginal. The U-value of the finished wall is still really bad (I just calculated it). You still have cold walls. In addition, you have poor dew point shifting - everything will get wet (calculated with spruce and oak). Whether ventilation is sufficient if the moisture penetrates the masonry, I cannot assess. For that, I am too much of a layman.

P.S. Calculated with airtight wooden layers. Not with gaps etc. Probably somewhat drier then, but with missing insulation effect.