Electrical installation under thermal insulation facade

Hello everyone,
and once again a question regarding the electrical installation.

I want to lead the electrical installation for the upper floor to the technical room in the basement along my exterior facade.
The facade will still be insulated with 10cm mineral wool boards.

My idea would be to use a cable duct about 4-6cm deep and approximately 16-21cm wide, which will later be covered by the insulation.
On the upper and basement floors, one drill hole each would be necessary to lead the cables outside.

Is there anything to consider here?
For example, how many centimeters the insulation must cover such a thing at a minimum to avoid, for example, crack formation, etc.?
Is an ordinary cable duct sufficient here, or are there fire protection requirements because it is installed directly beneath insulation?

Regards
Chris

Can't you discreetly install a small distribution box somewhere for the upper floor? 21x6 cm is quite a lot of cable duct.

Hi, the upper floor will get its own sub-distribution board. Electrically, only a 10² cable should run through for supplying the sub-distribution board. What will be added are coaxial cables (about 5 pieces), network cables (about 14 pieces). Maybe a size smaller would also be enough, for example 160mm wide... But better some extra space than running out of space in the end! My question is more about the basics. That means overlapping cable ducts, fire protection, etc...

If your facade only has the 10 cm mineral wool as insulation, 4 cm of additional insulation would be clearly too little for me. I seem to remember you mentioned something about timber frame construction elsewhere, so there is probably cavity insulation - then everything is somewhat more relaxed again.

I would still consider two options in your case:

Either everything in one installation shaft (which can, for example, be built out as a projection on the facade and properly additionally insulated) – then you might later have the chance to also use this for other purposes, like pulling cables, etc.

Or significantly reduce the cables (e.g. switch at the top with uplink downwards, there are also various approaches for coax), and use a certified system for outdoor installation, such as Fränkische FFKu-ReMo. Depending on the situation, maybe it can be done with a maximum of 3 to 4 pipes. That way you also have something that the manufacturer has tested and approved for such purposes.

You surely know that you are not allowed/should not just lay network and coax cables together with power cables – at least separation strips must be present in the cable duct. However, for heavily loaded cables (such as the connection to floor distributors), I would never come up with the idea to lay them together with network/Coax.

If your facade only has the 10 cm mineral wool as insulation, 4 cm of additional insulation would be clearly too little for me. I seem to remember you mentioned something about timber frame construction elsewhere, so there is probably cavity insulation - then everything is a bit more relaxed again.

The timber frame is on the other side of the building... ;) Here, an extension was built using timber frame construction. The existing building is masonry - 30 cm wall thickness - and will be insulated at the same time (10 cm).
That means my idea would be to remove the exterior plaster as best as possible (it is a very rough plaster), attach a duct, and then have the thermal insulation applied over it.

I would still consider two options in your place:

Either everything in one installation duct (for example, it can be built as a projection on the facade and properly over-insulated) - then you might later have the chance to use it for other purposes, like pulling cables again etc.

I had also thought about something like that. But it seemed very complex compared to the cable duct variant.

Or significantly reduce the cables (e.g. switch upstairs with uplink downstairs, there are also different approaches for coax), and use a certified system for outdoor installation, such as Fränkische FFKu-ReMo. Depending on the situation, maybe it works with a maximum of 3 to 4 conduits. That way you also have something the manufacturer has tested and approved for such purposes.

You mean instead of one large cable duct, several empty conduits and thus also separating the cables somewhat?
I am planning a network cabinet in the basement. From here I want to connect all the outlets. Also the TV wiring. I know that the outlets can be daisy-chained (which is already done today). But my idea was also to connect everything star-shaped from the technical room.

You surely know that you are not allowed/should not lay network and coax cables "just like that" together with power cables - at least separators must be present in the cable duct. But I would never think of combining heavily loaded cables (such as the connection to the floor distributor) with network/coax cables.

I am aware of this. My electrician said that with the intended lengths this is not a problem. We are possibly talking about 4 meters here.
But as mentioned before, it could also be an option to separate power and coax/network via several empty conduits.
That way, the construction will not be so high either!

OK, if masonry, why so complicated? You or preferably an electrician can chisel the cable routes, and (just like inside) install cleanly, plaster over, and then insulate just as easily without weak points, etc.

It would of course still be advisable not to bundle everything together, but (also in consultation with a structural engineer) to plan the chiselings as small as possible and with appropriate spacing.