ᐅ Sealing cable penetrations in exterior walls?

i_b_n_a_n schrieb:

Let the builder handle that to preserve the warranty. If you make a mistake there, it can damage the wall (and yes, this does happen).
(...)

I want to remind you again.
Yes, it’s annoying. But take it seriously. If in 5 years the insulation on your wall is rotting and the inspector finds that you installed cables outside yourself and did not seal them properly...

I work in specialist system construction. What do you think we look for first when there is damage at a customer’s site? Exactly, external fault caused by customer tampering with our system. In that case, we don’t pay anything at all...

netzplan schrieb:
Oh great, I’m familiar with those parts for the roof when there is a cable or pipe outlet. That means they could also be used for the exterior wall. (Example Poroton hollow bricks. However, the weak point at the cable outlet between the mineral wool insulation and the exterior plaster still remains

No, not necessarily. For example, if you use fleece-butyl collars from Eisedicht, these can be installed directly on your insulation and then plastered over. This way, the cable can be sealed airtight right at the exit point.

If you really want, you can of course additionally install an aluminum-butyl collar behind on the wall and then insulate over it – this provides double protection.

Harakiri schrieb:

(...) so you have double protection.

And if you don't do it properly because you don't know better... then you have nothing at all 😀

So I asked my energy consultant. You actually only need these parts if you go through the vapor barrier. With a solid wall, that wouldn't be necessary.

netzplan schrieb:

I asked my energy consultant about this. You typically only need those components when going through the vapor barrier. For a solid wall, it wouldn’t be necessary.

Is your energy consultant a structural engineer? Or a retrained cook who could no longer work in their original profession?

netzplan schrieb:

So I asked my energy consultant. You actually only need those components if you pass through the vapor barrier. For a solid wall, this wouldn't be necessary.

Your wall is only partially solid. Behind the plaster, there is an 18cm (7 inch) ETICS made of mineral wool (and an additional plaster base layer in front of that?).
It will deteriorate if it gets damp. So it must be sealed. Don’t just ask an energy consultant—the certificate is completed in three afternoons (this doesn’t mean that all energy consultants don’t know what they’re doing). But here, ask the responsible home builder, as they provide the warranty for the house. If they give written approval for your planned penetration, then everything should be fine.
And almost every wall has some kind of vapor barrier, whatever material it may be. Or am I mistaken here?