Facade insulation material selection

Hello everyone,

there is surely already a post on this topic, but I must admit the search didn’t really "work" the way I wanted. So I apologize in advance – please feel free to link any existing posts.

Regarding my concern:
I am currently renovating (complete renovation) a single-family house from the 50s, the masonry is 24cm pumice block – plastered and painted on the outside. The roof and windows have been renewed and insulated/to KfW standard. Decentralized ventilation from Lunos.

I read up on the materials and then got stuck on Neopur.
The plan was WGL032 with 160mm thickness. Unfortunately, the said material contains crude oil; in case of fire, this stuff apparently burns brightly within a very short time (at least before the fire brigade’s permitted response time of 20 minutes) – it also liquefies and drips. However, the advantages are the good insulation value, acceptable price, relatively easy processing (including the use of flush-mounted plastic screw anchors to avoid visible marks later), and that I don’t necessarily have to protect the material from moisture during or after processing.

However, the issue of flammability is troubling me now. I mean – of course, one assumes that my house won’t burn down in the next 300 years. But in the event of a fire, that would be a significant disadvantage, and what worries me most is that the fire spreads so quickly within 5–6 minutes. It already takes 5–10 minutes just to notice a fire (if it’s noticed at all).

Rockwool has an alternative product interesting to me, namely the Coverrock II (however in WGL035) with plaster carrier board. There are also similar flush-mounted anchors for it. The price, however, is twice as high... I can’t say anything about the processing. I have to protect the mineral wool from moisture and plaster relatively quickly. The advantage, of course, is that the material is not or much less flammable and does not drip.

Who among you has already installed something like this themselves, and maybe even has a few years of experience?
Who can recommend material to me?
I do not want to discuss the general pros and cons of façade insulation here. The insulation will come with 160mm thickness regardless (electric external roller shutters with plaster carrier).

As you can see, I am quite worried about the material – sorry for writing so much here. I am very grateful for advice!

Note: I think I typed it in the wrong area UPS

The subforum is already correctly chosen.

Rhenish greetings

Neopor is a variant of EPS insulation that has been mixed with graphite. The graphite particles are supposed to scatter thermal radiation and thus reduce the transport of thermal energy within the material. The thermal conductivity value is therefore slightly lower (WLG 032) than in the usual EPS insulation materials with WLG 035. EPS/Neopor are classified in the European fire classes B1, B2 (DIN EN 4102) (flame retardant/normal flammable) and are approved for ETICS. Mineral wool has fire class A1/A2 (non-combustible/predominantly non-combustible).

Mineral wool/stone wool insulation boards must be protected from rain during installation as ETICS, otherwise they become saturated and lose their insulating effect. EPS/XPS materials absorb virtually no liquid water and can also be sprayed with water briefly. This must be absolutely avoided with mineral wool/StVO by using rain protection until plastering and is, in my opinion, too challenging or too expensive for the installation period.

An interesting alternative are phenolic foam boards WLG 021-024, fire class B2 (DIN 4102-1) C-s1 / s2, d0). They are not yet so widespread but should now be offered by interested ETICS specialist companies.

Besides the usual plastered ETICS, there is of course also the ventilated facade with completely different insulation materials but more complex substructure.

many thanks for your detailed answer. That has helped me a lot. I was aware of the graphite particles, which I also find quite interesting. Was I on the wrong track with the crude oil? It is simply not quite understandable to me how materials like Styrofoam or Neopor (if the oil was processed in them) can be flame-retardant and classified as fire class B1. Ultimately, the EPS system will still be advantageous for me, regarding own labor it just takes me a bit longer for everything. I can’t start plastering two days after the first insulation element... Mineral wool is just too hot for me then. And the processing is also somewhat easier. The phenolic foam boards you mentioned are rather not for me; I informed myself about them but they didn’t really convince me. A ventilated façade is definitely an alternative and maybe I should study it in more detail again. Many thanks

We once had a renovation concept with wood fiber insulation systems [WDVS] on hand. No idea how that relates to your parameters. I think I wouldn't care about the petroleum - much more concerning to me are the fungicides. But well, everyone has their own pet peeves.