Exterior wall with ETICS or exterior wall with lightweight plaster?

Hello,

The reason the monolithic walls do not become overgrown with algae lies in the lower U-values of the walls in PRACTICE.

How do you come to that conclusion?

The plaster in the ETICS cools down faster but also warms up faster again.

One is a synthetic resin – the other a mineral plaster. I am not an expert, but I hardly think that 2.5 cm of one would warm faster/slower than that of the other plaster.

By the way, both plasters share the fact that you can apply a fungicide-algicide coating to them; then the "green" side has no chance in the long run.

Best regards from the Rhineland

Hello,


How do you come to that conclusion?

With the same interior and exterior temperature and identical U-value, the same surface temperatures on the exterior shell should prevail. So if algae growth is related to surface temperature then...

One is a synthetic resin - the other a mineral plaster. I'm not an expert, but I hardly think that 2.5 cm of one would warm up faster/slower than that of the other plaster.

Depends on the specific heat capacity of the plasters...

Both plasters have in common, by the way, that they can be given a fungicide-algicide coating; then the "green" side stands no chance in the long run.

Right, but that is considered bad in the eyes of some, while at the same time they fight algae on their terrace and paving slabs with Algenex from Aldi and their weeds with Vorox ;)

With the same indoor and outdoor temperature and identical U-value, the same surface temperatures on the exterior shell should prevail.

That is precisely not the case, because the ETICS wall in the Fraunhofer test series cools down below. They certainly did not compare apples with pears. The basic problem is the lack of storage mass in the Styrofoam wonders. It is annoying that I am not allowed to post the link, but the report should be easy to google ... It also mentions the issue that fungicides are not a cure-all because they are washed out faster on the weather-exposed side than they can even take effect in their soluble form.

Hello Allrounder,

post the link; I’ll take the blame :cool:

Rhineland greetings
Building expert

Yes, and there we are again at the fundamental discussion [WDVS yes or no]...

The document from the Fraunhofer institute has long been known to me...

Hello construction expert,

... fundamental discussion ... no, I really didn't want to start that. Just to present a few facts. That's why I (hopefully) left out my personal assessment.