Interior and exterior plastering (aerated concrete), what to consider

Hello there!

I have many questions and hope for expert answers.

For the house construction, I have now specified the positions of interior and exterior plaster as my own work. My construction company would apply cold cement plaster in the bathroom and kitchen, and gypsum plaster in the other rooms.

I have done a little reading on the internet myself and, as a layperson, decided on pure lime plaster. The shell is made of aerated concrete (30 cm thickness), and according to the construction company, extra thermal insulation is not necessary.

My cousin is a bricklayer (although he has not worked in this profession for a long time), I want to plaster with him, he can do it, but he prefers to use lime-cement plaster (interior plaster) and mix it himself. I have asked around here and there, and most people said I should use ready-made lime mixtures because many mistakes can be made with self-mixing, and the sand must also be of very good quality (washed...).

Now to my questions about the interior plaster, it should also be said that I only want to paint, not wallpaper anywhere, tiles in the bathroom, of course):

1. Lime-cement or lime plaster (gypsum plaster is actually not an option for me, or is it?)
2. Pretreatment for the aerated concrete before plastering (wetting, anything else? Primer or something similar?)
3. Base plaster on it, one layer? How then to float/smooth (lime finish or something else? (plaster/filler)

Exterior plaster:

4. What for the base plaster?
5. Pretreatment?
6. According to the building description: mineral roughcast plaster, grain size 2 mm, what exactly do they mean by plaster here.
7. Plinth, with cement mortar. I would say: all right.
8. I have heard that today it is no longer a problem to apply the fine decorative plaster (what is it made of only?) "immediately" after the base plaster and not let the house settle for a year. The house is also being built without a basement, if that is important.

Hmm? I can't think of more questions at the moment, but there will surely be more.

I look forward to answers and already say: Thank you very much!!!

Hello,

The shell is made of aerated concrete (30cm thickness), according to the construction company no extra thermal insulation is necessary.

Aside from your other questions, which will certainly be answered here with experiential knowledge: what should 30cm aerated concrete be sufficient for? KfW 85/KfW 70 or more and which technology should be installed?
Kind regards

Hello construction expert!

First of all, thank you for your response. We do not have KfW, we have the standard program, which is necessary. Solar panels will go on the roof, that was still the condition. The building permit was granted without any conditions. I found the following in the building permit:

load-bearing and bracing walls outside and inside:

30/17.5 cm aerated concrete masonry

exterior plaster/exterior wall cladding including insulation and substructure:

mineral scratch coat

What else do you need to know?

Thank you

Hello!

I asked again and the building permit was issued according to the valid [Energieeinsparverordnung 2009], so everything is okay. That works out. I just want to know which plaster is best for the aerated concrete.

Thank you

Does no one have any tips and advice here???

Does no one have any advice or recommendations here???

Bringing this back up again. Any recommendations today? I would like to use hydraulic lime cement on Ytong. For gypsum, just wetting and priming is enough. Is there anything else to consider here?