Wallpaper or plaster? Which is better in new construction?

If it should be diffusion-open, then no fleece is used at all, but dispersion silicate is applied directly to the plaster. I find it quite absurd to introduce an organic material, such as fleece and adhesive, into a moisture-regulating wall.

Sure, the painter's fleece does not block as tightly as fiberglass or dispersion paint. But it is still 3-5 times less diffusion-permeable than the silicate paint on the bare plaster.

Sanding (or having it sanded), painting, done.

Thanks for the tip, I will keep that in mind.

How important is maximum diffusion openness? Painter's fleece is also diffusion-open but having the walls plastered and then painted is probably more expensive than having painter's fleece wallpapered, right? The walls would have to be at least nicely smoothed with Q3 or Q4.

Which wall paint should we use with painter's fleece, preferably silicate as well to reduce the likelihood of mold? Of course, assuming good ventilation.

how important is maximum vapor permeability? Painter’s fleece is also vapor permeable but having the walls plastered and then painted is probably more expensive than having painter’s fleece wallpapered, right? The walls would have to be at least finished to a good Q3 or Q4 level

Experts and laypersons who have read a bit about this have been arguing about it for decades. The fact is, your entire wall construction with plaster, filler, primer, and silicate paint will have an sd value of maybe around 0.03 m. With a bit less filler, but with primer, paste, and painter’s fleece, 0.05–0.07 m. According to standards, anything under 0.5 m (yes, 50 cm, no zero missing) is vapor permeable. So you are still miles away from that. Nevertheless, MrDx here will soon be summoning the mold apocalypse. In this extreme, it’s of course nonsense. The majority of people lived or live in tenement houses where walls were properly sealed with dispersion paint and sometimes latex paint, and in most apartments there is no mold. By the way, nowadays most dispersion paints are vapor permeable according to the norm (sd value <0.5 m). Everything else is incidental. There was also somewhere a post where someone calculated how much moisture the wall can absorb (to release it later), and that simply didn’t add up in terms of absolute volumes without ventilation. Unfortunately, I lack the knowledge to provide proof here myself. But maybe with good Google skills you’ll find the text I mean.

Which wall paint should we use with painter’s fleece, preferably silicate, to reduce the likelihood of mold? Of course, assuming good ventilation

Yes, you can use silicate dispersion, it is highly alkaline and already prevents mold growth quite well. To prevent mold, you must especially heat and ventilate. Yes, in my opinion, a high-quality filling is more expensive than having painter’s fleece wallpapered, but it can also be different if, for example, you get filler for free or very cheaply get professional services. Because painter’s fleece itself is of course a cost factor. I claim especially in DIY work the end result is much better because at least I can’t achieve a good result when filling whole walls evenly.

Yes, I also think it's exaggerated and that painter's fleece is probably vapor-permeable.

Everyone I know, whether in rental apartments or houses, hasn't cared at all about how vapor-permeable the wall is, and there is no mold.

Yes, with DIY work, painter's fleece will definitely have a better result than just spackling.

Should I ask again what is cheaper with the painter: painter's fleece or just spackling (if he only uses our spackle? (we got it for free))?

If the walls are only plastered, then small cracks that occur during drying from new construction will also become immediately visible. The painter's fleece would initially cover these.

How likely is it that such cracks will form in the wall? Among all acquaintances who have built a house, some appeared (including some that tore the wallpaper), and the builder also warned against just plastering the walls because such cracks can occur.

We are only talking about cracks that have no impact on the statics (and according to my acquaintances and the builder are supposedly normal).

Hello,

may I briefly use your thread for my purposes? I would like to start some preparatory interior work in our house, but I am already struggling with the right material.

1. The joints between the filigree ceiling parts need to be closed. What should I use for this? Rotband? The selection overwhelms me a bit.

2. Our walls were plastered with gypsum plaster on Q3. We would like to repair smaller spots here, sand a bit, and then paint. Does a primer or plaster base need to be applied first? Which paint is best to use on gypsum?

Yes, they are normal wherever different materials meet: e.g.: drywall on masonry. Masonry on concrete. Exactly, painter's fleece can cover these small (shrinkage) cracks. Strictly speaking, you should use cement mortar (e.g. R&R mortar) to stay as close as possible to the surrounding material, but we used Rotband and after a year I see no problems on the ceiling, but we also have painter's fleece there. For concrete you need primer, but there are many combination products, just read or ask a specialist advisor. For paint I recommend silicate dispersion paint. It is easier to apply than pure silicate paint but is also highly alkaline and somewhat more vapor permeable than pure dispersion paint.