Silicone resin or dispersion - Which paint for interior?

the question/assumption is less about whether you buy cheaply in terms of price but whether you buy "cheaply" in terms of quality. The price is only an indication of that.

Huh? Why do you drag such statements out of thin air? You should rather address the OP's question than my shopping behavior

Mineral silicate paints, for example those from Keim, make sense in monument preservation. If you want to paint the interior of a wall from, say, 1450, you have to consider that in 1450 one could not build airtight. Moisture will always penetrate the wall from outside. If you now apply normal cement plaster plus dispersion on the inside, you will quickly get bubbles and then widespread plaster peeling. Therefore, one plaster on the inside with lime mortar, which is breathable, and paint with silicate without dispersion (!), caution, colors like StoSil or similar do not work, here acrylic dispersion is the binder, they are not much better than, say, normal dispersion stoBasic with titanium dioxide instead of minerals as pigment. The real silicate paints are two-component products, you get a bucket with a water-based binder plus a sack of minerals and must mix both by hand or with a stirring device, then apply quickly. The result on our 1450 example wall will be a surface that lets external moisture pass through and releases it into the room. Of course, these old rooms are never really dry, and when cold, everything inside is clammy, but that is simply state of the art in 1450. Do you want that in your apartment? No. That is why you take gypsum or lime-cement plaster, hard clinker and cement mortar or Ytong adhesive, then you can also use normal interior dispersion. With eco bio etc., they can also take money from your pocket. If you buy good interior dispersion, i.e., painter quality from Maleco, Sto, Caparol or Brillux or similar, then one coat is enough and you can also do some patching without it showing up later. K.

your wardrobe and your solid wood dining table store and release more moisture than all your walls... Man, it never stops. if you want your wall to breathe, you have to keep the window slightly open. if everything in your house is made of V2A except the wall, then I would also make it diffusion-open. but since even the opened pack of rice in the kitchen cabinet "breathes," you can really save yourself the effort...

How do you come up with such nonsense? The wall surface area in your house is huge, the plaster about 2 cm thick. It can store and release thousands of liters of water. Silicate grants you this positive breathing effect; dispersion is plastic and strongly inhibits this effect. But you can live with both, silicate is a luxury. Dispersion is cheap and sufficient. Controlled residential ventilation takes over moisture regulation. Silicate also has advantages for allergy sufferers. I think that's good.

"That escalated quickly."

My original question was rather which type is best suited for the interior. Since the painter brings the paint (and we only contacted known painting companies), I absolutely do not assume that they would use these cheap paints.

Otherwise, I’m a bit wiser now and summarize:

We have normal masonry, no timber construction etc., and ventilation is conventional through windows. Silicate would be the best choice. If dispersion is on it, which I assume, then it’s best to also put dispersion on top, it breathes a bit less, but due to the wall and previous coating it’s not really decisive anymore (paint that breathes better on top wouldn’t help either). Silicone resin for outside, I just don’t understand why it was offered so often, it made me a bit suspicious.

Then we also make sure that licking the walls won’t cause a toxic attack (stiftungfarbe.org) and it should be fine.

Addendum: I wrote before the last post. What do you mean by advantages for allergy sufferers?

With us, we have completely Keim Biosil on the walls and ceilings; it contains about 2% acrylic and not 20% or 30% like with dispersion paints. Due to the pH value, it acts germicidal and mold-repellent. Completely without solvents and without allergy potential. And it does not need biocides. Others get upset about microplastics and buy everything organic. But then they smear their ceilings and walls (in which they spend 14 hours a day or more) over several hundred square meters with biocides and plastic. Maybe one could think about that. Nobody else cares anyway.

Anyone who seriously believes that, attention quote "can store thousands of liters of water," really cannot be helped anymore, sorry. You are here in the range of 70-90g/24h storage capacity per m² of lime-cement interior plaster; with gypsum plasters, you don’t even reach half of that. That then works for a maximum of a few days without the moisture being released again, but by then you would already be living in a dripstone cave.

Just because the plaster once consisted of thousands of liters of water does not mean that it can absorb that again.