Silicate paint on walls, dispersion paint on ceiling, color differences?

Hello everyone,

we want to start the painting work soon. The walls have gypsum plaster which was subsequently filled. The concrete ceilings will be wallpapered with painter's fleece.

We would have liked to use silicate dispersion paint to paint everything. However, since wallpaper should not be painted with silicate paint because the paint cannot chemically bond with the wallpaper, only dispersion paint is an option for the ceilings. We asked ourselves whether we could possibly order dispersion paint and silicate dispersion paint in the same color from the same manufacturer and paint the ceilings with the dispersion paint and the walls with the silicate paint. Or is it better to paint everything with dispersion paint to avoid color differences?

Silicate dispersion paints can partly also be applied on wallpaper. From a well-known manufacturer starting with S, there is a corresponding paint explicitly advertised for this, which we will probably use for everything.

Why use a silicate paint that is actually not used on gypsum, etc. (and if at all, then with special primers). It is actually intended for mineral substrates. With gypsum, no silicification occurs, and without special primers, it can even damage the gypsum. It offers exactly 0 advantages for that substrate. Please don’t be upset if you are not quite satisfied with the result. Here you have just received a warning.

Why a silicate paint that is actually not used on plaster etc. (and if at all, then with special primers). It is actually intended for mineral substrates. No silicification occurs with plaster, without special primer it can even damage the plaster. It offers exactly 0 advantages on this substrate. Please do not be annoyed if you are not quite satisfied with the result. You have just received a warning here.

Okay, that was not clear to me, I thought since plaster is basically also mineral, the exact opposite would be the case. Then we will probably go for a dispersion paint.

Of course, dispersion silicate paint can be applied. The 5% dispersion ensures that it holds even without silicification. An advantage of no silicification is the high alkalinity and thus lower susceptibility to mold compared to dispersion paints, easier processing, and in my opinion also better results compared to lime paint. So conclusion: you can use a dispersion silicate paint for your walls and ceiling. No magical special primer is needed. I painted my ground floor like this, including both, painter's fleece and gypsum plaster. The paint does not peel off anywhere.

Of course, dispersion silicate paint can be applied there. The 5% dispersion ensures that it holds even without silicification.

Then I might as well forget about the mineral paint. Because without silicification, the alkaline effect fades quite quickly.

I painted my ground floor like this, including both painter’s fleece and gypsum plaster. The paint doesn’t peel off anywhere.

Then look forward to repainting sometime. And remember this thread in a few years ;-)

No magical special primer is necessary.

And please don’t complain if it doesn’t work well, because then you have to ask yourself why you didn’t follow the manufacturer’s instructions. There, the magical special primer is explicitly stated for the dispersion silicate paints. Sto knows why.

Then I might as well skip the mineral paint. Because without silicification, the alkaline effect disappears quite quickly.

How is that supposed to work? Indoors? The silicates then gradually wash out with baby puke and the spit of nagging partners, or what?

Then look forward to when you want to repaint sometime. And remember this thread in a few years ;-)

I will, promised – as long as the forum still exists then.

And please don’t complain if it doesn’t work well, because then you have to accept the question why you didn’t follow the manufacturer’s instructions. The magical special primer is explicitly mentioned there for dispersion silicate paints. Sto knows why.

I won’t complain, or at most to the manufacturer of my paint. Because I followed their instructions.

Just for fun, I looked at Sto. There is nothing about a primer for Sto Sil In in the technical datasheet. It even states “textured wallpaper” as a possible substrate.
For absorbent substrates, primers (nothing magically adhesive) are recommended. Of course by Sto, but chemically that’s nothing special.

So usually, I appreciate you and your posts a lot, but here you are giving credence to fear-mongering craftsmen who want to turn their trade into magical secret knowledge in a medieval guild-style.

Yes, the very durability-increasing effect of silicification is missing with gypsum or wallpaper as a substrate. But you can still paint with a dispersion silicate paint on it because the dispersion as a binder ensures that the paint adheres to the substrate. The silicates are still there and alkalic even before silicification, so the mildew-inhibiting advantage still applies.

By the way, silicification is also a disadvantage if you want to remove the paint later for whatever reason. Then you have to sand thoroughly and several millimeters deep. Granted, you really have to plan for that, because pure silicate paints can be overpainted later with any paint, so there really shouldn’t be a reason to sand off the old paint first. But I just wanted to say it.