ᐅ Painting Work for Prefabricated Houses: Which Interior Paint? Paintable Wallpaper?

Hello, we are currently in the middle of building our prefabricated house, and we have some questions about the painting work. The standard in our general contractor’s contract includes everywhere a Q3-level skim coat and white paint using dispersion paint. After the first discussion with the painter, we still have many questions...

Regarding the paint, we want to use one that is as free as possible from harmful substances and emissions, as my wife is very sensitive in this area. As an alternative to dispersion paint, I have read something about silicate paints/silicate dispersion paints, although there are frequent remarks that these are not very suitable for drywall (plasterboard) surfaces. Alternatively, I think certified low-emission dispersion paints could also be an option. The painter informed me that a certified paint (Blue Angel label) would cost €3.20/sqm (approximately $3.40/sqft) more net than the standard, which I find quite expensive.

Furthermore, the painter recommended using painting fleece everywhere, which would cost an additional €8.20/sqm (about $8.75/sqft) net, and of course would be a significant extra expense. Since we have many large south-facing windows, he mentioned that raking light could otherwise cause major issues.

Can anyone provide advice on these points and help reduce our question marks? 😉

So, we had painter’s fleece applied in all rooms except the utility room and painted with washable paint. The painter had to come back a second time because there were slight dents in two spots that caused shadows. These areas were sanded again and new painter’s fleece was applied. After that, it was painted again and now it looks perfect. You usually only notice this afterwards when the specific lighting conditions interact with furniture and fixtures.

The issue was mostly visible in the evening. Since we chose indirect lighting, those two spots stood out significantly.

So yes, I claim that without surface preparation in Q4 quality, visible spots will always appear without using a painting fleece.

You can also apply silicate paint on gypsum, but it won't silicify there. Some people exaggerate this issue to the point of saying "it's not worthwhile." It’s just another advantage that does not come into effect in this case (silicification is a bond with the substrate, meaning the paint adheres not only to the wall surface but is basically "in" the wall). Silicate paint itself is still vapor-permeable and highly alkaline on gypsum, which helps prevent mold.

But yes, the extra cost is considerable. I was charged an extra 2 EUR per m² (2020) for painting fleece, but in the end, I completely dropped the painting service.

In the living areas, we will definitely use paintable fiberglass wall covering. I think for the kids’ rooms and our bedroom, it’s not so important if the walls have some small irregularities.

Regarding the paints again: An important difference between silicate paint and emulsion paint (also called dispersion paint) is their breathability. We have a mechanical ventilation system with heat recovery, so hopefully moisture won’t be a problem. In that case, is breathability still a relevant factor? In terms of emissions, certain certified emulsion paints (E.L.F. plus, Blue Angel, etc.) don’t seem to be any worse than silicate paints.

Well, it’s like sacraments: Catholics have seven, Lutherans have three.

1. Nowadays, dispersion paints are also vapor permeable (at least according to the standard, with an sd value below 0.5m (1.6 ft)).
2. In my opinion, vapor permeability is often overrated.
3. If anything, the entire wall assembly must be vapor permeable—from the interior paint all the way through to the exterior render.

However, (dispersion) silicate paint is still preferable to dispersion paint (in my opinion) because its high alkalinity significantly inhibits mold growth.

On the other hand, millions of buildings have just had dispersion paint applied over dispersion paint on three layers of wallpaper, and there aren’t nearly as many mold cases...

Does silicate paint have any disadvantages besides the price, and what price increase would be reasonable? I find a 3.8€/sqm (about $4/sq ft) surcharge from standard dispersion paint to certified dispersion paint quite steep. Is there any explanation for this other than overcharging? I checked both paints in popular online stores, and the price difference is only about 1.5€/liter (around $1.60 per quart), which on a square meter might only amount to around 50 cents (about 55 cents).