Timber frame construction - Diamond gypsum board - Painter's fleece

Hello everyone,

a question for the experts.

Our house is built in timber frame construction and all walls and ceilings are covered with Knauf Diamant plasterboard.

Now the question about the pretreatment for gluing painter's fleece, which is then to be painted white afterwards.

Painters we have talked to want to do Q4 filling, for a corresponding amount of money in total.

But I myself think, the boards are already very smooth, fill joints and screw holes, both twice, then sand smooth, then apply primer all over and then glue the fleece.

I don't know why, but I have the feeling Q4 doesn't really have to be applied all over on smooth gypsum boards, right? Actually, almost Q3 would already be a bit overkill. This is not an old building with crooked old plaster and chipped corners and holes. But a new building with flat and smooth gypsum boards on the inside.

There is painter's fleece and "painter's fleece". There is painter's fleece with 50g/m², which rather emphasizes unevenness. We took thick one with 130g/m² that covers everything. You really only need to fill the joints. I would skip Q3/4 on drywall panels if [Malervlies] is going to be applied anyway. But then take a heavy one.

Yes, I had/have similar thoughts. The tip about the heavy fleece is noted. Strange that they all think they have to do Q4.