Rust stains, water stains, roller shutter - next steps

Hello everyone,
we are currently building with a contractor and I want to ask about your experiences with the following problems:

1) Several seem to be struggling with rust stains in the ceiling. In our case, they are scattered sporadically over the precast concrete slabs, always circular (not elongated) with a diameter of up to 2 cm and very dark rust-colored. Suspending the ceiling with plasterboard is not an option, as we need the room height on both floors. The painter wants to paint everything with isolating paint and not sand anything down; apparently, the rust comes from the rods in the concrete ceiling. Do you think the rust stains will be permanently sealed this way? Are there better alternatives to cover these rust stains?

2) After the screed was applied, the house was briefly so damp that permanent water stains formed on the plaster. The painter also wants to cover these with isolating paint. I don't really like this idea, since it is a new building, and I don't want to just seal my walls right away, and above all, not have to deal with the contractor's mistake that the screed was heated incorrectly. Are there alternative ideas for this as well?

3) The roller shutters are installed, and it becomes apparent that the preparation was not done well. On the one hand, all the shutter tapes run very crookedly, not parallel to the window but moving away from the window downwards. So the upper outlet and the box for the roller shutter tape are not aligned. On the other hand, the upper outlet is so deep inside the plaster that the tape lies on the plaster. Is the only option here to break open the masonry and reposition the box for the roller shutter tape? I am a bit desperate.

Many thanks in advance for your advice.

I would promptly call in an expert for this.

Rust is one of the most durable and abundant pigments there is. A test spot would help, although it is not certain whether it will not still come through in two years. But often it breaks through as soon as the moisture of the next layer is applied.

Dampness should dry out, possibly also with construction dryers, and not be trapped. A moisture measurement can provide clarity here. Leak detectors have good devices, the screed installer also has some. But there are also devices that cost in the double-digit range for home use. If you want to cover the screed, you will have to measure the residual moisture beforehand anyway, maybe you can combine that. Unfortunately, your post does not say how old it is or what it looks like.

If the roller shutters or the straps are in such bad condition, one should consider a change before the painter has done his work on top. For me, this would certainly be a complaint and a case for an expert. It can also be a specialist or an architect.

If it looks like this, you often have the choice between spending more time or doing it well. You should make this decision for yourself and act accordingly. Once something has been built over or on top, correcting it can become disproportionately difficult and then your chances are bad. In principle, complaints should be well documented with photos, reported by friendly but clear registered mail, and rework demanded.

I wish you calmness in dealing with this; it will not be the only one.

Good luck Gabriele

The rust stains on the ceiling are quite normal. [Sperrgrund] is applied as a primer and that's that.

Rust stains on the filigree ceiling are very common and manufacturing-related. This is due to the rusting reinforcement steel in the ceiling. As a rule, sanding is usually sufficient here. I had many construction sites where the stains disappeared after wallpapering. The ceiling is then dry and does not continue to rust. A primer is also not bad. Only with "exposed concrete" are further steps necessary.
That the house resembles a dripstone cave after the screed installation is completely normal. Start with shock ventilation (not constant draft!) after one week and the ordeal will be over in 14 days. The walls also dry quickly. Please do not paint anything there.
You must complain about the installation of the roller shutter box and/or the plaster and demand proper installation from the companies involved. As described, it is botched.

1. Let the painter handle it, he knows what he's doing. 2. Here too, let the painter handle it. But have him use normal paint. The moisture from the screed is completely normal and will dry out. 3. Demand correction. Crooked beams, etc. are by no means state of the art and are simply incorrectly installed components. It may also be easier (cheaper) to switch directly to electric drives rather than having to break everything open again now and bring it into plumb.

...Sorry, that messed me up...either more construction time or be satisfied with the worse...