ᐅ Concrete walls cause rust stains on wallpaper; new construction;

Hello everyone,

we are currently building a semi-detached house. During an inspection, I noticed rust stains appearing on the wallpaper near the concrete columns. I suspect this comes from the tie wire, as the reinforcing steel is not visible. I want to be prepared in case I need to make a complaint. Should the concrete wall have been treated before wallpapering, or is it acceptable in an emergency to simply repaint the wallpaper, hoping that no further rust will appear under normal indoor humidity? Unfortunately, complaints are not always successful with our general contractor.

Thank you very much for your support!

Painting is pointless. They will come back.

Remove the wallpaper, sand down the bumps, apply filler, then put up new wallpaper.

We had rust stains on the corner beads that kept coming through.
A painter recommended an insulating spray to us. We treated the area with it and then painted over it. Nothing comes through anymore.
Unfortunately, I don’t remember the name of the spray.

Hello,

I have already replied about the same issue in another thread.

It is likely caused by the aggregate in the concrete.

Jann St schrieb:

Hi,

I already responded to the same issue in another thread.

It is most likely caused by the aggregate in the concrete.

If at all, rust is more likely to occur only if iron is present. (at most possible with steel fiber reinforced concrete)

I don’t understand why overly formal answers are dismissed when it is clear that there is insufficient knowledge on the subject.

As is well known, aggregate is a natural material. And it should also be known that there are aggregates containing iron. If such an aggregate is present, these kinds of damages can occur.