Hello,
In connection with the renovation, our builder discovered mold behind our wallpaper. We bought the house 3 years ago and the house was built in the early 60s. The room is located on the upper floor against the short side of the house which has a concrete wall. The long side is a wooden facade. The mold is along the wallpaper. We have not noticed any smell or had any suspicion of moisture/mold before.
How should I proceed now? Is it something covered by insurance? Is the seller responsible for it?