Short answer
In an older house, you need to understand the source of the moisture before hiding the marks. Materials, the building's age, and usage may point to different causes.
Mistake 1: treating every mark the same way
Saltpeter, mold, a damp band, and water damage do not always come from the same cause. The same building may even combine several causes.
Mistake 2: refinishing too early
Plaster, paint, or wallpaper may deteriorate again if the substrates remain damp or if the cause has not been treated.
Do the marks keep coming back despite cleaning?
That is often a sign that the cause needs analysing, not just the surface.
Mistake 3: forgetting the professionals involved in the case
Notaries, insurers, tradespeople, property managers, or architects may need a clear reading of the issues before a sale, a claim, or works.
Frequently asked questions
Why is the construction period requested?
It helps understand the materials, the type of building, and the possible causes before proposing the next step.