Hi went to look at a job today in a big old house today,rooms were lined and papered 15 years ago.The wallpaper is stained in places I presumed it was moisture coming from the old lime plaster behind,the strange thing is they have the same staining on a partition wall that was papered at the same time,they want to avoid stripping the paper as a lot of the plaster had to be patched the last time,I know its not ideal so I am looking for opinions on whether a sealer maybe zinsser wallpaper...
Old wallpaper stains
Old wallpaper stains