Hi all. I paid a decorater to wallpaper my sons room, he done a amazing job and he's coming back tomorrow to try fix it but I just can't get my head round to why this happened? It's literally fallen off the wall, he told me to take it all down and lay it flat on floor which I did, he's been very nice and said he will sort it, does anyone know why it has happened ? Will upload photo of what it was like then 3 hours later what I walked upstairs to see it like? Thanks all.