Paint Coming Off Walls

[Boto]

I am redecorating a spare bedroom. Before I bought the property the room was just painted. It is now papered. I have stripped some of the old paper off but on the outside wall some of the old paint has come off as well. I assume this problem is to do with damp. The plaster looks quite good still. There is cavity wall insulation. I must admit I do dry clothes on the radiator as we don't use this room much. After this long intro my question is - is there anything that I should perhaps paint (? No more damp? or similar)on the walls before repapering? Or anything I should do to make sure the new paper is ok? Thanks a lot.

[The Builder]

I guess decorators would suggest just "sizing" the wall first.

http://www.wickes.co.uk/wallpapering-size-45l/invt/610089/

An alternative would be a dilute coat of PVA to consolidate the flaky bits (5 of water to one of PVA)

[heathfield]

Depending on the type of paint used on the plaster, it's not impossible that the paint itself could have been penetrated by moisture from the wallpaper paste. Then, when the paint dries out again, it could become detached in places from the plaster. This would be hidden by the wallpaper. I'd go with Builder's suggestion regarding PVA, after giving the wall a light scraping all over to get rid of any remaining loose paint.

[theshedman]

Another cause may be that the original paint was put on without first applying a sealing or mist coat to the wall so that the paint didn't adhere properly. This can quite often lead to this type of thing happening. Before papering apply a thin coat or two of size to seal it then paper following the instructions.