Internal wall archway damp patches

RabidDaisy

Hi we’ve just got round to decorating our downing room after moving in a few months ago. When we’ve painted the dining room archway these damp lines have appeared all the way round the square arch. They are inside and around the edge. It’s an internal wall and above it is a bedroom.

stuart45

Is there a single storey extension the other side of the beam?

FreeBear

Staining from adhesive used to fix the plasterboard in place ?

If that is the case, a coat or two of Zinsser stain block would probably hide the lines.

Grenage

FreeBear said:

Staining from adhesive used to fix the plasterboard in place ?

If that is the case, a coat or two of Zinsser stain block would probably hide the lines.

It looks like it could be something like that.  Stain block or an oil based paint will likely solve it