Can anyone tell me if this is damp? There is yellowing on the wall around a window (see attachment). I've had 3 damp proofers look at it, 1 said it is damp and that he'll need to replace the beading and re plaster at a cost of £290 + VAT, the other 2 said it's not damp (one said it was too high up the wall) and that it is rusted beading and not to worry about it.
Can someone please help
Cheers
Peter