Hoping for some quick advice, I have 2 damp patches on a 4th floor gable end wall. House was rerendered 2 years ago but these patches (1 about 3ft below other) won't dry out. I have been advised that the plaster should come off and be redone, but had plasterer around tonight for a quote and he reconed dry linig would work. My worry is the damp would just find its way through, it's not bad, no mould.
Any ideas?