We bought a 1800 cottage last year and are on a steep learning curve looking after a period property so all advice gratefully received. Our cottage is mid terrace and this is a party wall. It has not been painted in breathable paint and we believe the plaster is modern - it certainly is in an adjourning stair cupboard. We naively repainted the wall using the paint that the last owners left but the lighter colour remains. The area which is lighter appears to have been replaced and filled badly. We don't have any information on why. We are not sure if the paint is reacting to this filler or there is potential damp. There is no obvious damp to us e.g. smell/mould/cold and no obvious issues on the neighbours side of the wall but we are newbies at this. We are considering whether to have the filler removed and replaced with lime plaster or would it be better to test for damp first? We are picking up from reading that it's all too easy to get sold damp treatments when breathability is key. We are reluctant to take off the plaster on the whole wall if we can avoid it so if we just repair this area with lime plaster and breathable paint should that be OK? Thanks for any advice/suggestions.
