Extractor fan in chimney breast

[Strawberrylemincake]

I’ve just moved in to a 200 year old cottage. I’ve had to increase the size of the space in the chimney breast to fit my range. The wall was wet and the board easily came off. I’m wondering if there might be a problem with the chimney and moisture. I had a survey and he said I need vents and a cowl which I’ve organised a builder for. Anyone have ideas? I’m about to replace the extractor and wonder if it’s something to do with the chimney.

If it was uncapped and had no ventilation then the chimney is acting as a deep bucket. They have to have ventilation or you get these damp issues. Once the builder has done the work it will take months to completely dry so I wouldn’t do too much extra work in the area for a while