We purchased a probate sale house and have later found that the chimneys on our roof are not all ours. The neighbour informs us that one stack serves the adjoining property however it is on our roof. Our property is a story higher than next door. They are pushing for a party wall agreement as our chimney stack needs fixing, as does render on our wall which extends above their property (rendering that section our wall and not a party wall). They are trying to stop us fixing our render and also refusing to allow scaffold above their house (not on their property but in the air above)
has anyone been in this sort of situation before?