This isn't exactly a diy question, although it might be in the future. I have discovered that the chimney breast in the loft area of my house is totally saturated with water. There's fungus on the bricks and the mortar can be picked out with bare fingers. At the very least the stack itself in the loft will have to be rebuilt.
Now to the real question. The damage is a consequence of the next door neighbour's chimney not having any flashing (the two chimneys are in one stack) so what can I do? I want to get any repairs paid for by the neighbour, but how do I go about this? Has anyone had a similar situation where the neighbour's lack of maintenance to their house has caused damage to your property? If so can you offer any advice please?