I'm about to buy a converted flat in a large two story Gerogian house. My flat is on the top floor, but I have noticed that the floor beneath has large horizontal cracks, going across the the top of both of it's bay windows. Now, I appreciate that cracks and old properties go hand in hand but I remember reading somewhere that it's the horizontal cracks that you need to worry about, I'm also concerned because they are external... So I'm wondering is this something I should be worried about and if it is, what could it indicate and what would need to be done to resolve it?