This diagonal crack is above an internal door and goes into the ceiling
It's an old house that's been converted into 2 flats, we're the top flat there is an attic above
I'm told it's lath and plaster however even the landlord has no idea what it is and he isn't interested in fixing the crack at all!
I've read that cracks above doors can be down to structual problems or a roof issue
I'm truly terrified and have no idea how concerned I should be :/