Hi the people who live upstairs loo pipe is leaking into are place wall and floor falling apart the pipe is in a wall as it is massonette is it easy to fix and is it my place to fix or them

More details please! Is this a condo? Do you have a Condo board? If the leak originates in the upstairs unit then the repair's on them but if the leak is a pipe in a wall that shares drainage then it's in a common area and the Condo Association picks up the tab. Good luck and let me know how you make out, Tom