Who s to blame for a leaky bathroom?

I was also a victim in sympathy for the landlord...

It is best to ask for help from the property management and community neighborhood committees first, this is my suggestion, you can see the situation! People value harmony!! If the neighbor is still unwilling, then you can try to solve it through legal means.

Require the other party to eliminate the infringement and compensate for the relevant losses. However, the court may require you to provide relevant evidence, then you may have to ask the relevant authority (such as the department that provides engineering quality appraisal) to conduct relevant appraisal first, to prove that the water leakage in your house is caused by the upstairs residents, and it is caused by improper renovation and construction upstairs, and you can directly sue the current residents.

The above aspects can give you reference, if the landlord still has questions, you can go to the community of lovers to see, you will have a certain help.

Maybe the water pipes are aging! That's a big problem.

Sue them, put the property and the owner of the upstairs together, and let the court determine who should be responsible.

In this case, you can coordinate with the neighborhood committee of the community, if it is really not easy to use, you can consult the relevant laws and regulations, and the law will give you justice.