
Quoting
Mr. Knowitall
If the landlord fixes leaks once they are reported, that's usually sufficient to satisfy the landlord's duty.
If the leaks are not being fixed properly, then that may be an issue.
If the leaks are from the upstairs neighbor overflowing a sink, toilet or shower, that's not something the landlord can prevent, nor is it something that the landlord can address until the problem is brought to the landlord's attention.
If you want to discuss the landlord's potential liability for any given leak, you will need to tell us about the specific leak and why it occurred.