Isolate the issue or open up completely?

[Allana Alex]

Hello BP members, 

In the process of purchasing a house hack. Property has been neglected and I have concerns about plumbing as house is 70 years old and it was neglected by previous owner who simply did patchwork repairs while never addressing the problems.  There is a a leaky faucet in third floor bathroom which has created damage to second floor's bathroom ceiling in addition to some other possible pipe/water issue as it was mentioned that after taking a shower water was found directly outside of the bathroom on the floor of the third floor apartment .  Should I gut the entire third floor bathroom and see what's behind the walls and completely renovate while at it? Or  should I attempt to isolate the problem if it can be resolved with removing just a few wall tiles?

The bathroom tiles wall and floor are in good shape and clean.  They are however the 1970's coral pink along with the bathtub and sink to match .  Just wondering if I should start fresh with ownership of this house and know everything that's behind the walls or save money and keep whats there there if i can isolate the issue.  Property is in B neighborhood but its possible that I may end up with C  tenant with program.