@Ron Flatt it’s moisture vapor, it’s constantly passing through an uncovered slab.

Technically a tenant can be help responsible for not informing a landlord of water intrusion, but in this case you did have your inspection period during which you had the opportunity to uncover any issues, so that would have been the time to conduct your due diligence, and it sounds like they did let you know about the issue at that time.

I want to be fair and don't want to take advantage of him but I don't think it's fair that I incur the expense of newly uncovered repairs.

These strategies can help you uncover off-market deals that might meet your cash flow criteria.Remember, patience is key when searching for the right investment property.

Whenever you take on a renovation project you never truly know what you’ll uncover until you get in and start doing the work.

That uncovered a million dollar lien.  

Also as "hot" markets become overheated, how important it was to examine the data to uncover the next "hidden gem" markets-Platform Risk - A lot of talk about setting up booking direct and how to market that to reduce your exposure to AirBNB and to a lesser extent VRBO. 

This method (for me) hasn't uncovered "desperate to sell apartment owners" but I have made a few informal "standing offers" on buildings.  

I'd go to these sellers, uncover those that are motivated, and try to buy for 10-20% under the asking price.Prices are already down 20% from the peak in some areas.

Say 150 uncovered surface spots.