Damp in basement - concern for renter's on second floor

[Ruth Buckley]

Hi BP, new to rental property investment. We have had an offer accepted on a 2nd floor condo we plan to rent. There are 3 condo's in the unit, the other two units are also under contract at the moment. The deal would be cashflow positive which is not easy to find in this area. 

On inspection, evidence of high moisture was noted in the basement. The inspector recommended further investigation. The Seller's proposed solution (add a humidifier) does not solve the issue. The seller has been accommodating on other items (eg. closing off a doorway to create a 3rd bedroom).

We have asked if we can have a professional company assess the cost of repair so we know what we're getting in to. Is it likely that the seller would allow us to contact the other two buyers to discuss sharing this cost with them after the sale has gone through?

Also, if we did not fix the root cause issue will it really impact tenants on the second floor? In the long term it would make sense to fix it properly. 

Any thoughts or experience with similar scenarios?