Let's say the buyer notices a leak in the ceiling within few months of buying the property.

Example: I walked a property that had a roof leak that caused extensive damage.

Here's the deal on the table: Off-market listing via a wholesaler, Asking $75K3/1, 1000 sq ft, Section 8 tenant in place on month to month lease (Rent=$650/month which is way under market)Home condition: Nothing I would live in, but no leaks, walls in tact, newer mechanicals/systems (hot water heater, home has a gas furnace) are all in good condition and are fine for a section 8 tenant.

I phoned the last-recorded assignee to see what I could learn, but was told merely that all properties associated with the assignee are with a HUD auction site.  

The risk is that the tank leaks and you'll be looking at crippling cleanup costs.If it were me, I'd make my offer contingent on the tank being removed and the surrounding soil being tested by a licensed environmental testing contractor and coming back clean.

So, I get my inspection and my dad's opinion (I am currently within my due diligence period) and realize that the roof has had leaks and is nearing it's life expectancy. 

The flat roof over an addition had been leaking for an undetermined amount of time.

Otherwise, major liability if someone gets sick, or it leaks and contaminates another property or worse, groundwater.

If you would prefer to forego that expense, there are always 4-mil contractor garbage bags at Big Lots that you can load in a van and empty at the edge of any unlighted strip mall parking lot in the middle of the night.Make sure you don't have a downspout draining right over the area of the leak.

There are certain parts of the joists that are showing some signs of rot, and that could be attributed to a water leak that probably happened in the past.