That was not the intention.Let's just say that all of the Universities that have financial degrees, other professional degrees such as CCIM, CFAs, etc. all need to understand these calculations.It's a requirement for these degrees and designations.What I am saying is that learning the IRR is really NOT hard at all, whether or not you believe it will help you, the evidence does point to the ability to have this particular calculation as one of the best tools in your financial tool box.The problem here is that if those of us who really understand the calculation of IRR can clearly show that Positive, Negative, Neutral cash flows, Zero, Negative or Positive Appreciation, etc. can all be taken into account with one calculation and regardless, it can be proven mathematically that there are enough scenarios to dispute the theory that only Positive Cash Flow Properties are the safest and highest returns for an Investment.I'm hoping that there are at least a few people reading this thread will want to investigate it, but having people say that HEY...

Remember, you can take over the leases and tenants can later claim they had verbal agreements with the seller and you would have no evidence to the contrary. 

The take away is that we know based on evidence that real estate can lose value, so there's nothing wrong with being a little cautious if conditions warrant it.

The level of knowledge exchange is low and this post is the evidence of the poor mentality of many people who do not appreciate educationGetting the right mentor who is a practitioner and has a structure you can join is the teal game changer.In closing, in case I was not clear on why that mentor who is a multimillionaire many times over does these handful of seminars in California each year and upsells his $30,000 four day intensive event, well it is to groom his students to do the joint venture agreements with him on commercial deals, to drop their taxes and use the tax savings and to become Co-sponsors in his real estate funds and compound everyone’s returns including his.

Ask for all the evidence of the repair--What structural damage, if any, was repaired? 

At that point the evidence will be had.

All you have to do is look at the market for evidence of what makes sense and what doesn't.

There is enough evidence that the leakages existed before the transaction, and the seller temporarily covered them for sale.

If you have evidence he royally screwed up, he should return that deposit too.

You want to keep evidence of this for your tort suit down the road :D.