So one of The Tell-Tale things to look for is where the down down drain it goes all the way into the basement at connection to the sewer and check those pipes for any type of leakage of rot.

She was quiet and ignored my reminder on rent/ deposit until I served the 2nd 3 day notice on Sunday.She was fuming and claimed the notice was illegal and demanded a discounted rent because the condition is so bad (not clean upon move in, leakage from fridge, kitchen faucet leakage that he had to fix herself blah blah).

We call this (leakage).

We install new roofs on 80% of our properties, and a roof that has enough damage that leakage is a likely issue needs to be replaced.

Anyway, agree that you have to sometimes replace subfloor- and definitely clean the venting system for HVac- and also any cabinets in the basement or anywhere else saturated leakage could go. 

In our area a/c permit now needs a leakage test witnessed by City inspector. 80% of homes built since 1970s here do not pass leakage test.

These will tell you how much you home is leaking and the leakage of your ductwork.

They were decimated and the core MSAs saw minimal leakage and growth at a sooner time. 

Furnace, plumbing leakage?

I think I am going to pass on this one.The next house we looked at was in need of just about everything but structural work....from the looks of it it seemed like an okay investment; then I go into the basement (to be honest with you the place kinda creeped me out; I think it creeped the realtor out too because she didn't walk around with me); in the basement there was water on the floor and it smelled like a serious water leakage problem....I told the realtor right then that I was not interested in this property.