You need to find out what they found as the source of the leak.

I've heard of people having small issues like a leak.

Otherwise you have water and sewer leaking under the foundation which will probably cause you another issue in the future.Now with all that being said, you're looking in Irving. 

(3) Water - Typically paid by the landlord, but pay attention to any leaks or inefficient fixtures (i.e. old shower heads, toilets, etc.) (4) Insurance - The world of insurance is vast.

Learn how to inspect a MHP, run some cameras down the sewer lines, check for water leaks, other infrastructure, etc.

Also, verify that all of the units are rentable.....be sure that none aren't being rented due to roof leaks, etc. how old are the building and what type of material are they made of?

Things like the age of the house, condition of the components of the house, class/quality of the tenants and how hard they are on the property, how long existing repairs are allowed to go unrepaired (e.g. if a roof leak were to not be repaired in a timely manner it could end up causing additional ceiling, wall, and/or flooring damage that maybe didn't have to happen), etc. 

If it has a basement, ask does it leak? 

What repairs are covered by the bill ...heat, electricity, natural gas, leaking roofs, broken windows, etc etc? 

I have a leak in my roof that needed to be repaired.Thanks!