I prefer not to do roofs anymore but its not out of the question.I have been putting together a team lately consisting of an agent who works with sales and rentals, a broker and an accountant who invests in property himself and has been a personal friend for years. 

This would be a fully rehabbed property, so I am expecting CapEx would be low, but I want to make sure I save up enough during say the initial 5 years so I don't lose money when say a roof needs to be replaced.  

a roof is a roof regardless if rent is $450 a month or $800 a month. 

A chunk of the kitchen ceiling has fallen down but the roof appears to be in good condition.  

Issue are: roof, windows and bricks.Thanks

That price seems steep but depends on how nice the property, age built, etc.

For example, a roof has an average life of 20 years so each year you should put 1/20th of the cost of a new roof in reserves.

That could mean anything from unsafe steps, non functioning or inadequate heating, leaking roof, to a biological hazard such as human or animal waste. 

I would think about the cost of a roof, various plumbing expenses, electric work along with 6 months of PITI.

The roof will need about $18,000 of repairs (rough estimate) in the near future because of deferred maintenance by the current owner.