Of course, upgrading to higher end materials/shingles will throw that component out of balance. 

I thought I could offer $85K and depending on the inspection see if there would be anything unexpected that may eat away my rehab budget. 

A lot of people add fear is a huge component onto why you’ll hurt to lose some money.

But didn't expected to find all other important components near the end of their life as well.

The lender gives me a loan for conventional mortage with 20% down on primary residence (lower rate than when buying investment property) But something unexpected happens after closing date and I can't live in it.

Consumer, this was totally unexpected, no way we could have foreseen this, totally a surprise, but let's talk about a 30YF"), surcharge them a bit on the 30YF (what they do qualify for), to subsidize the very small minority actually getting the 15YF.

I feel that this component is a liability to have in a fridge IN a rental (single family in an intact, transitional neighbourhood).

There are two components to successfully BRRR successfully.

From conversations with previous tenants, the landlord is currently serving a prison sentence having inherited the properties unexpectedly. 

My bigger concern is whether she can actually afford the rent long-term, or if any "unexpected" event from here on out will put her further behind.