Question about the BRRRR strategy

[Glenn Mayo]

Ok, I REALLY like the BRRRR strategy. In fact, once I get going, I think it's going to be my primary strategy. But I have a question about the refinance part of it. What are the conditions to refinance? In other words, let's say I get into a great place, go through all the rehab and rent business, but when I go to refinance, I get denied? WHY would a bank deny my refi, and what will cause a bank to approve a cash-out refi? That's the stickler for me, because I don't want to lose a great, cash flowing property because I can't get a refi. And I'll likely need one, because, at some point, I'm going to have to use hard money.

Speaking of which, another question: are hard money loans generally interest only for the duration of the loan?