I like to calculate all cost I have into property and if my cash flow will not replenish my funds into property in 5 years or less then it is a no go for myself. 

You just have cash-flow to replenish the coffers quicker. 

For me I am just a year ahead on my materials and they will need to be replenished anyways.

We will gradually replenish our savings with income from renters but not nearly as quickly as we could with a Fix and Flip.

The extra months on top of the 12 months up front is for "cushion" because you are not going to make your mortgage payment typically until the 2nd month after closing, so your escrow account will not be replenished for those two months you are not making a payment.

If they did damage and you deducted from the deposit you need to replenish that now.

If many items need to be replaced sooner rather than later then I would plan on having a reserve fund already in place to replace those quickly and then the monthly reserves can replenish the maintenance fund. 

Maybe change the meaning of the fourth "R" to "Replenish" since you are getting your money ready for your next acquisition.

It really depends on how much equity you have in your primary residence.You could also use the HELOC for down payment and cash reserves for any rehab or maintenance needed.Then once the property is stable you can cash out refinance to pay your HELOC back and replenish reserves.With the limited information provided this would be my suggestion.

Or, if you have the money to get the loan, then get a second mortgage to replenish your cash or give you more working capital, that might work, too.And of course, you should speak with actual lenders.