Buying first rental with HELOC

[Bill Bob]

Hello all my name is William and I'm still on the hunt for my first property. I'm about to get my preapproval and hopefully my first property soon thereafter. The question I have is I was planning on using my HELOC for a down payment. I was wondering if just calculating the monthly payback of the HELOC with all other costs/expenses of the home is what everyone does to see if the numbers still work or if they avoid using HELOC at all costs? Thanks in advance!