Cash out refinance on primary

[Joe Attard]

I am weighing the benefits between a cash out refi on my primary and a conventional loan.

I understand there is more risk attaching my primary to my investments.  However, I would benefit from the refi rate on both assets. 

If I pull 100k cash out and invest in my rental, how do the taxes work?  Does the principle and interest deduction get split between my primary and  rental property? 

Thanks, Joe