How do you pay for items on a rental if no rental segregated savings yet?

[Brad H.]

Let's say I'm looking to start renting primary residence in April. Driveway needs redone. Renters move in. Rent covers mortgage + $1000/month. Driveway cost $6k. I wouldnt have enough in my rental designated bank account to cover driveway project until 6 months from start of renting. How do you pay for things like this earlier than waiting for cash flow accumulation in a way that is most advantageous for tax/write off items?

Also - let's say the tenant doesn't pay rent in time prior to when mortgage is due and you dont have enough in the rental designated bank account, how would you cover? Everything I read says not to co-mingle personal funds with it, but you cant wait until rent hits...

Thanks!