Cash flow is what is left after every one of those costs is paid, and it can be positive or negative on the identical house depending entirely on the buyer's down payment and interest rate. A buyer who puts down CMHC's insured minimum of 5 percent carries a larger mortgage payment than one who puts down 20 percent, and that difference alone can turn the same rent into a positive or a negative number.
Vacancy and maintenance are the two costs new landlords underestimate most. A month without a tenant between leases, or an unexpected repair, does not show up in a rough back-of-envelope estimate but shows up immediately in an actual bank statement, so a realistic analysis reserves for both rather than assuming a property rents every single month at full price with no repairs.
Run the actual numbers for the specific Erindale property you are looking at before you commit, because a rule of thumb about the neighbourhood will not tell you what your bank statement will show. Get your hand-reviewed valuation from Joel Dyck.