Payback Period on Small Renovation in C/C- Neighborhood?

[Luke Soroka]

I just purchased my first property (duplex) in a C/C- neighborhood.  Both sides are rented with long term month to month tenants.  Both sides need pretty minor fix ups which will be completed by a contractor.  I also have quotes to update the kitchen on one side and the kitchen and bathroom floor on the other side.  If those are done, I plan to increase rent.  My question is, what should be the expected payback period on those upgrades?  The tenants are not paying a lot in rent and I want to try to strike the balance between making my money back in a reasonable timeframe and not increasing rent to the point where they can't pay.