Should I renew tenants lease in duplex so I can value add to refi

[Paul Tibok]

Hello BP, new investor here.  I bought a duplex Florida in August. I live on one side and rent the other out to inherited tenants.  Currently their rent is under market (by about $225) and the lease is up the end of January.   The tenants have expressed to me they would like to stay but I am debating not renewing with them because their unit is completely carpet and I would like to change it to all tile like my side as well as do some other renovations to add value so I can refinance, get some cash and buy another rental.  Is this enough time for a bank to let me refinance?  About how much value will I add from switching to tile floors?  Does anyone have any other suggestions on how I can increase the value of the property?  Should I wait another year to do this? Will increasing the rent also be favorable to me when I go to refi? .  Please excuse the title not making sense I ran out of space haha. Any help would be greatly appreciated