Newbie: Gut & Replace Floor Joists/Subfloor?

[Austin Hefner]

Hello All,

Background: I am new to RE investing, and i am closing on my first duplex in 2 weeks. I will be living in one half of it and renting out the other. I have little to know experience with home renovations, but i'm pretty handy otherwise, and I'm an engineer that likes to figure stuff out. I am single and have plenty of free time, but not plenty of money.

Situation: My half of the property has floor joists that are 24" on center, thus the floor is quite bouncy. Because of this, there are substantial high/low spots in the floor which is currently carpeted. i cannot put down click floor or even subfloor/vinyl without waves and cracking and just issues in general - so I'm told. 

Idea: My contractor friend said that I could just rip up the floor, leave the current joists as they lie, insert new joists 16" on center, and put down plywood subfloor. There is small elevation change from the door to the next room, but i could account for this gradually with the joists and it wouldn't be noticeable. I feel confident in my ability, and materials don't seem to be that expensive. Living room is 10' x 17' and should have NO major plumbing/electric running through the floor.

Thought Process: My vision for this unit is to take out the wall between the kitchen and living room, put in vinyl flooring, and revamp the bathroom. Once done, my value-add would likely be 150-175/mo.

Does anyone have insight on a project like this? Thanks in advance for any help.

[Parker Eberhard]

@Austin Hefner if the subfloor is in good shape and you have access to the joists below, I would just install joists between the existing ones, giving you joists 12”oc. Use a good subfloor adhesive and screws. The other option is to add a second layer of 3/4” t&g cdx ply on top of the subfloor if you have the ability to maintain critical heights with your subfloor (you can always undercut doors and use transition strips if needed). Once again use a good subfloor adhesive and screws to do this. If you want to level the floor and are putting the second layer of plywood down, you can use the subfloor adhesive as a ‘liquid shim’ by letting the adhesive dry between the existing and new subfloor before screwing things tight