Our kitchen floor facelift, Well according to Google Tongue flooring came out around 1885, This was close to 100 years after this kitchen floor was put down! Needless to say no subfloor below allows air to seep through between the boards which are roughly 3/4″ thick nailed to the floor joists. It really is the worse floor in the house and the most used.
Ideally I would have liked to remove them and put down sheets of plywood and reattached them on top then sand and refinish them, big problem because the y run below the walls. seems they ran the floor boards first then built inside walls where the needed, leaving no support at some of the baseboard.
Well my easy way out for the kitchen was to secure the boards with good deck screws and attach a water/vapor underlayment and install a water resistant flooring this after all is a kitchen and not really real wood friendly.
I also came across an unused dryer vent hole in the corner with sandpaper and thin press board tacked in 2 spots, it warped and doing nothing to keep drafts out, I could only shake my head.
You will need to open each picture to see a larger size.