I'm considering putting an offer in on a house that is a fixer upper. I'd like to keep the original (1945) hardwood floors but am concerned about their condition.
The floor has a large bare spot in the middle of the room where it looks like the stain and varnish have been worn away leaving the bare wood exposed. Other parts of the room have large black spots (2-3 feet long).
My goal is to sand the floors so they are no longer a darker wood color and then re-stain them a light maple or a natural tone like sand.
Solid hardwood floors can be refinished several times. However, we don't know enough about your floor to answer properly. Some factors:
How many times it's been done before. Eventually you start getting through to the tongue of the plank, which leaves thin spots and gaps. You might also start seeing nail heads.
How severe the dark spot damage is. That might be water stains, which can go quite deep. If they're deep and dark enough you won't get them out entirely.
The color you plan on using. The dark stain that's on there now may have seeped all the way down the vertical faces of the planks. That, along with the water stains, may mean you won't get a nice finish with a light stain or just varnish. You may have to stick to a darker color to mask those things.