I have wood floors in my apartment. Parts of the floor have water damage and are stained very dark. Can they be refinished?
Please read my article about hiring floor contractors available in the search box at the top of this web page. Find a good honest floor mechanic that will take a look at your job. I really cannot really tell from here.
But here are a few clues. Water stains are gray or black in color, and will generally sand out on the first pass of sandpaper. You can test for this initially with a long handled floor scraper (about 5 bucks) at http://www.richardtools.com, choose the W series. Sharpen this type of scraper with a 10″ mill bastard file and scrape down to the bare wood. If the stains come out right away, it will certainly sand out also. But if it merely fades a bit, keep scrapping. If it proves too deep you may have to replace this board. Smell the wood at this point, and if you smell urine or feces, as this maybe was the cause. You can bleach out some of these organic stains, but you will need to see how extensive the really bad ones are.
You can also darkly stain the whole floor. The stains will still be there, but a bit less noticeable. You will need to have the whole floor professionally sanded (don’t do this yourself), then bleach the stains, then consider dark staining the whole floor. Then you can finish the floor yourself, that’s the fun part anyway.