Refinish Old, Dirty Floors Or Do A Serious Cleaning Job?


How do I know if I have to sand my wood floors rather than using cleaners to remove the stains? I am refinshing the floors, and when I removed the carpet I found out that a previous homeowner put linoleum down. There are black mastic stains as well as cat urine stains. Additionally, some areas of carpet padding are stuck to and staining the floors.


Dear Matt

You most likely have to sand the floor after you have removed all the sticky adhesive from them. Most times in the process of cleaning off this glue you will remove most if not all the floor finish. And the cat pee stains will not usually sand out. They will need to be bleached out or repaired.

First try a white non-abrasive nylon scrub pad and a pH neutral cleaner for these spots. Read about these cleaners in the ‘Cleaning’ section of my web site under the ‘Project Categories’. If that fails try odorless mineral spirits, with a white cloth, and then the pad, then naphtha, then lacquer thinner, and lastly xylene in a product called Goof-Off at Again with each try the cloth first and then the pad.

In the worst case you can chemically strip the glue off the floor, and be sure to read about this process in the ‘How To’s’ section of my web site. This will remove all the floor finish from that area, so this may be part of stripping the whole floor.

If all these solvents have no effect you will be forced to sand it off. That may be the least toxic way to go anyway, instead of handling all those solvents. And if the spots will not sand off they can be repaired as told in the ‘How To’s’ section.

If you still have dark stains in the wood, and an odor that goes with it, you can certainly try bleaching with the strongest wood bleach available. Do this after all the floor sanding is done, but before any finish goes on. Try a wood bleach called Klean Strip at It will turn the dark areas an off white color.

The off white colored spots will need a light colored wood stain to blend them in to the rest of the floor. It’s quite an art. You will want the color to blend in with the final finished color of the floor, not the bare wood. Test for the finished color of the wood by splashing some naphtha on the clean wood. You will have to fine sand the spot before staining, but be careful not so sand out the bleached effect. Then complete the finishing of your floors.