Liquids

• Any liquid has the potential to break down the finish and cause a stain if allowed to remain on wood floors. Water, alcohol and perfume spills are notorious for leaving white spots or marks on wood floors. Large puddles of water can also cause the wood to warp or crack, resulting in permanent damage. To remove white marks, rub the spot with ammonia or a cleaning-polishing wax. Rub matte finishes with a fine piece of steel wool, but do not use steel wool on high-shine finishes.
  
  

Dyes

• Permanent markers, dyes and even berries, or other pigmented foods can stain through a wood floor's finish. To remove marker or dye stains, wipe the area quickly with a bit of nail polish remover. The polish remover may remove a bit of the finish, as well, requiring a touch-up. Treat berry stains with a creamy cleanser.
  
  

Sunlight

• Over time, sunlight stains or fades wood floors, lightening the appearance of the entire floor or small areas where intense sunlight shines. Protect your floors by installing draperies, blinds or UV window coatings. Area rugs can also protect floors from sun damage.
  
  

Pet Stains

• Alkaline substances, such as pet stains and urine, wear through the finish if allowed to remain, and over time, may leave a dark stain on a prefinished hardwood floor. Of course, the best solution is to wipe up stains promptly, but occasionally, a homeowner may not be aware of a stain until the damage is done. Try cleaning the stain with vinegar or a surface cleaner labeled for hardwood floors. If the stain remains, though, sand and refinish the area.