All the time I meet different people for an estimate who assume that their old Fir floors cannot be refinished, so they think that they will install new flooring over the floors. Usually the floors have been covered in paint, carpet, or linoleum forever and as time has gone on people have realized the best looking of their options is a wood floor. One important thing to understand about the floor sanding process is that usually only 1/32″ to 1/16″ of flooring actually is removed during sanding. If you consider that a wear layer on a floor is typically 5/16″ and a quality refinish will endure 10-20 years of wear with proper maintenance, then you can see that most floors ,even those that are 100 years old or greater, have some remaining life. I have seen some of the worst hardwood floors be revived in 5 days to a state of beauty that few would expect. My answer is almost always, “Yes, you can sand that old Fir floor!”. It’s more cost effective and has less impact on the environment because you reuse an existing resource.