In redoing a wood floor, preparation is the key to a to a good looking floor. I have run across some wood floors that have been previously treated incorrectly & thus creating problems for the next person to treat the floors as well as lessening the life expectancy. I have seen floors treated with a chemical stripper & then the residue is left in the wood. When you try to refinish the wood, the new poly will not adhere as the base coat is still being chemically attacked. Then there is the mop the stuff on your floor & restore it to its natural beauty without refinishing the floor products they sell the public on. The bottom line is that wood floors are a very basic maintenance & procedural floor to take care of. If maintained properly with a real wood cleaner, a real poly type sealer & kept clean, they should last you many years in your application. Remember wood floors are an expensive initial cost to install, but can pay for themselves over the 25-40 years of service they will give if correctly taken care of.