The primary factor for refinishing is the remaining thickness of the wood's wear layer. For solid hardwood, this is the amount of wood above the tongue and groove connection; once the floor has been sanded down near this join, it can no longer be refinished. Professionals perform a test in a hidden area to check the thickness. Furthermore, the overall condition of the wood must be evaluated—if the floor has been subject to extreme moisture or extensive pet-related damage, the wood fibers themselves may be compromised. A qualified contractor will assess the integrity of the subfloor and the wood to determine if refinishing is a safe and viable option.
Ask an ExpertHardwood
How do you determine if a hardwood floor is a candidate for professional refinishing?
To determine if a floor can be refinished, check the thickness of the remaining wood above the tongue-and-groove. If there is sufficient 'wear layer' left, a professional can sand the surface. If the floor has been sanded too many times, it may be too thin to endure another cycle.