Most engineered wood floors are pre-finished at the factory, which eliminates the mess, extra time and vapors associated with applying the finish coats on the job-site. Pre-finished wood floors are ready to be walked on right after the installation is completed. No long waiting for staining and applying coats of finish. Most factory applied finishes are UV-cured with ultra violet lights which creates a much harder finish than a job-site finish. In addition, the manufacturer can apply more coats of finish as well giving added protection.