facts: house had carpet, removed carpet and had floors finished last winter. In spring noticed ruff spots on floor, called finisher said too much humidity is the cause. I have finised basement with dehumidifier and run ac in summer. Finisher used commerical polyurathene water base to seal floor. Any suggestions on how to fix ruff raised areas? Do I need to refinish floor again? Can I sand down finish and reapply poly again without staining it? DId doing job in winter effect the floor, too dry?