The choice between oil and varnish will depend on the desired effect to harmonize the staircase with the existing floors. Oil is a practical solution for its ease of maintenance and durability. To refresh the staircase, simply clean and apply a coat of oil. On the other hand, varnish requires more work, as the old varnish must be sanded to create the necessary adhesion for two coats to be applied at intervals of 2 or 3 hours. It is important to note that there should not be any bare areas of varnish. If there are, the entire staircase will need to be sanded and varnished with at least three coats.