Final answer:
Yes, you can refinish an existing floor by sanding down the old finish and applying a new one.
Step-by-step explanation:
Yes, you can refinish an existing floor.
Refinishing a floor involves sanding down the old finish and applying a new one.
For example, if you have a hardwood floor that has scratches or an old worn-out finish, you can refinish it by sanding the surface and applying a new coat of stain and protective finish.