I have wear on just one small area of a room- where my desk chair rolls back and forth while I'm pounding this keyboard. The finish is only 4 years old, has 3 coats and still quite nice except in the area where my chair rolls around.

I need to refinish the area. My questions are:

Will I need to sand down to bare wood and redo the stain AND finish? Or can I just screen down the finish and apply fresh finish coats?

Can I screen the area in need of refinishing and just redo that area, or will I need to do the whole room?

Once this is done, I WILL purchase a plexiglass floor saver. Wish I had when I put the furniture back in the room...

Thanks for any guidance,

If you havent worn down to the stain in the desk area, you may not need to re-sand. Try buffing and cleaning the worn area, apply one or two coats of finish, then buff entire room and apply a fresh coat through-out the room.