A door that slides is a pocket door. It uses rollers on an overhead track that is fixed into a ?pocket? in the wall on either side of it. Fully open, door completely disappears from one side of the wall. They are very poplular and good idea as resurgence in smaller spaces, like condominiums and townhouses. Pocket doors have also drawbacks and are not the best solution for every space. Here are their good and bad sides:

they save valuable floor space eliminating the room for traditional doors to swing. you need to have enough clearance in the wall framing for the door to slide on.
you cannot put any light switches or outlets in those walls (there?s no room).
The hardware for pocket doors is fairly stripped down, so you could be able to clean the framing in the wall.
Double-pocket-door privacy lock sets do exist, but they are not common and can be expensive…

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