I bought the top floor, so I can't go to the top to bask in the sun. What happened to the lock?

This requires a careful examination of the purchase contract signed at that time. Generally speaking, the roof of the community is public property, not the private property of the people on the top floor, and there is generally property management. There is a waterproof layer on the roof. If the roof is used frequently, it is easy to destroy the waterproof layer and cause water leakage on the top floor. If your purchase contract states that the roof belongs to the top floor user, you can knock on the door and enjoy the sunshine.