Extra door upstairs

[Mark Forest]

On the second floor of my single family rental home there is a door that exits to an outside flat rubber roof. The roof is only about six feet wide. If one were to take a long walk on this short roof they will fall two floors to the backyard. There is no railing.

I was thinking of just putting a deadbolt lock on the door and keeping custody of the key. The door is not an integral part of the house, and fire escape could be obtained through windows just as if the door was never there. Do any of you think I need to do more? Should I require some kind of waiver stating that the tenant should not attempt to force the door open?