HI
my yale deadlock contains a template for positioning of the lock, however, the template shows one side of the door thicker than the other (that is front to back) and the template itself is thicker than my actual door; all other diagrams eg on line, diy manuals etc. show the lock centered in the doors thickness. My current mortice lock is also centered. I am adding an additional lock, not replacing the existing one; can anyone explain this?
many thanks if you can>