I know the size of the cover itself, 18X34. How much of a deck  cover area do I need to inset the anchors into the concrete. My deck is narrow approx 3 feet fom the coping edge to a lawn. Before I purchase a solid cover, I need to know the total space needed from anchor to anchor on the opposite sides. I would appreciate your response to my inquirey. Thanks.

Joe D'Eletto