We are practically on solid limestone, so burying wire is not an option for me either.  I also put down an apron around all my coops and runs, but am using welded wire.  If a raccoon can rip through chicken wire attached to a fence, it can rip through chicken wire on the ground, even if it is staked down.  Chicken wire also deteriorates & rusts after a while so becomes weaker. 
If you have small predators, like weasels & mink, that can slip through the holes of welded wire, attach hardware cloth underneath it, then stake the welded wire down on top.
	
		
			
		
		
	
				
			If you have small predators, like weasels & mink, that can slip through the holes of welded wire, attach hardware cloth underneath it, then stake the welded wire down on top.
 
	 
 
		 
 
		 
 
		 
 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		