I estimated pretty well how many slats it would take to cover 10' and ran out of my first load of lumber. It occurred to me that, if the rain could wash away my wood chips, my boardwalk might become a floating raft, so I drove some stakes into the ground and screwed the 2 middle slats to them to hold the whole thing in place. I did that a couple more times with each section. I also overlapped a slat, screwing it into the back end lath of one 10' course and the front end lath of the next 10' course, to hold the whole path together.