The paving blocks didn't fit in even numbers. The blocks were not a full 8"x16". That added up to a 4" gap. The gap was left along the east wall and the south wall. It was filled with pieces of broken paving blocks and sand. The east side will have a table or countertop covering the gap and the south side was only 5' in length and this extra room on the south side will allow full sized paving blocks to be put over the threshold (under the door).