A fill blocker to block a gap between two paving stones each having a side face facing each other and an outer face wherein the fill blocker prevents filling material inserted between the paving blocks to escape through the gap. The fill blocker comprising a body comprising an interior face having two abutting portions and a fill-blocking portion therebetween; and a holding component extending from the interior face adapted to be wedged between the side faces. The fill blocker is adapted to have the holding component inserted in the gap between the side faces and be wedged therein with the abutting portions abutting the outer faces of the paving stones and thereby blocking the gap.