Re-sanding the joints between the pavers is a crucial part of restoring pavers. If you allow a company to pressure wash your pavers, make certain the sand is replaced and with the proper sand (no play sand). Your pavers strength comes from the sand in the joints. Without being replaced your pavers are allowed to shift and move which will cause uneven pavers. Proper sanding will leave the surface of your pavers clean (not sandy) with the joints not being over or under filled.