Repair pavers that sink below grade by removing the paver and adding more sand. Usually, sinking pavers are a sign of improper installation. Use a furring strip to locate the pavers that are below grade, mark them with a piece of chalk, and relevel each one individually. Other reasons pavers need repair include the growth of moss and broken pavers.
Pavers installed in damp areas with little exposure to the sun often grow moss. The growth makes them slick and dangerous. Remove the moss using a pressure washer. Repeat the procedure every six months to keep the moss under control. If the area is very shady, the application of a moss retardant helps to prevent growth between washing the patio.
Repairing a broken paver is similar to repairing one that is below grade. Use a large flat screwdriver to pry the stone from the paved area. Add more sand underneath if necessary to bring the new paver to grade, and install it. After installing the new paver, apply sand to the top, and use a broom to sweep it into the cracks surrounding the stone. Repairing broken pavers set in concrete requires breaking out the old block and tapping the new one into place using a rubber mallet. They sometimes require adding more concrete to complete the repair.