We had a large area of patio that had started sinking and CRC Concrete Raising and Repair repaired it and filled in the cracks. There was a little shifting afterward, and they came back to fix it according to their lifetime guarantee. They knew what they were doing and did a good job. There were six sections, one was rounded, and a very uneven walkway. I found them through a newspaper article that I clipped out. It wasn't cheap but well worth the money. We knew it had to be done and would never be able to sell the house with the patio in that condition.