Paver Patio Repair
This paver patio was many decades old and had experienced severe sinking during that time. The pavers along the foundation of the house was tilted at a severe angle as can be seen in the third photo above. In addition to this obvious sinkage, water was pooling beside the foundation wall rather than going into the small drain. This made the space unusable in winter.
During excavation, it was discovered there was significant sand below the pavers. Typically 0.5″ – 1″ of sand is used as a base for paver bricks. In this patio construction, there was around 3″ – 4″ of sand. This excess of sand likely helped cause the dramatic sinking of the pavers. Similar problems can be seen on another property nearby built by the same builders.
To repair this patio, the excess sand was removed and roadbase gravel was put down. The entire area was also lifted a few inches due to how much it had sunk in order to bring it above the height of the drain. As the goals of this repair was to both fix the aesthetics issue of having such a sunk paver and the drainage issues of the drain not working, it was important to address both of these issues by raising the sunk areas. This time, only 1″ or less of sand was used before laying down the pavers.
One of the challenges during this was that the drain was itself in poor shape and was semi functional. It was too small and not put in the lowest section of the entire patio. The drain cover was also tilted for some reason and could not be fixed without replacement. The main challenge, however, was maintaining enough pitch relative to both ends of the patio while raising it enough to be higher than the drain. The way the patio was originally designed, the low spot was in the middle. This meant that both ends of the patio sloped down towards it. However, the middle part had become too low, lower than the drain that was placed off center, and so this presented drainage problems. The challenge was to raise the middle section enough so that it was higher than the drain and water would drain but at the same time, it had to remain lower than both ends of the patio or else water would collect in other places. To be honest, whoever designed this designed it poorly. There was no reason why the patio could not have drained away from the house onto the lawn that surrounded the patio on 3 sides. Instead they created this situation where water collected in the middle of the patio, the drain was too small and misplaced off center, and that a drainage pipe had to be involved at all.