Interlocking Stone & Pavers in Ajax

A sunken paver walkway, a driveway with a dip where the car parks, a patio that has gone wavy - none of that is the stone's fault. The stone is fine. What moved is the material underneath it, and it moved because it was never built to carry the load or shed the water. The shortcuts are always the same. Not enough excavation, so the base is too thin. Base material dumped and levelled but never compacted in lifts, so it settles under its own weight the first year. No geotextile between base and subgrade, so clay migrates up and gravel migrates down until there is no distinct base left at all. Then GTA winter goes to work. Water gets into an under-compacted base, freezes, expands, and lifts. It thaws, the material settles somewhere slightly different, and the surface is now half a centimetre out. Repeat that thirty times a winter for four winters and you have the heaving and rippling everyone recognises. The joints matter too. Once joint sand washes out, the pavers stop interlocking and start behaving like individual stones sitting on dirt. They rock, they shift, weeds root in the gaps, and the whole field starts to go.