This gap will keep the pavers flexible despite soil movements. Also, the gap lets you add stone dust or sand between the stones, helping to lock them in place and reduce shifting. Another tip is ...

Pavers have been used for thousands of years ... After that comes a one-inch layer of bedding sand or stone dust, more ...

And we use a sand, it's a jointing sand ... We have to get the soil excavated to provide space for the foundation stone for our pavers. We dig down to about 12 inches of depth.