The British tend to lay unit paving with mortar joints on mortar beds on a concrete base; this is often unnecessary, often ugly and usually leads to cracking. The paving acts as a heat sump, thereby contributing to the urban heat-island effect, and produces more global-warming gases.
It is also unnecessarily expensive. Flexible construction is the norm in the Netherlands and Germany, with sanded butt joints, a sand bed, and a hard-core base course.
Fundamental to pavement construction is the need to allow for movement of the soil: this can be done by designing a very strong, rigid structure or by designing a flexible one. For most pedestrian paving, the use of a 2 in sand bed and sanded butt joint will produce a flexible paving ...