Construction, standards and environment
sub-base
In short and in plain language
The sub-base is the packed layers under a paved surface.
This can be paving, a terrace or a driveway.
It carries the load, drains water and guards against frost damage.
Once the work is done, you cannot see it. Yet it largely decides how long the surface lasts.
Definition
The sub-base is the build-up of compacted layers beneath a paved surface such as paving, a terrace or a driveway. It carries the loads, drains water and protects against frost damage. Once finished it is no longer visible, yet it largely decides how long the surface lasts.