Joined: July 2004
||Posted: 07 April 2018,14:21
Millstone grit only ever comes as setts. You do get the occasional MG cobble, but they are occasional, and never in large quantities.
The definitions for setts and cobbles can be found here. In short, if the stones are dressed or worked into rough six-sided lumps of stone, they are setts.
Then, the build-up depends on just what you have and to what use you plan to put it. If these are setts, as I suspect, then there is a prcedure to determine the build-up that is based on the size of the setts and the likely traffic usage. If you really are planning on putting a truck over it, then it will need to be a considerable build-up, and would most likely require a bound base as well as an unbound sub-base.
Determine just what it is you have and plan from there.....
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