Please see my updated image based on your advice, sub-base was reduced to 100mm.
So I have to create a foundation for the kerb bedding to rest on? I assume I make it slightly wider than the kerb bedding width. Is this drawing now correct?
Just to begin with the fact that I am a total novice when it comes to garden/building works.
Please see below my design and specifications for a simple ground level patio installation which will be level with the threshold of a rear alley which will be accessed via a gate. I have also attached...