About a year ago I laid a base for a shed. The base was concrete paving slabs laid onto a base of dry mixed ballast & cement. I now intend on moving the shed to the bottom of the garden, so am therefore left with just the base. As the slabs are not particularly attractive I want to lay new slabs over the top and then build a brick BBQ on top of that. Now here's my question.... Would the existing base plus the new slabs on top be sufficient or do I need to pull the whole lot up and then dig out a few inches and lay a solid concrete pad. The thickness of the first option I guess would be around 5-6" if I take into account the base mix plus the two layers of slabs. If I have to go for the second option, what depth should I aim for (concrete and hardcore inclusive). Whilst I don't want to cut corners, neither do i want to cause myself unnecessary work. Hope this make sense, cheers for any advice.