I am planning a decking project in my garden to cover over some old patio slabs.
The problem is the slabs have been raised by the roots of a tree and some are raised up by as much as 3 inches in areas.
I would like to keep my decking project simple as I am not very skilled in DIY but I would like my decking to be level (with a little dip for water runoff).
How do I prepare this surface to make it level for the joists?
Approximate area is 3metres X 7 metres.