Weatherlawyer wrote:

Put a row of bricks on edge to get 4 inches off the ground and a slab
of slate or garden tile or paving to raise it a little more. Pack it
level with sand and cement (4 to 1 & a fairly dry mix) to get it level.

You mean pack the level mix on top of the tile/slab? Or inside the
hollow formed by the bricks and tile? This will require many tiles...

Dan