We are in the process of digging to expand our veranda with approximately 12 square meters of extra decking. It's quite a bit of digging that was required to get to where we are now, but I think most of the digging is done.
This is approximately what we want to build (the yellow represents the existing veranda):
We have dug down to make room for the following:
28mm board
145mm beam
3mm tar paper
50mm concrete slab (which we got for free)
50mm 8-16mm gravel (we think 50mm is enough for ease of work) Total 276mm (but expect to place some spacer blocks as we dug a bit extra).
This is how the surface looks now:
As you can see, I've placed some beams to keep track during excavation so that we reach a somewhat correct depth.
Now, I believe the plan is as follows:
Level the ground and make sure it doesn't slope towards the house.
Use a compactor
Lay down landscape fabric
Add gravel and rake it out
Use the compactor again
Lay slabs
Build the framework and adjust with spacer blocks to level and align with the existing decking.
Does this sound right?
The tricky part that I mainly need help with is how to succeed with point 1. Now that we've dug out, it's quite uneven everywhere and not flat at all. The ground is hard (lots of clay), so simply using a leveling board doesn't work.
Pad on the gravel, just make sure to adjust the filling depth/pad; a 100 kg pad hits about 10 cm down into the material.
This assumes you have an undisturbed excavation bottom that is already hard.
