Ray,
I have two options (most likely is the first one):
- Bunnings concrete blocks 400x200x200mm, 2m above existing concrete slab and ~1m deep (see drawing).
- 3m, ø350mm Sonotube or equivalent, filled with concrete.
I intend to use
existing steel pier (it is now in our Melbourne backyard).
I plan to finish this by end of month, depending on concreter's availability.