I am going to build a pavilion over a concrete slab and I am wondering what would be the best way to set up the footings. I was planning on using steel column bases set in 12 inch sonotubes. There will also be a concrete slab under the pavilion.
I am exploring three options.
The first option would be to first pour the footings (12 inch sonotube, 4 ft deep) at the final height of the slab. Expansion joint material would be placed around the footings before the slab (4 inch thick) is poured around them so they are independent of each other.
The second option would be to bury the sonotubes (4 ft deep) and pour the concrete for the tubes and the slab (4 inch thick) at the same time with no separation.
The third option would be to pour a thicker slab (5 to 6 inches thick) with no footings and set in the steel column bases when the slab is poured.
The second and third options would require less work but to me it seems like the first option would yield the best result.