Foundation slab

[GuyT]

Hi,
I have been reviewing the instructions under the pompeii oven plans and reached step 1 - and already have questions ^^
In my garden, I would like to build the oven above existing flooring. The floor tiles are around 3-4 cm width above flat earth.
1. Do you think i can skip the foundation part, as the floor tiles might suffice as strong foundations?
2. Would you recommend to remove the tiles and build the foundation directly in contact with the ground?
3. Will you recommend to build the foundation above the flooring?

Thanks,

Guy.

[UtahBeehiver]

These ovens are really heavy and need a proper slab/foundation with appropriate subsurface material and preparation, ie structural fill, ie road base/grave. and compaction then at least a slab 4" thick with reinforcing rebar and wire mesh. Don't scrimp on this. So 1 and 3 are not really good options and 2 is kinda of there but you need to dig below the bottom of the slab for structural fill. The only possible option of laying directly on the existing ground is if the ground is incorporated stone or bedrock.