Building dome on firebrick floor

[englishbob]

Hello
may blockbstand is ready with the concrete hearth nicely set
reading the fornobravo instructions it says to set the firebrick cooking floor on to a wet sand base
so my question is do I build my dome walls on top of the firebrick floor or directly on to the concrete base?
it looks like on the firebrick base in the photos? Just need some reassurance before mixing up the mortar
TIA

[UtahBeehiver]

What is your floor insulation? The dome does NOT sit on the concrete hearth if you look at the cross sections in the FB plans. The dome can sit on the floor bricks or around the floor bricks but must be insulated from the concrete hearth.. Also the sand/fire clay bedding under the brick floor but above the floor insulation is for leveling only

[englishbob]

Thanks for the reply Russell
so it appears that I have tried to miss out the insulation layer between the concrete and the brick floor.
I see from your excellent pictures that you used square insulation, what is this please ? Building on a budget!
cheers
bob

[UtahBeehiver]

Out of town right now so not checking forum. Quick answer, CaSi board and foamglas