I plan to construct my oven from 3x6x9" fire brick on top of a 4" concrete slab. The bottom of the oven floor will be 2" high density ceramic fiber board with 1.5" fire brick on top of it. I also plan to have 2 layers of 2" thick 6# blanket over the top and sides of oven.
My question is, should the side walls of the oven be on top of the 2" ceramic board or would it be okay to have the side walls directly on the concrete and the ceramic board in between the walls and back, basically the fire brick would be a perimeter around the ceramic board?
I’m wondering if it would be better to have a 4 inch thick ceramic fiber floor between the concrete slab and fire brick cooking surface leaving the fire brick walls (underside of the walls) to be in direct contact with the concrete slab but butt up against the ceramic fiber board versus a 2" layer of fiber board that is under the floor AND the walls? I’m probably over thinking this but I’d rather be safe than sorry.
Thanks in advance!