Insulation between brick and concrete slab

[Joe Curley]

I have read and studied design and materials and decided on the size and type of pizza oven I will build, I understand the need for as insulated an oven as possible. My question is, the base of the oven will be insulated and the exterior of the dome but the bricks to form the dome cannot be laid on vermiculite as it is not load bearing, if the bricks are laid onto the concrete slab the heat will be lost. Is there a solution that I am not aware of?

[Gulf]

5 to1 vermicrete has enough compression strength to support an oven. It just needs to be supported from underneath.

Edit: Corrected under floor vermicrete ratio

[david s]

A10:1 brew is about 1/4 the strength of a 5:1 brew. So, 5:1 for under floor insulation and as lean as 10:1 for over the dome insulation which is not load bearing.

[Gulf]

Oops! You’re right David. Thanks, I will correct the post.