vermiculate why

[love to bake]

Hi all yes i am another keen pizza oven fan. I am building the slab that my fire bricks will sit on. The instruction i am following say to use vermiculate in the top half of the slab is it just to make the slab a bit lighter.

Thanks all

[Neil2]

Re: vermiculate why

The vermiculate layer between your structural slab and the firebrick hearth is for insulation.