I am curious what you want kind of oven you want to use the firebricks for. I saw you posted about a rocket stove oven and also using infrared cookers for pizzas.
The reason I asked is because I used split firebricks for the bottom hearth and split firebricks in a steel pan to use as the top of the oven to make pizzas for awhile before the BS was purchased. Only limited sized pizzas could be made with that mod for the grill though.
In my opinion the BS does work really well for almost any style of pizza.
My idea is this, place the fire brick above the rocket stove 3 in's so the heat will distribute evenly.. Then have a pizza stone sit on the fire brick while I have an 11 gauge disc as the top to retain any heat from above. The sides will let some heat rise around the brick and make it to the chamber so as not to kill the crust and have the top of the pizza be raw.
If it works the way I'm hoping then I'm in pizza heaven but if not back to the drawing board for ideas. I think the idea is sound just never used brick for cooking and don't really have a grasp on heat distribution yet but I'm learning and that's half the fun.
I love making my own cooking gear and this is one of my tough ones because of the fire brick and not knowing.
I have found brick here and hope to have it Saturday, will post the build as I go. The brick is 1.40 per block not bad I think
Thanks for all the info so far