I am in the final stages of putting together my oven, I have borrowed the manufacturers oven that is on a trailer while I was building mine and I find the cooking floor to be too hot. They recommend vermicrete or board insulation directly under the cooking floor, the cooking floor is high alumina content tiles. I think its too hot and it burns the bottoms of my pizzas long before its cooked. I am thinking of adding some bricks on top of the insulation but under the cooking floor as I pour the insulation, my thinking is that will add some mass to the floor and yes it will stay hot longer with mass but it might cool it a little by giving the heat somewhere to go. The builder does not recommend that by the way and says you put the pizza on the floor and after 30 seconds lift it up and hold it in the top half of the oven and let the top cook. I don't like that technique, I never had a problem at my old house with my Mugnaini but that oven was too small.
Looking for suggestions to cool the cooking floor while I am still in building stages. I am putting together a pre-fab brick oven, not building from scratch.