Keeping floor warm

I’ve made pizza about 10 tens now since finishing my oven this fall. I’ve read some of the other tips about keeping the floor warm. But it got me to wondering. how to commercial pizza ovens keep their oven floors warm all day long? I thought the initial step of spreading coals all over the floor brings it up to temp. Eventually it will cool even with a fire going in the back. Right? I never see the guys at Blaze Pizza spreading coals across the floor though.

Just in my research of this whole process, I have found that the insulated layer under the fire bricks needs to be at least 4 inches for heat retention longevity. These instructions only call for 2”. I have made an oven with 2” installation layer and it works well but definitely not long term cooking. You would also have to consider a damper in your exhaust stack. To keep the heat in. Then you have to address the door and escaping heat. A bad ratio of insulation can also have an affect on retention as well, if you made your own mix.