Virginia Dawnswir

We are planning a brick arched pizza/bread oven. We want to insulate it well. We are thinking of using the cob oven rubble base with glass and vermiculite for the base of the oven, then laying the fire brick and then building an arch oven with smaller arch door and chimney. We will purchase the fire brick. Any suggestions on what type of fire brick to buy, we are in Virginia. We have a lots of new regular brick, should we put a second layer over the fire brick? Can we use cob insulation? We will have a cover over our oven. Should we just use cob and not bother with the regular red brick, or use both?

Looking at different plans for the arched oven. Any suggestions, book or articles to read? Thank you all for any help you can give!
virginia

We are exploring building a cob oven or a brick oven for pizza and bread. Cob was the first choice, but have been talking to some cob oven owners and they all complain about "spalling" especially bad when clay falls into gooey melted mozzarella. I am thinking eithe cob construction, using potters dry clay for a mix that might hold up better. If you have done this, what type of potters clay (I am a potter) and would using builders sand be good? Are there any additives that will make that first layer (inside of dome) stronger?

The other option would be to use fire brick dome or arch. I was wondering if cob with straw could be added over for insulation? Rather than going the fiber insulation route seen in many brick oven articles and videos.

If you are a cob oven user, how many years does the cob oven hold up under say, weekly use?

Thank you,
virginia