Help. pre-cast oven plans and concrete recipe.

[sonomacast]

I want to build an outdoor oven (Pizza) and basically I have spent a while reading the books and studying the internet and had decided to have a go at using bricks and blocks however I have not laid a brick ever but by trade I am a shuttering carpenter (Formwork) so the obvious and easiest thing to do would be to build my own form (Mould)for the dome.
Concerns I have are, what sort of reinforcement do I use as I guess that steel re-bar would expand with the heat and crack the dome or is this not the case.
(How are the other pre cast domes manufactured?)
Does anyone know of any plans for a form to make pre-cast domes and also how do I make refractory concrete?
Any other info would be greatly appreciated. Thank you

[james]

Hello Sonoma,

Are you in Somona? We're in Healdsburg, where is it predicted to be 106F tomorrow. Ouch. We just got back from the Sierras, where it was a lot nicer (other than swimming in the Stanislaus river where the current was the fastest I've seen -- I almost got swept away).

You can cast your own oven, and there is even a book on how to make a Cobb (Adobe) oven. Kiko Denzer's, Earth Ovens. I've never done it, nor have I watched anyone do it, so my experience is limited to books and photographs -- and the adobe oven at Preston Vineyards. One downside of adobe ovens is that it really doesn't get hot, like a real pizza oven. I also don't know if they will last.

If you construct your oven dome using refractory concrete, the oven will perform better than adobe, but you still have the work of building the forms and getting the shape right (you would have to do a lot of cutting and bending to get a good form), pouring (would you do it in layers) and curing the concrete -- and that only gets you the dome. You still need to build the stand, hearth, cooking floor, vent, door, insulation, etc. I am not sure how likely a monolithic concrete dome would be to cracking. Putting lost of metal, such as rebar, would make the cracking worse. Something to think about.

One thing I have seen in the Mediterranean countryside are stone ovens. Maybe some will build a complete oven from "found" stone.

I always like to learn from other people's experience, which in this case has shown me zillions of brick ovens.

James