Castable Pizza oven Smoker combo

[deejayoh]

Vermiculite is an insulating material, not a refractory material. Not sure where you are getting the idea that its a good material for a pizza oven, but it is the opposite of a good material for a pizza oven. You want a material that retains heat.

[fergo]

Hi all,

Im new to the forum but have read many posts on here. I have been exploring making a pizza oven from vermiculite similar to many that have been made on youtube.

However, my concerns are this:

as i want to use this as an oven from time to time as well, vermiculite wont have the thermal mass to retain the heat? if im reading all this data correctly.

So i was thinking, what if i8 make the outer cast as in the youtube videos out of vermiculite and then use this to make an inner mold of castable refractory?

If i was to do this how thin could i go for it to still retain sufficient heat / strength to hold up to heating and cooling ?

I was going to have an offset fire box for the smoker combo part just in case people are wondering and two doors one for when im smoking (inner door) and and outer door for other times.

The reasons i am considering this path as i quite like the idea of casting the oven chamber rather then bricks, in addition bricks are challenging to get in Brisbane, Australia and or are very expensive.

So i guess to summarise my questions

1) should i just build this from vermiculite? or the vermiculite refractory shell combo?
2) if not how thin can i go to retain the heat for the inner shell? bearing in mind it will have an outer shell of vermiculite and probably a heat shield inbetween the shells.