I am in the early building stages of a pizza oven (and adjacent gaucho grill) DIY project. I am seeking some advice on how to finish my oven. My oven will be outside with no roof/cover.
I want to avoid the use of ceramic fiber blankets, boards, and the like. I will be building a barrel dome out of fire brick and figure I would use about 4" of perlite concrete for both the hearth and dome insulation. I will be laying the firebrick at the hearth such that I have a 4.5" thick hearth (I am convinced I want more thermal mass than 2.5"). I am not yet sure of the ratio of perlite to cement for the insulating layer and I am open to suggestions.
My primary question is: is it sound practice to stucco directly over the perlite concrete at the dome (perhaps with lath so as to not have any expansion/contraction in the insulating concrete telegraph through to the stucco)? Does the perlite concrete have enough structural integrity to be a base layer for the stucco? Is it better to install a few inches of standard strength concrete (with reinforcement) over the perlite concrete and then stucco over that? Any shared experience will be very helpful.
I'm already full steam ahead with the base dimensions, so the ultimate thickness of the oven walls will affect what my actual oven dimension will be.