Vault style firebrick oven cladding

[jgiddens]

I am building a vault style oven with standard firebirck. As the cladding on the outside is supposed to support the arch design of the oven, why would you use portland cement which cracks and looses it's strength when subject to temp. Would it not make sense to clad the outside with a couple inches of perlcrete to reduce the temp level to the portland cladding. This would seem to allow for some expansion/contraction of the oven without cracking the concrete cladding as well. You could add a few more inches of insulation outside the concrete to serve to retain heat. Any thoughts.

[dmun]

I'm not an expert on barrel vault ovens, but I think the exterior cladding, directly over the fire brick, serves to add additional thermal mass, and strength to the dome. It goes under any insulation you use. Having a thin perlcrete layer under this cladding would defeat both purposes, aside from being hard to apply that thinly, and not being nearly thick enough for your primary insulation.

[n2iko]

The cladding on the side also acts as a buttressing of the arch. In that case it is part of the design. It is a massive force on the putside wall.

[Mojoe]

As far as heat goes, the insulating layer serves the same purpose whether it is placed over brick or concrete cladding...keep the heat in. Any cracks in the cladding are covered up by the insulating layer same as if you had any cracks/gaps in your bricks.