I'm planning to build my own wood fired oven, and have come up with an initial plan which I've pretty crudely drawn up in Sketchup.
In short I want to be able to cook a variety of things, not just pizzas, so I went with a box shape. I've already got the base built which is a wooden frame and part of an existing garden bed structure, and the door would be insulated. I plan to put a removable shelf in, plus some holes in each side to put a rotisserie through and just fill with threaded bolts when not in use.
But I'm really not sure how to handle the insulation/concrete mix. I was planning to have the base as a concrete slab that sits on the aforementioned wooden frame, with a slate slab embedded in the bit that will be in use, as I have some left over from my fireplace and assume slate is better than concrete as a cooking surface (is that right?)
So does anyone have any advice or know of any info regarding insulation/heat loss properties of concrete mixes and cavities? I really want to be able to slow cook, so retaining heat is important. In my model I've done a cavity that i'd fill with insulation but it'd be much easier to only have to cast it as one piece!
1) Is there a way to make the equivalent thickness of concrete as effective as splitting it with a cavity if the correct mix is used, and what would that be? 2) Does my mix really need to be heat/fire resistant? 3) Are there any specific flaws/room for improvement anyone can spot with my initial design?