Dome sizes measured out side or internal diameter ?

[paul600rr]

Hi quick question when people say they building say a 36 inch or 42 inch dome is this measurement from the inside cooking area ? or the measurements from the outside diameter of the first course if you understand what I’m trying to explain thanks Paul

[SableSprings]

Generally, the dimension is the inside (actual cooking floor space). The reason is that the oven wall & insulation thickness can vary greatly based on the cooking/baking goals of the builder...and folks primarily just want to know how much space they will have for their pizza, pans, or roasters.

[paul600rr]

Thank you that's clearer then for my build

[SableSprings]

A common mistake when planning a WFO build is to forget about how much "extra space" you need for the support hearth slab. Brick width, insulation, and outside finish all add in to the oven's final footprint. Most builders make the top slab even bigger than needed for the oven to create a little side space to set a beer while working or even bigger to set some toppings or a loaded peel. Really think about prep space in your plan. Good luck & again, welcome!