Re: Use of Vermiculite boarding under Fire Bricks
Posted by Eugene (24.62.119.242)
In Reply to: Re: Use of Vermiculite boarding under Fire Bricks posted by David
Heat in the concrete of the hearth slab, the sides, and over the dome is all necessary for heat retention. The firebricks themselves do most of the job, but I believe to keep the heat longer you need the concrete as well. That is why the hearth slab is poured so thick (6.5 inches).
In the Documentation of Rado's plans, he talks a lot about the concrete cladding and its use in oven efficiency and about how it only adds minimally to the heat-up time.