Ok, so my question around the perlcrete weight for the floor insulation was asked because I was thinking about using that as the base of a dry fit oven. As I got many replies, my wheels continued to turn, I recall reading that dry perlite is added for extra insulation. Since a dry fit oven is meant to be assembled quickly while sacrificing performance (at least the one I plan to make), would it improve the performance of the oven if I placed the bricks over a 3-4" layer of dry perlite and then poured dry perlite in between the inner and outer brick walls (first is firebrick, the outer wall would be any clay brick I could find. Lastly, I would place a sheet of aluminum over the roof firebrick (to prevent perlite from falling on the pizza through the dry fit gaps) and add a layer of dry perlite to this (with maybe something to prevent that perlite from blowing away (more brick or another sheet of aluminum). So I know this idea is well outside the box, do you think it would work, would it be only marginally better than just a simple dryfit oven with no insulation, or last, a complete waste of time. I did build a dryfit a few months ago and the pizzas that came out of it were great but it had to be recharged between pizzas. Anyway, interested in any ones thoughts.