 Re: Topping off the bottom.
You can't have too much insulation...
I poured my insulating layer, then found it less smooth than I would have liked, so I skim coated it with mortar. I also believe that for home use, you can have too much thermal mass - the greater the thermal mass, the slower the heat up time. If you fail to adequately heat up the mass below the oven the floor will drop temperature quickly when you transition from your heat up fire to your cooking fire. Now, if bread is your primary goal and pizza will be an occasional indulgence, then more mass may be useful. I think the trade off between an inch more mass and an inch less insulation is probably not good for either pizza or bread.
by the way, beautiful work so far.
Marc |