I think this has a lot do with the number of times have you fired the oven. Even though the oven has been sitting for some time, and has been cured, it will take a series of growing fires to drive out the final moisture and really get cooking. I have gotten to where I can tell how well a Forno Bravo customer has cured and fired their oven when I meet them to cook in their oven the first time. An oven that still has moisture in the bricks, mortars and concrete just doesn't want to get hot.
On the insulation topic, I think you will want to do something around the oven. It will help the oven hold heat, and also, when the oven is cured and you are having hotter, longer fires, the exterior of the oven is going to get hot.
James |