In Mexico, we do our counters out of concrete, about 8 cm thick. The new oven will sitr on top of this counter, the base firebrick will be layed on top of the counter surface. Because the oven is quite large in diameter (36" inside, small for a pizza oven), half of the oven actually sits through the exterior wall (which is brick and concrete) and is outside of the house (but surrounded by a half-circle brick wall). If I build it this way, and insullate it then cover it in plaster, will the heat of the fire travel out through the concrete kitchen counter too much? Do I have to "isolate" the oven from the rest of the countrer on either side of it?