Now that the two part slab is done, it’s time to lay out the oven floor. Having already determined that my oven diameter is 38,” I mark a center line and begin to lay the bricks. Something that is often overlooked is the pattern of the brick. Consider the fact that you will be sliding a pizza peel into the oven…. a lot. The last thing you want is to see your pizza masterpiece fly off of it and land upside down on the floor because your peel was stopped suddenly. Lay your bricks at an angle to help prevent this. I chose a 45* herringbone pattern because it’s my favorite and in my opinion, pleasing to look at. But you can do a running bond on an angle too. If you do get any lippage, then you can use an angle grinder to sand the edge down to level.
In this picture you see the floor is laid wider than the wall of the dome..this was done because the brick was level and there will be no mortar between the first course and the floor. Also, the floor bricks are laid on a bed of sand mixed with refractory material (we used the slag from cutting firebrick). This mixture was used to create a level surface to lay the brick, and once dry, would allow the brick to expand and contract. There is no need to set the floor in refractory mortar. The sides of the floor where anchored by mortar on the outside diameter (not bedded) This is not necessary, I just wanted to use the extra mortar up. Setting the hearth floor inside the dome makes changing out the brick easier, but the chances that you have to replace the whole floor are slim to none if you use refractory brick. I recommend cutting in the floor if you are using soft red brick, Terra-cotta or Italian Biscotti tile.