The Ceramic Fiber Board (CF Board) is great for what it’s designed for - but is it worth the extra expense?
You have to order the board (typically 2") and have it freighted to your location. We say “freight” as carriers like UPS and FedEx no longer ship the board as it is easily damaged in transit. Secondly, when the board arrives you have to cut the board to the correct size - hope you ordered enough! Third, you just paid a lot of money for that board when Vermiculite / Perlite or Insulating Castable could provide identical heat retention properties for much less $$$.
BrickWood Ovens is focused on bringing you the ability to build an awesome wood fired oven - at a low cost!! One of the ways to keep costs down is to keep out the expensive stuff that adds little value. If you are going to spend extra dollars on insulation, purchase a second roll of Ceramic Fiber Blanket and wrap your oven with a couple of extra layers. You’ll get more bang for your buck with more CF blanket than CF board.