Setting the cooking floor

[antwlo]

Hello,
this is my first entry in the forum. I just started building my pizza oven and I have a question...
I completed building the foundation, brick walls, and hearth. I'm at a point now where i need to start laying the firebricks on the hearth.

I'm using Cement fiber boards for insulation.

My question is...once I put the cement fiber boards on the hearth, do I need to put a layer of sand/fireclay on top of the fiber board before setting the firebricks or can I lay the bricks directly on the insulation boards?

[Gulf]

Antwlo,

Welcome to the forum. Cement fiber board is not insulation.

[antwlo]

thank you for the clarification. what about the need for the mixture of fireclay/sand?

[Gulf]

My insulation board was near perfectly level and even at all seams. I elected to not go with the clay and sand leveler. I only think it is necessary if the insulation layer is uneven. Is it "ceramic" fiber board that you are using for insulation? If it is "cement" fiber board, then I am afraid that you will be very disappointed in your oven's performance.

[antwlo]

I'm using "ceramic" fiber board, not cement. seems fireclay/sand are only needed to ensure bricks are leveled.

[ronfillius]

can you use just sand on top of the perlite insulation to lay the hearth brick, or do you need to use fire clay and sand? Also do you have to use a special food safe firebrick or is medium grade ok?