Refractory cement floor instead of fire brick

[Enricopalzzo]

Hi, long time reader, first time poster

I’ve been reading a huge amount and am in the process of building a WFO like many of you are or have undertaken.

My oven is a combination of refractory cement (not home brew) rated to 1300c and clay brick. I will be casting the upper section of dome refractory cement and SS needles, and then using clay bricks for the wall on the sides between the floor of oven and dome (standing upright) hopefully that makes sense.

My question is, I think I will have excess refractory cement left over, and was wondering if I can use this for the floor of the oven, building it to the same height as if I was using fire brick that I was going to use, and also with the addition of SS needles, should be up to the task? Or am I missing something?

I know It wont look as nice as fire brick floor, but I’m not overly fussed by this. Insulation below will still be FB type board, so I’m only debating the refractory cement v firebrick situation, which will save me a bit.

Thanks I’m advance for your help. This is such an amazing resource. Dean

[david s]

It is the floor of the oven that gets the greatest beating. Oven floor bricks are generally laid loose to allow for uneven expansion. The centre of the floor gets hot first and therefore also expands first. If you cast the floor in one piece, expect cracking. Better to have some joins if you can. It is also not easy to replace a cast floor like you can with loose floor bricks.

[fox]

You could cast your own fire bricks in a basic mould, you will get the best results from useing a very dry mix and vibrating the mould.
Of course the results will not actually be the same as a fired brick but you can make them any shape you like and just use an orbital sander on the side of your mould.
Home brew is very easy to work with, refactory cement is not!

[david s]

The aggregates you use with the refractory cement may also be unsuitable. A proprietary refractory castable would be a better option, but fired firebrick the best.