Cooking directly on concrete

[GTA]

Hi, long time reader, first time poster...

Quick question:

Can I pour/cast a cooking deck of refractory concrete and cook directly on top of it? What are the drawbacks of this over cooking on firebrick?

Thanks in advance

[azpizzanut]

Hello GTA,

Sure you can make a cooking floor out of refractory concrete. Just how satisfactory it will be is the question. Some of the very small portable residential ovens have a refractory concrete floor but getting specific information about mix design and content are lacking. There are many refractory products available from numerous manufacturers. Perhaps someone who has had success making a cast floor could make a product recommendation.

A friend sent me an old post about a commercial oven that had a cast floor that developed a bad spot after it was used for awhile. Search this forum, or possibly someone will remember and reference it. This is an area you might research with refractory manufacturers if you want to try it. Also, refractory cement is generally expensive and you might want to do a test to see if it performs the way you want it to before spending the money.

Several caveats, being refractory concrete does not guarantee that it won't ever crack and if it does it may become uneven or difficult to repair. You can't replace a cast floor as easily as a firebrick. On the other hand, if you find a successful product you can share your experiences with forum members so we can develop a knowledge base. It sure would be nice to to have that information at hand for others to review.

Cheers,

[azpizzanut]

GTA,

I found it !!

Look at the FB forum for "Commercial Pizza Ovens" and locate the post by AndrewPizza. It is near the top.

To be fair, commercial pizza ovens may have to follow local food prep regulations which require extraordinary efforts to resolve if there are problems. This reference is only intended to give you an idea of one users experiences. There are thousands of modular commercial ovens and very few reported problems.

Cheers,

[Tscarborough]

The castable refractories that I have experience with would not be suitable for the use. They are not hard enough and are brittle. A kiln fired refractory tile is a whole different beast.

[dmun]

I think refractory concrete is concrete, if you are scraping fire and cooking tools over it you are going to be scraping the chalky surface loose. Some commercial ovens are required to have a seamless cooking floor, hence their use of this inferior (and expensive and hard to work with) material.

[C5dad]

We use a refractory mix at work all the time - I work at a copper smelter. There are way too many variables to count on the hardness and durability of any particular mix. The thing is, the better the wear, the higher the chromium content. Chromium is not good for you as it is the hexavalent type. There are also some other goodies as well.

In our application, we jackhammer the molten metal transfer system - known as launders - when copper matte or slag freezes on them. After a while, the chipping takes its toll and then the launders are removed and a freshly cast and cured launder is installed. No patching unless it is due to an early failure and waiting for the other launder to properly cure.

So, in a long answer, dont do it - high maintenance since you will not be using the high strength stuff for health reasons.

CW

[GTA]

Thanks for the replies.

Unfortunately, your replies seem to confirm my suspicions that a castable floor would not be very hard wearing.

I'll keep thinking.

[azpizzanut]

Hello GTA,

Stick with your original idea. There are a variety of refractory concrete mixes available from manufacturers and some will be suited for "High Abrasion" environments. After all, you will only be scrubbing the floor with a pizza peel. I don't want to encourage you to use that type of concrete for the cooking floor if you have an alternative. But it would be useful for other areas of an oven. Pursue your idea of a cast oven and maybe cover the cooking floor with "split" firebrick. It is not actually split but made half the normal thickness by the manufacturer. You can have your cast oven with conventional cooking floor if you design a plan for it.

If you intend for your oven to be used for commercial purposes then you may still have to deal with regulations concerning a seamless floor. Do your research into what commercial builders might be using. I don't expect them to be giving away proprietary information but you can research the issue and contact manufacturers representatives to discuss your needs. They are normally happy to discuss new uses for their products and a sals rep may take a personal interest too.

Cheers,