Monolithic Hearth Slab - Big Mike's Single Hearth Slab in Pictures

Opted to pour the hearth slab for this pizza oven - and the results are OUTSTANDING! If you wish to create a single / monolithic hearth slab, here’s a winning design!













































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That’s a beauty, Mike. Congratulations!

The proof is in the pizza, of course. But we know the work that went into casting that slab, and it’s an outstanding job that you’ll always be able to point to with pride.

Thanks for these great photos!

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Outstanding build!

For our own oven, we are going with a wider footprint (64"x64") and like the idea of a single slab for the floor. I’m thinking a couple pieces of angle iron slotted into the block for support under the floor would be a good idea. Beyond that, two questions:

  1. How did you design your forms? Were they screwed into the concrete block? Supported from underneath?
  2. Is there any insulating material like vermiculite in the mix? Is it necessary?
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Hi, Eric, and welcome to the BrickWood forums!

If you look at photos 4 through 10, you’ll see that Big Mike installed the pink polystyrene block on top of the first layer of concrete, weighted it down, then poured more concrete flush to the top of the polystyrene. That was the end of the slab pour.

From there, he pulled out the pink and poured in the Perlite/Portland cement mix per instructions.

The insulation in the slab is absolutely necessary, whether you are casting-and-hoisting a three part fab or casting in place. @Big_Mike did this the smart way (no hoisting), but he still followed the spirit of the design.

You must have the insulated section under your hearth floor or the oven will not perform as designed. Thankfully, mixing and pouring the insulating mix is one of the easiest steps of the process—it can even be relaxing! And using the recommended mix, with ingredients you can get for a song at a plant nursery or a big box store, is also very inexpensive.

Looking forward to your next steps, Eric, and hope we’ll see you here often!

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