Hearth Design Philosophy Getting Started Discuss Hearth Design Philosophy in the Pizza Oven Design and Installation forums; I am getting ready to pour the hearth but before I do, I have a question. Is it necessary to ...

[bolex16mm]

I am getting ready to pour the hearth but before I do, I have a question. Is it necessary to have an ash slot? I noticed on some of the other designs that they do but this design does not. Thanks

[RTflorida]

I didn't put one in, can't say how useful it might be. I do know that ash removal is not an issue if you have a brush and shovel.
I have seen mention that an ash slot can actually get in the way when loading pizzas or other baked/roasted goodies.....having done all of the above, I can see how it might get in the way...excluding pizza, I tend to sit everything on my landing when loading and unloading.

RT

[Hendo]

I have included an ash slot with an ash pit below, but can't yet comment on its usefulness or whether it gets in the way etc. I thought it seemed like a good idea at the time, and figure I can always fill it in if it proves cumbersome. Difficult to do it the other way around ....

My landing will extend some 12" in front of the slot when finished.

[james]

I have an ash dump on both of my Healdburg ovens, and never use them. The also can get in the way when you are doing fire in the oven cooking -- as opposed to retained heat baking.

They take some effort to install, so on the whole, we recommend that you don't need one.
James

[bbell]

Sooooo.... For the hearth insulation would you say that one layer of InSol Board, on top of the supporting slab, should be sufficient and skip the vermiculite cement all together?

Thanks

[christo]

That's how I did it and it works great for me!

Christo

[james]

That sounds right to me. The structural concrete slab at the bottom, either 2" of FB Board or 4" of vermiculite concrete on top of that, and the cooking floor directly on top of that.

We have a good base of experience that 2" of FB Board will readily insulate a residential oven and you will retain all the heat in your oven and the bottom of the concrete won't even get warm.

Go for it.
James

[Dino_Pizza]

bbell,
That is exactly how I will be doing mine next month. If you look at Christo's answer above, and click on his link to his second page on his thread, (message #12? or something) you can clearly see a picture of his 5 blocks high stand, a 4" or so pour of concrete on that and then the 2" FB board or insulation board product that the oven floor bricks sit on.
Have fun on the project!
-Dino.

[bbell]

Dino, James and Christo,

My thanks toeac of you for the reply. Now waiting for a change in weather (above 32 deg. would be nice) so I can pour a slab.

Be well.
Bill

[kgmfq3]

Quick question about the oven floor. Do you sit the walls of the dome onto the cooking floor or do you cut the floor round like Hendo did and have the walls rest on the FB or vermiculite concrete? It seems to me that the oven would be more efficient if the dome walls sat on the insulating layer and not directly on the cooking floor.

Jay