Hearth slab and oven floof question

[GypsyPicker]

Hi all... newbie here who may have goofed...

I'm building a WFO in a picnic grove behind my tavern. My primary use is to make pizzas some evenings all day (if possible) on weekends.

The hearth slab is curing now, but I put the vermiculite layer (~3") under the concrete layer (~3") which seems to be out of favor due to excessive thermal mass.

My questions:

1) Should I leave it as is or add another insulating layer on top of the concrete? If so, what material and how thick?

2) Should I make the hearth floor 2.5" or 4.5" thick?

Thanks in advance, I look forward to your responses and hope to contribute photos and lessons learned along the way.

~Gypsy (aka Scott)

[GypsyPicker]

I guess I'm going to add another 4" of vermiculite concrete for the oven floor and go with 2.5" floor height -- seems to be what most here have done.

[Tscarborough]

That sounds like a good compromise.

[fxpose]

That's exactly what I would do too at this point, although that will add an additional 4" of height to your oven.....if that matters at all, especially for someone shorter than you operating the oven.

[eprante]

If you are worried about the oven being too high, consider using the 2" FB board instead of the vermicrete. That will save you 2".
Eric

[Neil2]

"although that will add an additional 4" of height to your oven"

Try it at that height. Many prefer a quite high floor so they can see in with out bending over. If it is too high you can always raise your patio !

[Raffy]

I thought my oven was high enough but I still have to stoop over to see the back of the oven but it's not an issue for me. Although I have to say that the 4" vermicrete is vital because you dont want the slab sucking away the heat from your cooking floor. Having a lot of thermal mass will make it difficult for you to get to pizza temperature for your cooking surface.

Unless you are doing a lot of retained heat cooking I'd leave the floor at 2.5" rather than 4.5". It's hard enough as it is to get the floor to pizza temp.