Some quick questions

[Samsch88]

Hi everyone & thanks for having me!

We recently started construction on our home built wood pizza oven. The base completed just yesterday. All square and level and now onto a 100mm hi strength concrete base.

My question is I see some people start the first course of brick stuck directly to the concrete slab. They then pour vermicrete or lay ceramic fibre sheet down, lay the fire brick floor and then proceed to laying the dome bricks. Is this right? How important is it to to pour the vermicrete or shape the ceramic fibre sheet down (cut to shape of course) and build the first course up from that?

I challenge starting the first course up from the ceramic fibre board or vermicrete because should it ever be compromised, the actual dome itself therefore too would be compromised.

Just after some some thoughts and best practices. Thanks so much guys, take care

Sam

[UtahBeehiver]

The oven wall and floor need to be completely isolated from the concrete hearth, in other words, you do NOT, start the dome wall on the concrete hearth. It will act as a heat sink and dome will lose heat transmitted down through the hearth. Have you reviewed or purchased the eplans from Forno Bravo? They are cheap $3 and a good baseline for design and construction.

[Samsch88]

Thanks Russel, I have purchased that but I guess my concern was will the ceramic board sheeting cope with the weight of the dome. I understand that the compressive strength of the material is excellent however I had to ask! Do you suggest Vermicrete over the ceramic fibre board or both together? What’s best practice?

[modified9v]

You do not want to get the fiberboard wet... therefore you would do the vermicrete first, then the fiberboard. Believe that is standard practice. The compressive strength is very good as you state... unless you get it wet.

I didn’t go with vermicrete (not available here)... Only one 2” layer of fiberboard. In the picture attached you can see the left side of the vent chamber arch has sheered from the vent floor. That ceramic fiberboard got wet when my tarp ripped and water got to that corner.

If I had it to do over I’d have built my vent chamber on the hearth stand and the vent floor area would float on the fiberboard.