Pizza OVen Base Insulation Question

[retroray12]

Hello,

I am making my pizza oven and was wondering if I would be able to get away with only using FB board under the oven for insulation or is Vermiculite required? was thinking of doing 4" of FB board.

Thanks

[UtahBeehiver]

Yes, p or vcrete not required with 4" CaSi board but you need to mitigate and water seepage that can get into or along the concrete hearth since CaSi is very water absorbent. You can do a search of builds on how this was accomplished. Have you downloaded and studied the eplans from Forno Bravo?

[retroray12]

Thanks Utah,

Yes those plans have been extremely helpful. From what I found searching in another post you mention drilling hole in the hearth and /or foam glass. Would it be smart to do both, or would I be good with one or the other?

Thanks

[UtahBeehiver]

Weep hole in the hearth is your best option, typically water migrates from the hearth surface and a weep hole will water egress out. Water will not migrate up through the FoamGlas as I mentioned it is hydrophobic.