Hello all! I have completed my 33" dome and am heading into the last mile of vent and enclosure design/build and need some help as I try to seal this thing up before real winter precipitation starts here in what's been a dry northern California winter so far.

I initially found this incredible forum while researching foundation and hearth designs for a barrel vault oven following the A. Scott / Bread Builders approach, and the beautiful and functional builds here brought me over to the Pompeii design. For my intended use as a true extension of the kitchen with a healthy mix of roasting, bread baking and proper Italian pizzas, I wanted to go with a 30-33" dome with as small of a foundation as possible given my space limitations. After a couple early PMs with Gastagg, I dove in and have just wrapped up curing fires for the dome. Pictures are attached to bring you up to speed on the last few months of work.

At this point I am trying to lock down the approach for the vent/entry design and build and want to follow the current best practices. I'm planning on a 1-2" reveal, a 1" heat break, a 12-15" total depth of the entry and vent area, and utilizing the serpentine / curved vent feeding into 6" chimney pipe through a gabled roof.

* Should vent/entry floor and arches rest atop calsil board, or should the arches rest directly on the hearth?
* Following the question above, should anything be mortared to the hearth in this area of the oven? I like Gulf's approach of just mortaring the very front of the entry floor (the "threshold" in these images - https://get.google.com/albumarchive/...Lbsi5Kkh57P_QE)
* Is there a rule of thumb for the depth of the arches and the serpentine vent? Not knowing any better, I'm thinking of going 4" depth for the initial vent arch that abuts the heat break, leading into 5" serpentine vent, and then finished with a 4.5" outer arch.

Thanks so much for any guidance.