It's been a while since I've updated this thread, but it's getting close to being finished. I ended up buying a 3-piece cast concrete unit from a guy about 1-1/2 hours away who builds and sells them. Very nice design and basically the "easy button" when it comes to a wood burning oven. I could have spend a week miter cutting firebricks to make the dome, but I don't have that kind of time in life.
I could have left well enough alone and just put the damn oven on the countertop and been cooking delicious pizzas already, but no, that would have been too easy. While looking around on the interwebs, I found a wood fired pizza oven building forum. Yep, who knew! Turns out, building these things is a thing and a bigger thing than I would have ever imagined. What a rabbit hole I've gone down with this "weekend project"!
It turns out that not only can you make pizza in them, but if built properly, they can retain heat for days for baking. It's pretty impressive and apparently quite scientific. So, I did LOTS of reading on how to properly build, insulate, enclose and finish an efficient oven. Along with all of that comes the hours of time and considerable expense to do it, do it only once and do it correctly.
First was calculating the proper height for the opening of the oven. It's kind of important since things cook so quickly you really have to keep an eye on them. If the oven were at countertop height, you would be hunched over constantly to check on the progress. Next was beginning construction of the enclosure, which was done with metal studs due to the heat exposure. That part was pretty easy, just some tin snips and self-tappers. Then the science comes into play. I installed 4" of calcium silicate heat insulation board under the oven base. This allows heat to be retained in the oven bottom and not soak into the countertop. I then had some friends help carry the 3 pieces of the casting and set them into place. Once the 3 pieces were mortared together, the whole dome was wrapped in 2" of ceramic blanket insulation which is heat resistant to 2300*. The insulation isn't cheap, but if you're going to do it right, it's a must.
After this, it's time to enclose the structure in 1/4" Hardie Backer Board(cement board) and figure out how to finish the exterior.
After the entire thing was "glued and screwed" together, I asked questions to the pizza building forum gods and they suggested that filling the void with loose insulation would help even more with heat retention. So, out comes the saw to cut a few holes in the roof. I bought a few bags of Perlite and proceeded to fill the entire cavity as much as was possible.
Now it's time to make it look good. Since the traditional ovens were made of brick, I wanted that look. I found and bought a pallet of "vintage" reclaimed bricks. They came from the Lehigh Railroad repair garage in Sayre, PA that was built in 1903.
Here comes the fun part. It's time to try my hand again at masonary work. This won't be pretty I can assure you, but will look "vintage".
The weather was nice yesterday and we got most of the brick work was completed. I forgot to take pix and it was dark by the time I finished. Hopefully we get some decent weather tomorrow and Tuesday and there's an outside chance I can get the masonary work done. Fingers crossed.