Yesterday and today I finished up the forms for the buttressing/cladding layer around the walls of my oven. I used an old piece of 1/4″ plywood for the back wall, and I was able to re-use the 1×6 and 1×8 forms and other scrap lumber that I had used for the base and hearth slabs, so lots of money was saved. It was sort of a cut and fit type of project, but it came out very nicely.
overview of buttress form with wheelbarrow
These forms are used to help pour concrete between the brick walls and the edge of the hearth slab. This gives the oven more mass for heat to sink into. This will mean I’ll be able to bake longer and at a more even falling temperature. The mass along the side walls also serves to buttress them from the outward forces that the dome arch will apply. We don’t want our domes to sag, now do we? 
I used almost four 60 lb. bags of Quikrete. Had to scoot over to Home Depot for the last two. I’ve found that a bag of concrete doesn’t actually go very far – you always need more than you think.
concrete cladding poured along side wall
Thought you might like to see some of the tools etc. that go into brick oven building. The workplace picture shows the oven (of course), my little red wagon, our orange wheelbarrow, the miter saw, two drills (one for drilling pilot holes and one for driving screws), my mortar hoe, a small hand shovel, and other miscellaneous things like a pencil, a measuring tape, a hammer and more.
The Workplace - Tool Time!
It’s supposed to rain for the next few days, so I really wanted to get this part done and cover it. Don’t know how much drying out will be accomplished but I’ve done my part.
Now I get all that chamber stuff you were talking about. What a great job, Chris. I am impressed. Judy