some help with starting to lay bricks for dome

[NattyB]

Greetings folks - a 'newbie' here and rather excited to finally be building our oven! The concrete counter top is complete we are now building the floor and ready to start laying bricks to make our dome - however would like some input here as whether the best plan is for the first row of bricks to start at the oven floor OR if the bricks should start right on the concrete base? (see photos option A or B) What is the best way and why?

[JRPizza]

Hey NattyB , welcome to the forum. It's a good thing you asked this question before proceeding, and the question makes me think you should likely do some more homework before proceeding.
You can build your dome on the floor or surrounding the floor, but if you build outside the floor the insulation under the floor must extend past the floor so the dome bricks are not sitting directly on concrete. This brings us back to the homework part of the discussion. If you have your floor laid and are wondering whether to build on top of or outside the floor, you are looking at a changing the inside diameter of your oven by about 9 inches! Stepping back, how big did you want your oven to be? Is the floor the exact size you wanted the ID or did you oversize it by 9" to accommodate the bricks sitting on the floor? It's possible you will need to build outside the floor to get the desired size, and if that is the case you will need to add insulation or suffer with an oven that does not retain heat properly.
Other than downloading a copy of the Forno Bravo oven plans (if you have not already) it would be helpful if you post some details of what you are wanting to accomplish in terms of a build and what steps you have taken to date.

[UtahBeehiver]

In addition to JRs comment. I am not sure if the dome bricks in the pics were show just for reference but the dome needs 4-4.5" thick not 2.5" thick and can be either a half header or half or full soldier. See attached. If you need to place the bricks on the outside of the floor then you will need to pour a 5 to 1 pcrete support ring around the floor perimeter to support and isolate the dome from the concrete hearth.

[NattyB]

Thank you for the comments/feedback - I do have a copy of the instructions however i find they are missing much detail - in any event the bricks were placed on the oven floor which is on the insulation and slab and we are within the 35.5" that the oven was to be so no deviation from the plans! thank you again.