36" Pompeii in Chicago

[Chef_Marsh]

Long weekend, so got quite a bit done. Layed out floor and soldiers. Then added first course and mocked up the arch support. Having a lot of fun with the brick work. Making the homebrew was easy and getting used to making the right consistency.

[Chef_Marsh]

Forgot to post pics!

[Chef_Marsh]

Next, I did the 2nd course. Then did the inner arch, then the 3rd course. I decided on a 1" reveal. I am trying to emulate banhxeo76 inner arch and IT tool. I think it turned out okay. Not as pretty. I realized quickly that I would have to adjust the IT tool because the hinge was not close enough to the center. The first 2 courses were okay, but I would have to adjust the remaining courses.

[UtahBeehiver]

Just be aware that with this IT setup, the face of the bricks are not perpendicular to the center of the dome. the error is cumulative in each course so by time you hit the upper courses the internal face of the brick may be way out of wack. The inverted V is starting to show on the latest courses, it can be eliminated by a small bevel on the front top side of the two jointing bricks. See JR Pizza build.

[Chef_Marsh]

Thank you Russell. I appreciate the feedback. I will adjust my IT with each course to ensure it is hitting the mark.
Also, my inner arch is too far out which is going to cause my dome to be out of round eventually. Do you have any suggestions on how to fix this issue? I couldn't sleep last night thinking about how I am going to make this thing work. Any help would be appreciated.

[UtahBeehiver]

Due to the inner arch not being a tapered inner arch, the shape will go oblong up to the top of the arch. then you will "gradually" have to bring back into round through several courses and bricks per each course by adjusting the IT around the front portion of each course and brick. Just take you time

[GreenViews]

Reading your comments got me thinking about IT designs for low dome builds again. While I used another design in my build, I was thinking about the geometry of your IT. If the length of your IT beyond the hinge matches the distance from the hinge to the desired top of your dome, I would think that you could keep the angle at the top of the IT constant as well as the top section length and vary only the distance from the hinge on the IT to the center of oven. This wouldn't be able to incorporate a complex shape like a 3 centered arch, but should be able to account for a simpler low dome shape. Personally, I'd just keep referring back to your dome template to make adjustments. Regarding your issue of the inner arch being done and not meeting your dome: I have no experience, but architectural design of arch stability would seem to suggest your oven would be stable enough if each cross section creates a stable arch design, so the elongation shouldn't create a weak structure unless you create inverse curves (convex to concave) to meet up with the inner arch. An egg is oval shaped and a very strong shape after all. Nearly as strong as a sphere. Glad you are making good progress now! Look forward to seeing it progress further!

[artistadimattoni]

Thanks, Ricky, for the information. I checked with a concrete industry guy who told me to put in the rebar, but I don't think he knows the context of the high heat conditions. The two patches are not under the pizza oven, but out near the edges. They are not any closer than the rebar in the lower structural layer in relation to the oven. Is this just wishful thinking? I will be adding a final layer of concrete or stone to the hearth for the finish layer around the dome and entrance. Has anyone else had this issue?

[UtahBeehiver]

On a different topic, are you going to do a tapered inner arch? Now is the time, base on the pics to consider it. It makes tying the dome into the arch much easier and cleaner. Do a search a tapered inner arch if you are unfamiliar with the concept.

[Chef_Marsh]

Thanks GreenViews for your comments! I guess I would then be worried about the correct dome height-to-arch height ratio as my inner arch is already 12 inches. I was aiming for 18" dome height. I have moved my hinge as close to center as possible now, will keep adjusting as I go.
Thanks again Russell for your continued support! I have already set my inner arch without a taper. I was going to wedge in blocks until I reach the top. I do see the worth of the taper, but ultimately seemed easier for me to not taper. Honestly feeling a bit frustrated and anxious at this point given my current issues.

[GreenViews]

Yeah, it's pretty simple really... just be sure that the brick face is perpendicular or points toward the true center of your arch. If you have any doubt, make a template of your exact desired dome arch and verify each course is pretty much where it needs to be. That is you can set your IT according to your dome template for each course. I put radial lines on my dome template pointing toward my dome arch's true center. The dome arch true center is the point from where you would draw a semi-circle to create the shape of your dome profile. This will be below the floor level on a low dome build. I think I am repeating what you already know, but saying just in case helpful. Look forward to watching your build progress.

Oh, Wait!! You say you are going for an 18" dome height with a 36" diameter! in that case your build is designed to be a normal Tuscan style semi-circle dome, I believe you don't need a complex IT design if you can have your pivot very close to the oven floor since the true center of your oven dome curve in that case is the exact center of your oven floor at floor level. Which is I guess why you ended up putting the hinge closest to your center as possible. I'm sorry, I guess I misunderstood and thought you were doing a low dome build.

Regarding your inner arch height to dome height: A 12" inner arch height and a 18" dome height gives a 67% door to dome height ratio, which is within the normal 63% to 68% ratio and you are using the recommended dimensions in the FB guilde v2.0, so that should be good FYI, I think it was JR Pizza? who shared with me this primary source material validating this door to dome ratio. (linked below).

[Chef_Marsh]

Thanks for the insights GreenViews! Making some progress with 4th, 5th and 6th courses. And then 7th and 8th. Not sure I am counting the courses correctly, but moving along none the less. I still have a bit a tear drop at this point and slowing bringing that in with each course now that I tied into the arch completely.

[Chef_Marsh]

At this point, I realized a sand dome would be easiest for me, even though I was able to get the first bricks of course 9 to stay in place. Built a stand and raised floor out of plywood and left over 2x6s from the hearth pour, then filled with sand. I just used leveling sand I had left over.

[Chef_Marsh]

Closing in now! Finished the last few courses and then the keystone! The keystone cutting was a challenge, but ultimately made it fit with many, many trips to the saw. And I still have all my fingers! Feels really good to finish with the dome!
I wasn't really sure how long to leave the sand dome in place. If anyone has done one, please let me know.

[BeanAnimal]

Closing in now! Finished the last few courses and then the keystone! The keystone cutting was a challenge, but ultimately made it fit with many, many trips to the saw. And I still have all my fingers! Feels really good to finish with the dome!
I wasn't really sure how long to leave the sand dome in place. If anyone has done one, please let me know.

Nice job -

The dome is fully self supporting and all of the courses are in compression (360 arch, if you will). Get the sand out of there and get your mortar joints cleaned up and pointed.