42” Pompeii in San Felipe, MX

[modified9v]

Thanks JR... the pics are super helpful. Curious, how wide did you make your arch form? Looks like about 6”??? Another question... I was shooting for an arch height of 12.5”. If I use full bricks touching edges it makes the arch 5/8” taller. Do you think that would cause performance issues? I like the idea of using the full 2 1/2” bricks but if it won’t draft correctly I cut 5/8” off the bottom brick.

[JRPizza]

I can't remember how wide I made the arch forms, but 6" sounds about right. It needs to be narrow enough to keep the bottom arch bricks parallel, and wide enough to support the bricks near the top of the arch and keep them from tipping. This assumes of course you cut the inner and outer form boards the same size and attach them in the proper alignment. As far as height goes, I believe the "ideal" ratio is 63%, where the FB plans try (I believe) to go with standard sizes. Their recommendation of 12.5" for a 42" oven is closer to 59.5% so adding a little height should not hurt anything. I think you could go up to around 13 1/4 and barely exceed 63%.

[modified9v]

Thanks for the tips and info on the arch opening percentage. Math was never my strong suit. Also, hope to get the arch form built today. I have everything I need to get started now, so no excuses (other than the heat and humidity). I’ll see if I can get some pics of my creation this evening. All plans on working on this project got derailed yesterday. LOL

Mikie V.

[roroman]

hi, is there a recomended percentage of how wide the opening should be, I am trying to build a 31" internal diam. but unsure of how wide the opening should be? my height is proyected to be 10" heigh, any opinion on this. thanks

[modified9v]

roroman 10” sounds close for a 31” hemispherical oven... the calculation is 63%. Dome height is a factor as well

[UtahBeehiver]

Width is more flexible than height, 10" height will be fine. FB ovens use a 19" width for a high dome "36" oven.

[modified9v]

OK... I think I have finally got this. Been way too many distractions in my life (Too busy for a retired guy). Attached is what I believe will get me over the arch (HUMP). At about 44 degrees it looks like I will clear it. I have drawn it out on the Top Dead Center brick. Having the tapered arch in this location will give me a nice 2 1/2” of exposed arch to work with to tie in the flue with a heat break. Arch dimensions are 20” by 13 1/4”

Does anyone see a problem with this before I take it out to the stand and start putting things together???

Thank you all for taking the time to take a peak,
Mikie V.

[UtahBeehiver]

It does not really matter on the exact degree rather that the top slope of the brick matches the same angle as the center line of the IT. So once you have the TDC cut then you work right and left of the TDC. For example, looking from the inside of the dome outward. The next brick right of TDC, the left side of the next brick will have the same angle as the right side of the TDC. The right side of the same brick will be defined by the IT, etc, etc. Then the opposite is done for bricks for bricks left of TDC. All the bricks are slightly different and left of TDC will not work for right of TDC. Do not cut them all the same as the TDC.

[modified9v]

Ahhhh, OK... pretty sure I’m following you. Basically every brick, although they may have the same angle, will not work from side to side? I see that I will have to work them one at a time to get a sweet fit... I suspect the same will be true with each dome brick that intersects the arch???

The thing that has had be stumped is how far in do I need to be to make that dome brick (the one I drew on that TDC arch brick) so it will make complete contact with the TDC arch brick. In other words, if I were to move that TDC brick further away from the center of the dome the IT would not reach it and I wouldn’t find out until it was too late and I’d have a mess on my hands. From what I can tell, by the time I reach that TDC the dome will not have come in too far to leave me with no where to place that dome brick. I hope I’m making sense with this. I clamped a dome brick to the IT and simulated that dome... that is how I came up with thinking I’m ok with the position of the arch form/template.

Does that make sense? If so, do you think I’m gonna make it with where I have it positioned now. Man, once I get this I think I will be off to the races. I’m probably making this wayyyy more complicated than it is and once past this hurdle I will laugh about it. I just don’t wanna screw this part up... I feel it is the crux.

Thanks, Mikie V.

[modified9v]

Probably should have taken the day off from working on this project. Ya ever feel like nothing is going right? Are you treading water with no end in sight? Can’t sleep?

This thing with the arch is obviously kicking my behind, but that ain’t all. My base. Ughhhh!!!! Let me back up a little... We started this whole project with a perimeter wall. I hired a local contractor to do this. Keep in mind I live in Mexico. It was a big project. I had told the contractor about the pizza oven and showed him the plans. He offered to build the base and pour the slab that goes under the floor. I told him use super strong concrete, a ton of rebar and make it flat... I must have mentioned the “FLAT” thing a gazillion times. Now I know they used a bunch of rebar cuz I watched them lay it out, Shoot, the oven could rest on the steel alone. But the concrete is crap. And, it is anything but level. I didn’t realize just how bad it was until I ran a big long straight edge across it six ways from Sunday.

I had mentioned that the slab was off in a previous post when I asked if stucco could be used to level it out. There was a suggestion for fireclay and sand. This thing is so far out that I’d use up too much fireclay. Keep in mind I have to cross the border twice and it’s an all day trip to get more. Hence stucco. Everything here is stucco or plaster. Next character to enter the mix is my carpenter. While everything else is going on around here, changing windows (bigger and energy efficient ), new counters, insulation, a/c ( mini-splits) being moved or installed, solar work... oh, and I had to add another sink in the kitchen... yadda yadda... anyway I hired a carpenter to build all brand new cabinets in the kitchen and bar area. He is an amazing guy (he has taken over my garage). He had a solution to the hearth slab being out of whack. His idea was to level one edge to start with a 1” strip of concrete laid on top of the slab on one edge... then, shoot a level to the other side and do the same thing... had to knock down some big high spots (used a sharp axe with little taps. Came right off. The idea was if we had 2 edges that were level to one another we could pour a loose mix in between and scrett it with the straight edge... here we go. I’m likin’ it...

I have attached a picture of one of the very custom kitchen cabinets my carpenter is building for me. Super cool.

We mix 1 part Portland to 3 part sand, just add water they said... LOL. It didn’t stick. It was a crumbling mess. Not sure what to do next, but my carpenter said “I have idea”... he will tell me about it tomorrow. Ahahahaha... maybe someone else has a better idea. Gotta love doing work in Mexico where nothing is square, level or plumb.

Sorry for the rant... tequila time,
Mikie V.

[JRPizza]

I think you have it. I might have been a little closer to the center of the oven with my arch - see pic below - it's a better view than the one I previously attached. If you are too far out from oven center you will have a point where the dome slope and oven ID intersect very low on the TDC brick, and if you are too far inboard the point will be near the top of the brick. Mine came out just below the centerline of the brick. I "think" it is good to shoot for an intersection point about 2" up to match the thickness of a brick laid on it's side.

[modified9v]

JR, the pic is exactly what I needed to see. Between you and Utah you have given me what I need. Really glad you took a lot of pics. I need to take a lesson.

[modified9v]

Well, major setback today. My carpenter and I formed the base to lay a coat of stucco to level and true the base so I can start building. We got it all formed up and it was really, really good. We decided to score the concerte base to give the stucco a better chance to adhere. My contractor climbed up on the base and it started cracking as soon as he started to score it. He was using a wire wheel on an angle grinder... not a very aggressive wire wheel. The concrete was coming off way too easy. As a matter of fact you could score it with a finger nail. Concrete was nooooo gooooood. Contacted the contractor and he came and looked at it. He said it needed torn out and completely replaced and I agreed. This time my carpenter and I will frame up the form. Ughhhh, glad we made the decision to redo it now before we got too far along.


Question, how long do I need to let the bas cure before I begin the build?

I tried to upload a picture but pics won’t upload right now for some reason.

Thanks for following along, Mikie V.

[Gulf]

Try and resize the pics and see it they will upload. It will help for me to understand the thickness that you are pouring to level the stand or hearth? I'm also not sure exactly what cement you are using? You mentioned above about a stucco mix and then a portland and sand recipe?

[JRPizza]

Did your contractor give any theories about why the concrete didn't cure properly? Is he covering the cost of the tear down and re-pour?
If you build your forms right and finish off the surface after the pour you really should not have to do a secondary operation to level/true the hearth. You didn't post any pics of the forms prior to pouring, but lots of advice here on how much rebar, how thick to make the slab, and how to tie into your base. Now is the time to correct any design deficiencies and make any improvements you want in size/height of your slab. Make lemonade out of lemons.