Brutal! Worth every effort!

[Karyn B]

This has been so tough but fun! I am posting my not so perfect work. But my columns are level! My arch transition bricks were very hard to place. The fact that Im not a mason prolly has something to do with it! Anyway have fun out there.

[Bauldy 2]

Looking good keep planing each stage use the knowledge on here

[UtahBeehiver]

These ovens are a labor of love. Congrats on completing the dome. You overcame a big case of the "dreaded droop" over the arch in good fashion.

[Karyn B]

Thank you. I did not know about the dreaded droop! I have a whole new appreciation for the precision and beauty of the builds I see here!

[UtahBeehiver]

What type of chimney are you looking at? If a brick chimney you may have to buttress the vent chamber walls, if a SS chimney you probably ok not buttressing. This is due to the flat arch there is a lot of outward pressure at the vertical vent chamber wall and the arch. SS chimneys are not near the weight of a brick chimney so hence less outward pressure.

[Karyn B]

Thank you for the advice. I am planning a double wall SS. I am also going to buttress the arch and soldier course per your recommendation. I am insulating with 3 inches of blanket but wondering if I should also cover with vermiculite? Your thoughts?

[UtahBeehiver]

3" in ceramic blanket is plenty good. As for vcrete, not necessary if you are good with how the base shape of the dome looks after the insulation is in place. If is good then you can wire lath or welded wire fabrics the insulation and stucco right to it. If not vcrete can be installed to give you the base shape you want. Then stucco. You do want to cure the oven "after" the insulation is on but "before" the stucco is placed.

[Karyn B]

Omg! Utah! You answered my question before I asked!!! Thank you! I was wondering about that. Actually we are enclosing in a "house" so should I pour dry vcrete around dome for extra insulation? And that was my next question about curing!!! Thank you so much!! You da bomb!

[UtahBeehiver]

If you are enclosing the oven then you really only need install the 3" of ceramic blanket, no need for vcrete/pcrete. That said, some builders have filled the structure with "dry" vermiculite or perlite after the structure is up for extra super insulation. There is a point of diminishing returns on this amount of insulation but v or p is relatively cheap compared to ceramic blanket. If you chose to do this make sure you leave an access point to add more as it settles. You can place halogen heat lamps in without ceramic blanket, gets you about 130-150 F once the blanket is on the charcoal, gets you about 200-220 then follow the FB cure guidance. You can cook something with the charcoal portion. Word of caution, this is where some builders get over zealous and heat too quick and hot, cracking their ovens. The turtle wins the race here.

[Karyn B]

Thank you Utah. I will go slow on the curing. I finished the vent opening today. Will install chimney and buttress next weekend.

[UtahBeehiver]

What size SS are you installing? The I am guessing on the opening based on pics and it appears to be about 4 x 9 or 10 which is 36-40 square inches. The opening should be at least the same are the ID area of the SS chimney pipe, A= pi x r squares, ie 3.14 x 3x3 for 6" Id pipe = 28.7 square inches, so opening good, 3.14 x 4 x 4 = 50.2 square inches for 8" ID pipe so opening too small. Just bringing to your attention. Typical recommendation 32-36 ID oven 6" ID chimney, greater than 36" 8" ID chimney

[Karyn B]

I finished the vent arch and left about a one inch reveal. Getting there!! Woohoo!!!!!

[Karyn B]

Oh Utah the vent opening is 4.5 x 9. You clearly are the engineer. I resort to pictures! . I am planning to install an 8" Duratech double wall 24" or 36". Not sure yet. My oven is a 42". Does ID mean internal dimension of oven?

[UtahBeehiver]

Yeah, retired engineer. So here's the potential issue. The 4.5 x 9 inch opening has an area of 40.5 square inches and the ID (internal diameter) of the 8" SS chimney has an area of 50.2" square inches which means there is a restriction of flow by the small area brick opening going into the larger area 8" chimney vent. In addition, rectangular openings are not as efficient as round openings. This could case in flow restriction to cause smoke to back up then out the front of the oven. Ugg, I know, but you need to a be aware of this, smoke will follow the path of least resistance. 8" is the correct size SS vent for a 42" ID oven. So you need to take about 1.5" out of the depth of the 3 arch bricks.

I also attached a copy of an anchor plate that you need for SS pipe. This one is for Selkirt so not quite that same as Duravent but you will get the idea, you need to get the dimensions of the Duravent anchor plate for your build.

[Karyn B]

Utah, does it help that my under arch opening is about 16 inches wide and then funnels up to the 4.5 x 9 opening? I made my arch like Ken524's build albeit not as pretty!