How to build chimney and outer arch

[kbartman]

Re: How to build chimney and outer arch

1 and a half tons spread mostly over the entire footprint of the oven is nothing if you have good foundings and good support for the oven slab.

I have not posted anything about this subject on my build and been wondering if any is interested and would like to discuss it. I would be willing to post and explain my foundation footprint and supporting structure with pics as time permits on this thread if RichC and others would like and approve.

[RichC]

Re: How to build chimney and outer arch

By all means KB

[kbartman]

Re: How to build chimney and outer arch

Ok RichC ,
We will start at the very beginning, as I try not to be long winded and make it enjoyable. Here is text along with a picture I sent to my adult children last fall: Kids we decided to bring Lalane home to be with us, we felt so far away from her all the way at our house on Whitedove, Please visit her soon. Lalane is the long lost sister the older kids told their youngest sister about when she would not comply, they explained to her the value of listening to Dad about doing right, and eating her veggies: Hence the start of the pizza oven construction.

Most houses in Florida begin with block construction do to termites on top of a poured footer 16”x 8”x8” with two 5/8” rebar parallel on 8” centers…………. I felt this was more then adequate for the WFO ,heck a house can sit on it………………..although I did use ?” rebar thinking that was what I remembered of my construction experience and as stated in the FB plans. My first oops………. More to come I have been working nights need rest

[kbartman]

Re: How to build chimney and outer arch

RichC,
I try to make this short so I don't have your thread high jacked to long. Also I just stumble across the this thread it looks like it could be another wealth of info http://www.fornobravo.com/forum/f9/n...ion-15708.html

My supporting structure continued:
Rebar overlap of 24? is standard Florida code Rebar was used in and corners and in the middle of pool wall to help tie in the stand to existing structure.
After the footer was poured and set a knee wall was built up to storage area. The center inside the knee wall was backfilled and compacted the vapor barrier was laid the 6?x 6? steel wire mesh was added for strength of floor pour.
After the floor pour the first course of blocks were set. Concerned the rebar tie in was not enough below the floor I decide to add additional reinforcement in that first course of block Also I felt my rebar overlap was not up to code, so I drilled and epoxied to achieve overlap.
Then the additional courses were set to hearth level.
Stand dimensions for my 40?that became a 39?oven:
Footer overall outside 72? x 80?
Stand overall outside 64? x 72?

[kbartman]

Re: How to build chimney and outer arch

More pics: and looking foward to comments, questions and suggestions.

[RichC]

Re: How to build chimney and outer arch

That's a lot of reinforcement KB! Earthquake proof
I dug out and filled with about 150-200mm of hardcore, then put in a 150mm slab reinforced with 10mm bar and some mesh. I've then come up 4 courses of cavity blocks and shuttered and poured an arch in the front. I currently have the deck shuttered to pour the hearth slab(more correctly sub-slab I suppose)

[kbartman]

Re: How to build chimney and outer arch

No earth quakes in Florida. Hurricanes and sinkholes I know it?s a bit over kill, but I had some concerns after cutting the pool deck, I found quite a large void beneath the pool deck. Sure it was only settlement of the original installation. I don?t know if the news about the man being swallow up by the sink hole here in Florida made it to Ireland, but how tragic, I had night mares of my WFO also being swallowed up???I mainly thought if there was any addition settlement the It could cause issues for a full brick chimney.


Ok I will try to finish the explanation of my foundation and hearth and hopefully get the discussion going on how to build the brick chimney.
After blocks brought to hearth level, 1/2? Hardee board was laid and support was built to facilitate 3??concrete pour. Rebar was set on 8? x 8? centers and forms were built for monolithic arch. Rebar tied all together overlapped. I wish I would have extended pour over block courses. Pictures attached:

Will this support any size chimney?.................Inner arch will be complete soon...........Outer will be self-supporting with thermal break???????????? Where do we go from here?

[cobblerdave]

Re: How to build chimney and outer arch

Gudday KB
Forno oven stand is grossly over built to start with and yours in the true tradition is also! My own stand carries 170 odd firebricks and 200 odd house bricks in the dome and chimney.no worries.
Regards dave

[RichC]

Re: How to build chimney and outer arch

Looks excellent kb, perfect form work. My own arch bellied slightly in the front doorway so ill probably have to reshape part if it with a consaw. I assume its ok to pour the 3.5" slab with no airgap as it'll be we'll insulated from the actual hearth? My original build was from 'The Breadbuilders' book and the slab was part of the hearth so required an airgap. Now that I'm sitting a prebuilt dome and hearth on 4.5" vermicrete above the slab I suppose I don't need an airgap? Any thoughts in that?
Also, can I put fibre blanket down and pour the vermicrete onto it or would that make any sense?

Btw, I think I did actually hear about that guy that went down the sinkhole, it was quite a while ago wasn't it?

[kbartman]

Re: How to build chimney and outer arch

Looks excellent kb, perfect form work.

Btw, I think I did actually hear about that guy that went down the sinkhole, it was quite a while ago wasn't it?

Yes that was quite a while ago. Tragic

Hows the chimney build coming?

[RichC]

Re: How to build chimney and outer arch

Still working on deck so chimney is in planning phase

[kbartman]

Re: How to build chimney and outer arch

Are you going to incorparate a thermal break between the chimney and oven?

[RichC]

Re: How to build chimney and outer arch

By thermal break do you mean insulating layer? Hadn't thought about it. What's the pros and cons?

[GianniFocaccia]

Re: How to build chimney and outer arch

A thermal break is an engineered gap between the adjoining oven arch and the entryway arch. The purpose of this break is to minimize the contact area between the two structures in order to limit the amount of residual oven heat loss through the entryway once pizza oven temps have concluded.

[RichC]

Re: How to build chimney and outer arch

I hadnt considered it Gianni! Is it worth considering?
See attached image of the kit that I'm using. I'm thinking of using the chimney structure they provide which is 3 section thing with a cutout for the flue in the top section. How would you go about building a thermal break into that?
I've been consdiering building a brick chimney but I might just go ahead with the parts in the image. The sections in the image bond to the dome with refractory mortar? What do you think?

Thanks

Richard