sizing help needed

[Forgeblast]

Hi all, I missed a page when I downloaded the instructions/guide. I poured a reinforced and thermal pad that is 49'' wide by 36 1/2'' deep.
I can get (by adding rebar and welding up a frame, and adding on to the pad(i left myself a lip around the pad) 10 more inches across and 9'' forward.
giveing me a grand total of 45 1/2'' deep by 59'' across.
My question(s) is
1. what size oven can i now build with the new dimensions.
2. is there a different type/shape oven that would work on my old pad?
3. any suggestions would be appreciated.
Thank you all in advance for all your help.
(sorry for all the smilies my 2 yo was "helping" me type)

[Faith In Virginia]

Re: sizing help needed

Is this what your missing? I may be wrong but it sounds like your small on your dimensions. With what you have stated I think the oven would be too small for any great use. But that is just from what you have stated.
Hope this helps

[azpizzanut]

Re: sizing help needed

Hi Forgeblast,

Can you post a few photos of what you've done so far? That will help us to come up with a solution to your challenges.

Cheers,

[Forgeblast]

Re: sizing help needed

Here are the pictures.
Picture one shows the oven base, with the reinforced and thermal slab.


Picture two shows the overall placement


one more for good luck

[Forgeblast]

Re: sizing help needed

STOVEMASTER - Semi-pre-cast brick ovens
wondering if something like this would fit. it seems to be similar in size, If I take the oven forward 9'' and then add on where the opening and chimney would be the oven would be around 45 x 45 and give me about 2025 square inches of cooking space.
Time to mess around with cardboard.

[azpizzanut]

Re: sizing help needed

Hi Forgeblast,

Thanks, the photos help to put things into perspective.

I think you have some major remodeling to do. It may be practical to consider deconstructing the hearth and starting over with the appropriate size while it is still early in the game. Yes, it's a pain ita, but worth the effort. It appears that you've done a nice job on the existing hearth slab so I'm not worried about how a larger rendition will turn out.

In regard to the Stovemaster oven. You are only seeing the finished dome, not the insulation which will add to the width and depth by possibly four inches on each side. Without seeing the completed oven I would venture to say he will use up all the space around it with insulation and enclosure.

My 36" Pompeii oven needed every bit of the 51" wide hearth slab. The external width of a 36" Pompeii oven averages roughly 44" before the addition of insulation. Three or four inches of insulation on each side will bring it up to roughly 52" wide.

I recommend that you re-do the calculation for the 2025 sq in cooking space. I'm thinking you can build a 31" diameter oven (internal dimensions) in the space available if the top slab is 45" x 59". But, it would be oriented all wrong. Where would you place the entrance and chimney? Take another look at the free Pompeii oven plans and see how the slab and oven are oriented. A fresh start will give you the opportunity to approach the build with fewer challenges.

Cheers,

[horrocks007]

Re: sizing help needed

The Giardino 60 will fit for sure.

[Forgeblast]

Re: sizing help needed

I wish I had the $$ for a precast. Just not happening this year, all on pay freezes.
Mick, do you know off hand the width and height of a barrel vault opening?
or a formula so that i can plan it out.

[Forgeblast]

Re: sizing help needed

Ty for the measurement work.
I was worried about the chunck of metal there also. I was planning on not having it there. I wont be doing two layers onthe floor because I have an insulated layer down already and will just be placing one layer of firebrick over it.
I was messing around with some cardboard templates and I might have found the perfect form.
drum rolll......a blue plastic barrel (the one that people use for rainwater collection) cut in half and in half again. (the reason is the lip that is on the top and bottom, this way you can keep the lip on the outside of where you are working.) I guess its time to just start doing some mock ups now. I really apprecaite the into on the opening size, if it does have a 10 inch with a 17'' finished height, what would the width be 16''?
When I did caluclated the 63% on the height of my mockup it was ~11'' so real close on.
MHA News - 2007 Meeting at Wildacres this also shows a barrel vault being constructed.

[horrocks007]

Re: sizing help needed

You also might want to check out roundboyovens.

Or.... What if you build a concrete hearth pad that is larger and sit it on top of your existing stand.

Another thought is to cut your fire brick to 3.5 inches instead of 4.5 and use fg insulating blanket with a 24 inch cooking floor. Might be better than a barrel vault.

[Forgeblast]

Re: sizing help needed

Thank you on the lintel part. I was planning on using an entry arch as the lintel, but are you saying that i do need stone/firebrick/angle iron to frame the opening on top of the arch?
" flames would more closely follow the pattern they do in a pompeii oven."
the ovens we have used though all the coals have been raked out and we just cooked in them, there wasnt a flame pattern, also when thinking of my wood stove, its square inside, there are no "cold spots" the heat radiates into the whole fire box. (I also read this article that talks about the differences in the ovens) Igloo round oven dome, rectangular Barrel domes, brick arches, vault shapes building circular brickwork.
Thank you again, I will be doing a whole lot of searching now for how others did their lintels. Many of the "turnkey" ones are cast, which really doesnt help when you looking to build one from bricks.
A couple of the stonebuilding books I have talk about home construction and using an arch for the lintels, I may need to do that in another project that I am working on.
Appreciate it.

[Forgeblast]

Re: sizing help needed

don't do anymore research--lmao. yeah you can over think it pretty good. I am going to try to get some firebrick and do some layouts. I tweeked my back today carrying bags of mortar to the house (I am putting field stone on it). I may have them deliver the bricks and mortar just to save my back a bit.

[Forgeblast]

Re: sizing help needed

Just doing a math check.
(bricks will be standard medium duty firebrick ~9x4x3)
36'' width of slab -9'' for firebricks (4+4+wiggle room)-3'' of insulation (i have a 1'' lip around the slab so i can add more insulation as needed), gives me an inner width of 22''

49'' lenght of slab -9'' for firebrick-3'' of insulation, gives me an inner lenght of 35''

Height stumping me would it be 13'' inner height? (22 width-9'' of firebrick=13''). or go up to ~17''?????just confused here.

Opening would be 12'' wide (inner width)+9'' of firebrick=21'' divided by 2=to center it I would need 7'' on each side.

Opening height would then be ~10'' to keep 63% but is that if the internal vault height is ~17''.

width of the opening would then be 4(firebrick)+6'' chimney pipe+4'' final arch=14''?????

(I will be adding a bluestone ledge to the front of the stove that is 16'' long which will partially hold the opening. )
Tyvm.

[Forgeblast]

Re: sizing help needed

Its the 49''. The oven will look like a loaf of bread.
I went to our local brick place and they said they only carry 9x4 1/2 x2 1/2 firebrick, along with 9x4 1/2x1'' thick firebrick(this is more the kind used for lining wood stoves).
and 50# of premix hightemp mortar 60.oo a bag.

[Forgeblast]

Re: sizing help needed

MHA News - 2007 Meeting at Wildacres
look about 7 pics down the barrel vault they are making is sideways with the opening in the side(just like my set up will be). Putting the entrance in the end would be easier but this way with it on the side I would be able to reach all parts of the stove....and it would work with what I have.