51" Oven in France

[exipnos]

Hi all,

Let me first start by thanking Forno Bravo and the members here for a fantastic informational site. I've spent the last few days looking through the forum and I'm now about to embark on the construction.

Let me first start by introducing myself. While I was studying I use to work for almost 4 years as a "pizziolo".
While in the US for university studies I also worked for a short time for California Pizza Kitchen where I first got introduced to a wood fired pizza oven. I loved it. I now live and work in the south of France and was thinking of building a wood fired oven in my own garden.

This past weekend my father and I poured the foundation, built the walls and the reinforced concrete pad. My pad is 190*190 cm and I was thinking of maximizing my oven size to above the standard 42". I therefore leaning towards a 51" oven. The oven will be built out of standard brick split in half. The look will be similar to the on I found here on FB an also on Untitled Document.

Since the plans don't have this size I was wondering if there is any special considerations I have to look into before starting on the detailed plans?

Thank you for any help you can offer.

Regards,
Kosta

[krosskraft]

Re: 51" Oven in France

Are you going to open a restaurant in your back yard? The downside of a huge oven is that it takes more wood to heat up. Maybe you are used to a bigger oven having worked in a restaurant. I just want you to really think about it.

[Les]

Re: 51" Oven in France

Kosta,

If your hearth and foundation are built to withstand the weight, and you keep a descent dome arch - I do not envision a problem. That is a BIG oven. Myself, I never envisioned cooking a whole cow. Go for it!

Les...

[exipnos]

Re: 51" Oven in France

Thanks for the replies. Regarding the size I'm sure a 42" oven might be sufficient and I know that a size like that can produce a lot of Pizza in a short time. But having seen the circle on my large hearth I now think a bigger size might be in order. I might down size it to say around 47"-50". We love to entertain and sometimes it for quite a lot of people. Yes I'm used to the restaurant size and that experience also makes me want the bigger size because oven management could be tricky sometimes with many pizzas. I'm happy to work with 6 pizza at a time and then the extra space makes it easier.

The heath is built with a lot of rebar in place and I think it can withstand a direct hit with one of the bunker busting bombs

I'm struggling a bit regarding the dome shape. Having seen the FB ristrorante 120 and 130 specs it calls for a dome height of 22 and 23.5 in. Then when I read about the tuscan vs napolitan styles I see that this height is quite far from the napolitan height. Oven function will be primarily towards pizza so I'm not sure what to go for. I was thinking of maybe going for a slightly smaller 48" oven but keeping the dome height to under 20". Will that be doable?

[Les]

Re: 51" Oven in France

Kosta, You are getting outside of my box, but here are my thoughts. I built a 42 inch and my dome is pretty much 21 inch high. I was after the perfect semicircle. If you build it correctly, and you have the support on the sides, it should work. The forces that you are exerting in the horizontal axis has not been done here (to my knowledge). It's not my time or money - so I say go for it. 6 pizza's at a time, you are my new hero! (these were being cooked in 120 seconds or less, right?)

Les...

[exipnos]

Re: 51" Oven in France

The other point I'm struggling with is the "cosmetics" of the oven. I like the look of the spasso pizza oven (in my other message below) and would like to do something similar. But that style calls for a chimney that is not in the mouth of the oven but slightly recessed towards the middle.

I saw a construction at mha-net.org MHA News - 2006 Meeting - Backyard Oven with Peter Moore towards the bottom that shows details of the idea. Any idea how big the smoke channel needs to be? Any pitfalls?

Regards,
Kosta

[exipnos]

Re: 51" Oven in France

6 pizza's at a time, you are my new hero! (these were being cooked in 120 seconds or less, right?)

Les...

Thanks, with 6 pizzas you have to hustle both to get them ready fast before the stick to the the bench and you have to work fast in the oven. I don't actually remember if it was 120 sec but somewhere close to that Okay 6 pizzas at a time in only really necessary in a commercial setting and I rather just deal with maybe 3-4 at home

[Justin]

Re: 51" Oven in France

Kosta, my pad is 1.9m x 1.7m, and by my calculations i can only fit up to a max 42" internal diameter oven on that slab, while i am building mine to be about 40" (1m). remember you need to allow for 2x the: brick width, insulation, and final render. It adds up! Please triple check these figures before going ahead otherwise you may get a suprise when theres no room for insualtion.
Also if each pizza takes 2-3 minutes you can definately cook a whole heap of pizza in a short time even if youre doing 2 pizzas at a time. 10 Pizzas in 15 minutes.. do you really need more than that? Anyways, just food for thought, not trying to discourage you. To be honest i would love to see a 50" oven!

[exipnos]

Re: 51" Oven in France

Hi again,

Justin - I think my calculations for the dome was correct and I could fit the dome circle plus the insulation into my pad. But I now realize that I did not really take into consideration the vent/oven landing space. After drawing up the 51" circle I now see that it does not leave enough space for that. Thank you for pointing that out

I have now downsized my oven to a 120cm or 47" internal cooking surface.

Yesterday my father and I started by putting down 10cm AAC block as the insulation under the oven. We then proceeded to put down the 84 or so full size bricks as the cooking floor. The brick dimensions here are 11m by 22 cm by 7cm thickness. It was harder then I thought! The bricks are not exactly the same dimensions and there is sometime a small variance in either dimension.

Even though I was planning on just using sand as the base (I did not search for fireclay) and special refractory mortar (good upto 1200 degree Celsius) for the dome. In the heat of the moment I somehow forgot all my plans and mixed and used a sand/mortar mixture. The cooking floor ended up mostly even but in some spots to uneven for my liking. I have not checked this morning but I believe the bricks are now mortared in and cant not be taken out. I now have two ways to proceed. First choice is to grind down the uneven parts. Not sure exactly how to do that? Sanding it down or what tool?

Another option is that my supply store had special refractory tile 30cm by 30 cm. I was going to use that initially but thought the thickness of 3cm was to little. So option number two would be to install this large tile on top of my somewhat uneven floor surface. But that worries me that I would then have to much thermal mass in the floor. Total thickness will then be 10cm or about 4".

Is that to much thermal mass?

Today we will start on the dome construction. Before starting I'll play around with the dome height but I hope to stay as close to 20in as possible. Wish me luck I think I need it.

Cheers,

Kosta

[Justin]

Re: 51" Oven in France

Thats some bad news Kosta. how uneven is it? do you have a photo? im sure some people on here have come across this problem before and have some good advice. I'd be inclined to try grinding it down because as you say otherwise you will probably have too much thermal mass and it could be v.hard laying tiles over uneven brick. in any case goodluck!

[Frances]

Re: 51" Oven in France

I don't know what others think, but if the floor thickness is the same as the dome thickness, it should be ok... could even be an advantage.

With a big dome you'll be looking at a relatively long heat up time anyway, and I would think that 10 cm doesn't constitute a heat sink. But I may be entirely wrong here, so wait until you have some more opinions...

[dmun]

Re: 51" Oven in France

It's ok to grind off some high spots but don't go crazy and try to abrasive smooth the whole floor: the exterior of the brick is considerably harder than the interior, you want your floor to last.

[exipnos]

Re: 51" Oven in France

Hi again,

Here are some shots from today's progress. Lost a half day in thinking about dome shape, preparation and tool creation. I created a cutout of my dome shape. I decided to go for 20" height or 50cm exact.

Then my father and I started laying the first bricks. Using the cutout the first bricks went on all right following the curve. But then my father decided that he knows better and that he can eye the placement. Over a quarter of the circle is now off about 1cm from the curve. Oh well I hope it will be okay anyway.

Pictures attached. Bricks follow the curve very closely but on the picture is looks that there is quite a few gaps. The bricks edges are sometimes not straight and that shows in the picture. I hope its good enought.

The floor surface show that there are a few small gaps where again due to the shape of brick they don't touch. Is it a good idea to fill the gap? With mortar?

Thanks for you time.

By the way is there a way to change the title of the thread from 51 to 47" for accuracy?

[dmun]

Re: 51" Oven in France

The floor surface show that there are a few small gaps where again due to the shape of brick they don't touch. Is it a good idea to fill the gap?

An excellent material for filling those pesky floor gaps is wood ash. Leave them be. You may want to temporarily cover the floor with a cardboard cutout to keep your floor clean as you work on the dome.

[Les]

Re: 51" Oven in France

First choice is to grind down the uneven parts. Not sure exactly how to do that? Sanding it down or what tool?

Kosta,

I used a belt sander to take off the edges - it would take quite a lot of work to do the whole floor. You just want to get it to where you don't catch the edge of your peel.

Les...