half bricks for dome too much ?

[mikeyr]

I was reading the instructions for building this oven and noticed that it says when you split the bricks it leaves the dome a little thick but it will work.

Coming from another brand of pre-cast ovens and looking into building one of these within the next few months (I made a mistake when I bought the other oven 6 years ago, its too small and I want a bigger one in my new house), I was thinking that since I have to split the bricks anyway, why not make them 3" or some other size and just split them twice. Its a little bit more work but i think worth it in the end, to not have too much mass to heat up when you want a quick pizza.

My cooking is primarily pizza with 2-3 loaves of bread once a week. I do like my turkey cooked in the oven too but for that I have gotten used to have a small fire and not burning the bird so I am primarily a pizza guy.

And while thinking about cutting bricks, why not cut the floor bricks to fit INside the oven as I have read that is much better and the way the pre-casts do it anyway, that will be a lot more cutting but its just time anyway.

[Dutchoven]

Re: half bricks for dome too much ?

It becomes difficult as a do it yourselfer to build a stable dome as the bricks get thinner. The line of thrust on the dome has to remain in the center third of the thickness of the brick to be stable. It is definitely do-able though. As for cutting the floor inside the walls, it is a very good way of doing the job...much more cutting...but you already realize that
All the best!
Dutch

[Les]

Re: half bricks for dome too much ?

Mike,

My walls are built around the floor - It wasn't too bad to do. After I started mine, I realized that I probably could have gotten away with cutting the bricks in thirds. I see no reason why it wouldn't work. Less brick, mortar, weight, mass etc... Many positives.

Les...

[KiwiPete]

Re: half bricks for dome too much ?

There are quite a few people on here who have built ovens using 1/3 bricks, including myself.

There is no problem with that whatsoever: quicker heatup times (because you have less thermal mass). But also a bit less heat retention. I still happily cook big meals (turkeys etc) in mine without a problem.

I tried to compensate for the lower amount of thermal mass, by going overboard on insulation, which is always money well spent.

[james]

Re: half bricks for dome too much ?

Hey Mike,

I can guess the other oven that you bought.

My take is that is you feel confident getting the stability of the oven under control using 1/3 bricks, you will end up with an excellent oven for home use. As folks have pointed out, and experience shows, ovens in the 3" zone offer a nice balance of heat up time and heat retention. I don't think you would miss the last 1 1/2" of mass with a half brick.

On the flip side, if your bigger worry in construction and dome stability, then go for the half brick. It won't detract from your oven enjoyment.

My two cents.
James

[dmun]

Re: half bricks for dome too much ?

I probably have the thinnest oven of any hand built brick oven, with the bricks set on edge for a two and a quarter inch thickness. I'm not sure it's worth the extra effort to build a thin dome. It still takes a big fire to heat it, up, and let's face it: You're throwing logs into this thing. I think a little strength is a good thing in an oven dome.

[gjbingham]

Re: half bricks for dome too much ?

Good reply, Devil's advocate dmun. You're probably right. The speed of heating the oven is probably faster by perhaps 10 - 15 minutes max. I still like the idea of the postulate that it would be more efficient. Who knows, it may really be less stable not having the extra mass when each brick is missing the outer third of a normal half-cut-brick.

[mikeyr]

Re: half bricks for dome too much ?

Interesting point about the strength, I had not considered that one and I agree it probably is only 15 or so minutes more if you have a roaring fire going.

I am still in the "thinking and research" stage, I do know I am moving and I would like a bigger oven at my new place.

[james]

Re: half bricks for dome too much ?

Is it 15 minutes, or is it perhaps more? One of our competitors (we shouldn't use names) takes a solid 90 minutes to fully fire -- where the same size FB pre-made oven can be ready in 40-45 minutes.

Sorry to sound like a marketing guy there.
James

[70chevelle]

Re: half bricks for dome too much ?

Ok, this is a revelation of sorts. I hopfully will have my hearth poured this weekend or early next week, so I'll be buying my firebrick and starting my dome shortly. Since my oven is going to be relatively small, 30" diameter interior, should I have any worries about dome stability? My plan is FB board under, and 2" of blanket on top. Will I realize any detriment going to 1/3 bricks?

[Dutchoven]

Re: half bricks for dome too much ?

Chevelle
30 inch is pretty tight, what interior dome height are you considering? You might have to have a pretty agressive curve to the dome. Is there some reason you are planning an oven at 30 inches because although you can cook less in a larger oven you can't cook more in a small oven. Heat up time would not be very different if you went with a larger say 36" diameter oven.
Best
Dutch

[70chevelle]

Re: half bricks for dome too much ?

Necessity! It's all the room I have, and I'm going to have to work to make sure I can get a full 30". (or potentially go to a barrel vault) I'm not too concerned about a lot of food, only because I have a multitude of cooking vessels to use if this one gets filled! I plan on firing it for pizza's, one at a time, for get togethers, and family cooking. If I'm being honest with myself, once a week is going to be a lot of use, it's probably going to be more like twice a month. Anyway, to your question. I think my calc's came to a 17" interior dome height, with an 11" arch height at the opening.

You can see my progress on the thread I started http://www.fornobravo.com/forum/f6/f...html#post34203

(I started with a 36" square foundation. With some innovation, I increased the size to approx 48" x 52" with lintels & block. I want to pour my hearth inside the bricks for clean look, and I will lose approximately 12" of depth due to the fireplace chimney at the rear and cantilever the hearth approximately 8" in front for an approximate useable depth of about 48" useable. I figure I'll lose 4" a side for brick and another 2" for insulation, and then the thickness of the firebrick for the dome - 1/2 brick 4.5", 1/3 brick 3". 48-12-4.5 = 31.5" give or take. 1/3 bricks will give me 48-12-3 = 33")

[mikeyr]

Re: half bricks for dome too much ?

Well I am here getting ready to build because my existing oven is too small, so take that into consideration when you are getting to build yours at 30", that is what my oven currently is.