Under construction

[splatgirl]

Re: Under construction

Is there a reason why you want to use firebrick as your hearth insulation? Vermiculite/concrete is cheap, easy, efficient and proven.

[splatgirl]

Re: Under construction

FWIW, I've seen/cooked in a barrel vault (with vermicrete hearth insulation, again FWIW) and it made every bit as good a pizza as my igloo. I have not baked bread in the barrel vault but I can attest to the fact that my igloo style works great for that, so I don't think you can go wrong either way. What matters more than the shape and as much as the overall mass, is INSULATION.

[grega]

Re: Under construction

No reason to use them, just concidering options, after all mass is what stores heat for prolong cooking AFTER pizza, and yes the mass will take a bit longer to heat up but the time it creates for baking without fire seems to make sense. Several successful bakeries can't be wrong with generated radient heat for hours and hours. Hot air does rise,so the idea is not only keeping the heat in the floor and how much will REALLY be lost going out the bottom? Splatgirl, these are just ideas, this is my first oven, but I will NOT use fire brick as an insulator, I just want it right the first time. I make KILLER pizza on my stone in my oven at home +/- 500`,the only thing is not having wood fire taste, the wife is from Brooklyn and say's it's the best she's had in 30 years of being in Fl., I said your just saying that , she said NO REALLY.hehehe, silly wife loves GOOD pizza, so do I.

[dmun]

Re: Under construction

While you figure out how to get the plans from the Forno Bravo store, (it's really not hard), you might want to read the "sticky" postings at the top of the forum categories. They contain a lot of good information, including why round ovens are superior to rectangular ones for pizza use.

http://www.fornobravo.com/forum/f2/w...s-round-2.html
http://www.fornobravo.com/forum/f2/p...-oven-493.html

If you're planning to fire every day, and bake commercial quantities of bread, then the barrel vault may be a better choice, but for most home builders a round oven is the way to go.

how much will REALLY be lost going out the bottom?

You MUST insulate under your oven floor. You'll never get up to temperature, and keep it there without floor insulation. Two inches of refractory insulation board equal four inches of vermiculite concrete. Either will work well.

[grega]

Re: Under construction

Thanks, I DO plan to insulate the floor under the fire bricks, just haven't decided which way to go.

[splatgirl]

Re: Under construction

you could consider laying the hearth bricks on edge vs. flat to get more mass there.

Have you had a chance to browse the experiences of the folks here as far as heat retention? I think most of us would describe usable heat retention in our Pompeii style ovens on the order of three days, with day two being in the realm of bread baking temps.

Just wait...the difference between a 500 degree home oven pizza baked on a stone (which I was pretty dang good at before, too) and a WFO cooked pizza is astounding. Even when they're made with exactly the same ingredients and dough, they are not even remotely alike. So much more than just wood smoke, and SO worth the work of a WFO build!

You can't go wrong with following the instructions and advice available here, really.

[grega]

Re: Under construction

I agree, wood fire and the radient heat is the way to go. Thanks for the encouragement!
A friends parents had a wood fire oven when we were kids,though I had very few meals from it I remember it because of all the bread his mother use to make, we had sandwiches in the summer time that were so good!! They did own a local bakery and had wood fire oven there too! We spent alot of time there, they said we were about to eat them out of business!hehe We use to use the oven in his yard as cover when we played army? His mom use to tell us to get away from it so we didn't get burned, even though it was only warm near the chimney. we would climb all over it. Silly kids!
I have decided to go with a 4" vermicrete over my support slab, that should do it. Thanks for the advice and yes this website is very nice so far, I have learned a few things for sure. I can smell the pizza/bread and am getting pumped up to pour that support slab, maybe this weekend. Have a great weekend? maybe make a pizza or two?

[gdest]

Re: Under construction

All of the information I have read says to install the support slab ON TOP of the perlite concrete. I too have asked this question and have gotten the same reply not to do this, but after thinking about it, the support slab on top of the perlite concrete makes some sense when you consider the stored energy that will be needed for utilizing the oven for baking.

Any comments?

By the way I am still in the planning mode for my oven.

[grega]

Re: Under construction

gdest, I never once thought this was right, it just doesn't make sense to put a lite weight mix weather being an insulated slab or not UNDER what will weigh conciderable more. the heat will weaken the concrete slab over time and heat will be lost through the support slab. The vermicrete slab is an insulator and IT will storeheat and keep it from being lost. Just my two cents. Will someone confirm this please, Mr dmun? Thank you.

[dmun]

Re: Under construction

All of the information I have read says to install the support slab ON TOP of the perlite concrete. I too have asked this question and have gotten the same reply not to do this, but after thinking about it, the support slab on top of the perlite concrete makes some sense when you consider the stored energy that will be needed for utilizing the oven for baking.

Any comments?

A single layer of flat firebrick on the floor is more than enough mass for a home oven. The insulation goes between the floor and the support slab. More mass to heat up means that you will only get up to pizza temperatures with the greatest difficulty, and with a massive expenditure of firewood. A slab with the insulation underneath will be a huge heat sink. Sure, if you fire every day, it will hold heat from the day before, but most of us fire our ovens occasionally, from cold.

[dmun]

Re: Under construction

it just doesn't make sense to put a lite weight mix weather being an insulated slab or not UNDER what will weigh conciderable more. the heat will weaken the concrete slab over time and heat will be lost through the support slab. The vermicrete slab is an insulator and IT will storeheat and keep it from being lost.

The light weight insulation layer under the heavy oven is a proven technology. It works with my oven, it will work with your oven. If the stuff wasn't lightweight, it wouldn't be insulation. They build entire HOUSES on top of insulating foam: A one ton oven will do just fine.

[grega]

Re: Under construction

So, once and for all , the support slab first, the verm.slab on top of the support slab.

[grega]

Re: Under construction

gdest,
After all the advice on this site and teetering back and forth,I was talking to a friend of mind who has been in concrete work all of his life, houses, fireplaces, and even a few ovens go figure, he agrees with the idea that, especially here in Fl. and probably in your climate as well to put the vermic. slab ON TOP! It makes more sense to me now,duh, I just needed to be slapped I guess. ha! It will NOT take near as long to get up to temp. here in Fl. and the heat will stay around longer than I will. After a few pizzas, (and if I don't barf from being stuffed), a few loaves of bread when the oven cools to baking temp. I WILL put this together as stated. And dmun , splatgirl, thanks for your patients with me,I just want to get it right, and thanks to this website for keeping me/us from making a big mistake! G

[DrakeRemoray]

Re: Under construction

For the record, the round oven with the hearth laid flat can still give a ton of retained heat. I have an extra inch of mass in the dome (not in the floor) and I have baked as much as 30 lbs of bread after a pizza session. Most of the time, I am sitting around till 10PM waiting for the oven to cool off enough to put my bread in. I cannot forsee that any home user would want more mass (such as hearth bricks on their side). If you are selling commercially, then maybe, but for home use, never.

[grega]

Re: Under construction

Thirty lbs. of bread in that little oven, you must be up half the night.