Author Topic: Concrete dome  (Read 1252 times)

0 Members and 1 Guest are viewing this topic.

Offline Paulo78

  • Registered User
  • Posts: 7
  • Location: Cyprus
  • I Love Pizza!
Concrete dome
« on: November 09, 2013, 01:03:47 PM »
Hi,

I am in the process of buying a new wood fire oven... I found one which has the dome made out of concrete.
As I looked closer there are 2 layer of concrete and in between there is some insulating cotton/foam....

Now I am bit worried that it will not proform  as well as the the brick domes.....


Does anybody can give me some pointers....

Best regards,
Paulo


Offline Paulo78

  • Registered User
  • Posts: 7
  • Location: Cyprus
  • I Love Pizza!
Re: Concrete dome
« Reply #1 on: November 11, 2013, 10:43:17 AM »
Nobody...any suggestions??

Is brick better ? Or do they both perform the same.... ?

Online TXCraig1

  • Registered User
  • Posts: 11616
  • Location: Houston, TX
Re: Concrete dome
« Reply #2 on: November 11, 2013, 11:21:00 AM »
It's not that simple.

I think you will get some feedback if you post the name of the oven or, even better, the name and some detailed pictures.
I love pigs. They convert vegetables into bacon.

Offline stonecutter

  • Registered User
  • Posts: 492
  • Location: SC
    • Old World Stone & Garden
Re: Concrete dome
« Reply #3 on: November 11, 2013, 11:50:07 AM »
Hi,

I am in the process of buying a new wood fire oven... I found one which has the dome made out of concrete.
As I looked closer there are 2 layer of concrete and in between there is some insulating cotton/foam....

Now I am bit worried that it will not proform  as well as the the brick domes.....


Does anybody can give me some pointers....

Best regards,
Paulo
How  sure are you that it is concrete and not a refractory castable?   Cotton/foam insulation?  I doubt that too...cotton would burn and foam would melt.   Most likely ceramic or mineral wool....not sure about the what the ' foam '  could be.   Pictures would sure help....lots of bad products out there.

There are a ton of variables as far as what performs better..brick vs cast.  The advantage a brick dome has,  that being built from unit masonry,  cracking in the joints won't weaken the structure like a crack in the middle of a cast panel.   Good cast domes have seams to account for expansion and contraction, but that doesn't always stop a panel from cracking....a lot depends on the mix design, how it is used, etc,etc.  A brick dome has more flexibility to movement than a cast dome, in relative terms. 
http://oldworldstoneandgarden.com/

Look at a stone cutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred-and-first blow it will split in two, and I know it was not the last blow that did it, but all that had gone before.
Jacob August Riis

Offline bbqchuck

  • Supporting Member
  • *
  • Posts: 381
  • Location: SoCal
Re: Concrete dome
« Reply #4 on: November 11, 2013, 12:55:22 PM »
I believe regular concrete would be unsuitable with the high temps associated with Neapolitan baking.

Offline stonecutter

  • Registered User
  • Posts: 492
  • Location: SC
    • Old World Stone & Garden
Re: Concrete dome
« Reply #5 on: November 11, 2013, 01:15:12 PM »
I believe regular concrete would be unsuitable with the high temps associated with Neapolitan baking.

It wouldn't be suitable for a fire pit, never mind Neo baking.

 Portland is not a refractory material...that's why I'm questioning what the dome is actually made from.  If this one is made out of concrete ( opc, sand and aggregate) , then no need to look any further...it is junk and not worth bothering with.
http://oldworldstoneandgarden.com/

Look at a stone cutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred-and-first blow it will split in two, and I know it was not the last blow that did it, but all that had gone before.
Jacob August Riis

Offline bbqchuck

  • Supporting Member
  • *
  • Posts: 381
  • Location: SoCal
Re: Concrete dome
« Reply #6 on: November 11, 2013, 01:43:57 PM »
It wouldn't be suitable for a fire pit, never mind Neo baking.   ....

 

 :-D

Ya just never know what people will do.

Offline misterschu

  • Registered User
  • Posts: 197
Re: Concrete dome
« Reply #7 on: November 11, 2013, 01:50:37 PM »
Seems like Paulo's first language is not English.  I think pictures are necessary.  Ceramic wool is not easy to describe if you don't know what it is.  And to a layperson (not bricklayer  :-D) cement vs concrete is a  trivial distinction.  I have a self-built refractory cement oven and people ask me about my "Cement oven" or "concrete oven" interchangeably.

Offline Paulo78

  • Registered User
  • Posts: 7
  • Location: Cyprus
  • I Love Pizza!
Re: Concrete dome
« Reply #8 on: November 12, 2013, 06:56:39 AM »
Hi,

First thank you for the help everybody.... I am a noob in this subject so any help is appreciated.

Ok, I went to the seller again to take some pictures... He told me that is a special concrete for high heat applications. The wool is like misterchu said ceramic wool which is for the heat insulation on top of that they put a wire net and a second layer of concrete....

I asked him about cracks and he told me that he has the same oven in his house for over ten years and there are cracks but they are very small and do not become bigger 2-2.5mm.. He said this cracks are expansions cracks and will not affect temperature or lifetime of the oven....

Well never their less I would like you guys opinion... As sales people can say a lot...

So here the pictures (sorry some picture are upside down just realised after upload)
« Last Edit: November 12, 2013, 07:07:19 AM by Paulo78 »

Offline Tscarborough

  • Lifetime Member
  • Global Moderator
  • *
  • Posts: 3275
  • Location: Austin, TX
    • Pizza Anarchy
Re: Concrete dome
« Reply #9 on: November 12, 2013, 08:10:54 AM »
Technically, anything with a binder and graded aggregates is concrete, refractory or not.  That oven looks fine but ask him if there is any insulation under the floor, as it looks like there is not.


Offline stonecutter

  • Registered User
  • Posts: 492
  • Location: SC
    • Old World Stone & Garden
Re: Concrete dome
« Reply #10 on: November 12, 2013, 08:30:43 AM »
.......... And to a layperson (not bricklayer  :-D) cement vs concrete is a  trivial distinction.

Maybe so, but it is better to understand the differences in terms if you want to get a clear answer, and gain an understanding of a thing..




http://oldworldstoneandgarden.com/

Look at a stone cutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred-and-first blow it will split in two, and I know it was not the last blow that did it, but all that had gone before.
Jacob August Riis

Offline stonecutter

  • Registered User
  • Posts: 492
  • Location: SC
    • Old World Stone & Garden
Re: Concrete dome
« Reply #11 on: November 12, 2013, 08:32:49 AM »
The casting on the oven looks nicely done.  Personally, I don't like the mortar joints in the floor, and the oven opening looks huge in the picture.
http://oldworldstoneandgarden.com/

Look at a stone cutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred-and-first blow it will split in two, and I know it was not the last blow that did it, but all that had gone before.
Jacob August Riis

Online TXCraig1

  • Registered User
  • Posts: 11616
  • Location: Houston, TX
Re: Concrete dome
« Reply #12 on: November 12, 2013, 11:38:35 AM »
Correct me if I'm wrong, but exposed ceramic fiber insulation is a health problem, is it not?
I love pigs. They convert vegetables into bacon.

Offline stonecutter

  • Registered User
  • Posts: 492
  • Location: SC
    • Old World Stone & Garden
Re: Concrete dome
« Reply #13 on: November 12, 2013, 12:18:23 PM »
It wouldn't be a good idea for a  pizza topping, no.


 There are  a couple brands of ceramic rigidizers out there, or you can make a slurry of fireclay/portland and paint it on the exposed fibers.
http://oldworldstoneandgarden.com/

Look at a stone cutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred-and-first blow it will split in two, and I know it was not the last blow that did it, but all that had gone before.
Jacob August Riis

Offline Paulo78

  • Registered User
  • Posts: 7
  • Location: Cyprus
  • I Love Pizza!
Re: Concrete dome
« Reply #14 on: November 13, 2013, 02:33:24 AM »
Hi,

Yes, this are the two things which bother me too....the exposed fiber and the groud between the floor tiles.

The idea with the slurry is very good... I guess I could do that....

With the floor I could set a new layer of bricks on top of this one.... Without groud an then have the dome fixed on top of the new layer.... (Would this work??)
The only issue is that I would be already paying 1100 US$ for this oven if I start now adding stuff it probably blows my budget.
« Last Edit: November 13, 2013, 02:39:24 AM by Paulo78 »

Offline stonecutter

  • Registered User
  • Posts: 492
  • Location: SC
    • Old World Stone & Garden
Re: Concrete dome
« Reply #15 on: November 13, 2013, 08:13:00 AM »
You can build your own oven for less and it would perform better,  especially so if that oven is lacking floor insulation.
« Last Edit: November 13, 2013, 08:18:51 AM by stonecutter »
http://oldworldstoneandgarden.com/

Look at a stone cutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred-and-first blow it will split in two, and I know it was not the last blow that did it, but all that had gone before.
Jacob August Riis

Offline Paulo78

  • Registered User
  • Posts: 7
  • Location: Cyprus
  • I Love Pizza!
Re: Concrete dome
« Reply #16 on: November 13, 2013, 09:17:02 AM »
Hmm... I am seriously thinking about it.... Any books/manuals you suggest ?

Offline stonecutter

  • Registered User
  • Posts: 492
  • Location: SC
    • Old World Stone & Garden
Re: Concrete dome
« Reply #17 on: November 13, 2013, 09:53:36 AM »
Visit forno bravo, create an account (free)...download the free oven plans, then consult the board to clarify certain parts of the plans.  It is a helpful forum,  almost all of the people that built ovens from the plans have never laid a brick in their life.  And while the Pompeii oven may not be the greatest design or a true pizza oven,  it is a forgiving oven to build.

http://www.fornobravo.com/forum/
http://oldworldstoneandgarden.com/

Look at a stone cutter hammering away at his rock, perhaps a hundred times without as much as a crack showing in it. Yet at the hundred-and-first blow it will split in two, and I know it was not the last blow that did it, but all that had gone before.
Jacob August Riis

Offline Paulo78

  • Registered User
  • Posts: 7
  • Location: Cyprus
  • I Love Pizza!
Re: Concrete dome
« Reply #18 on: November 13, 2013, 12:16:27 PM »
Thank you Stonecutter you have been very helpfull,

Just a question regarding my idea of putting an extra layer of bricks below the dome, would this also create a insulating factor? Or does it need special material as heart insulator?

I am asking just to understand if I could fix the grout and heart insulation problem with this idea.

 

Offline misterschu

  • Registered User
  • Posts: 197
Re: Concrete dome
« Reply #19 on: November 13, 2013, 03:35:12 PM »
Adding bricks to the hearth and dome adds thermal mass.  Insulation is used outside of the thermal mass to help it hold heat for longer.   Insulation is usually a low density material (like the ceramic wool, or perlite-cement mixes often mentioned of here) and would be placed below the hearth and around the dome.


 

pizzapan