Three Questions

[Microheli]

With the help of my 81 year young dad and the blessing of my beautiful wife, I have decided to extend my patio and build my first of many pizza ovens. I say many because if any of my friends like my creation; I promise to help and educate them in building there own pizza ovens.

We have finished the Oven Stand part of the oven using concrete bocks and rebar, dimensions are 4 x 4.

The Oven Stand consists of the following:
1. Concrete slab of ready mix concrete with ½ inch rebar frame for support placed on a supported sheet of cement board, approximately 3.5”.
2. One coat of Perlite mixed with Portland cement approximately 1” .
3. One layer of fire bricks approximately 3.5”
4. One coat of Perlite mixed with Calucm Lumnite ® Cacium Aluminate Cement approximately 1”

We are ready to set the cooking flooring.

Three questions:
1. When using fire brick as the ovens cooking floor, can we use a thin layer of: Calucm Lumnite ® Cacium Aluminate Cement for the under layer of the cooking floor?
2. When we constructed the Oven Stand. Was step 4 a mistake?
3. Could "Step 4" affect the overall performance of my pizza oven?

[Tscarborough]

Step 3 was a waste of fire brick, but other than that, no issues.

[Jed]

Microheli,

How big of an oven are you planning? A 4' X 4' base is a tad on the small size, depending on how you plan to construct, insulate, and finish the walls of your oven.

I might suggest your oven would perform better with more insulation directly under the cooking floor. The perlite / cement combination is not as efficient as the insulation boards, and with your configuration it looks like there is only 1 inch of insulation. (I think the layer of fire brick will do more to pull heat away from your cooking floor than add to the function of the oven).

My opinion is the oven will perform better if you replaced the existing layer of fire brick with perlite / cement insulation... and then install the cooking floor on that larger insulation layer.

Just an opinion!

Keep up the good work. Either way you will end up with an oven, that will be great fun to use and entertain visitors!


JED

[Microheli]

Thank you, Tscarborough & Jed for your great feedback. The Plan I am using are: Pompeii Oven™ Plans Version 2.0 with a 42" Interior.

At your service,

Microheli

[RTflorida]

You only mention a 1" layer of perlite insulation.....not nearly enough. The minimum recommended is 4" of perlite or vermiculite. Better yet, use the 2" FB board (or similar rigid refractory insulation boards).
I would also agree that your plan already has 4 1/2" of mass, without your hearth bricks; that is a HUGE heatsink. Even with good insulation (which you currently don't have), you are looking at a tremendous amount of wood consumption, long heat ups, and a tough time getting to and sustaining pizza temps. That first layer of firebricks is totally unnecessary - replace it with insulation.
Good luck, keep us posted.

RT

[Microheli]

RT, thanks for the advice. I will revisit the stand and remove the bricks.

[dmun]

Yes, a 42 inch oven will overhang a 48 inch base before you do any insulation or exterior structure. Read the plans again, and follow the insulation instructions exactly. Skimping on insulation either below or around your oven will result in an oven that won't cook well and will waste fuel in the process.

[DimTex]

I can only echo the comments of others, personally I cannot emphasize how cheating on insulation is false economy. Yes you get done faster, yes you save a little bit of money but it takes longer to heat up, holds heat for less time and consumes more firewood. Just not worth it. I spent the extra money, bought 3 boxes of the insulation blanket from FB ended up doing four layers of insulation on the dome and regret nothing. The stucco outside has never exceeded outside air temperature even when the inside is off the scale of my IR thermometer.

[Microheli]

Thanks, DimTex. Today I will start to remove step 3. I will insulate according to Plans. I will post pictures.

I am glad to hear all of this feedback from people that have created Pizza Ovens in the past.