Oven Floor question

[EP-1550]

Folks,
this is my first posting here on the site...
I'm a "foodie", and pizza making happens to be one of my passions.
Although I've been on this site many times, just now I noticed about this forum.

In any case, although I know a lot about cooking, i'm not very handy (construction guy) and need some advice.

I have owned many Pizza ovens in the past, generally hand made by professionals when i lived down in Brazil. Although they took a long time to get hot, they held the temps for a long time and the Pizza's were amazing.

2 years ago (here in the US) I bought a modular oven, and although i have been happy with the overall results, I feel like the floor (made of 4 large refractory pieces) might not hold the heat as well as the individual bricks that I had in my past ovens.

The result, is that sometimes the dough, although gets cooked, does not show the natural cooked spots at the bottom.

Now the question:

I was thinking about resurfacing the floor of my oven with fire bricks but do not know witch ones to buy. I have a very good contractor to do the work for me...just need some advice.

Thanks,

[Paul in Rockwall TX]

I used a basic firebrick, I can send you the specs (I have an MSDS and data sheet).

they come in both full brick 4-1/2 x 9 x 2-1/2, and what are called splits. the splits are half as thick, 1-1/4 and might be suited for your purpose.

I would attach a document, but ther is not an attachment option.

[Lburou]

Originally Posted by EP-1550

Folks,
this is my first posting here on the site...
I'm a "foodie", and pizza making happens to be one of my passions.
Although I've been on this site many times, just now I noticed about this forum.

In any case, although I know a lot about cooking, i'm not very handy (construction guy) and need some advice.

I have owned many Pizza ovens in the past, generally hand made by professionals when i lived down in Brazil. Although they took a long time to get hot, they held the temps for a long time and the Pizza's were amazing.

2 years ago (here in the US) I bought a modular oven, and although i have been happy with the overall results, I feel like the floor (made of 4 large refractory pieces) might not hold the heat as well as the individual bricks that I had in my past ovens.

The result, is that sometimes the dough, although gets cooked, does not show the natural cooked spots at the bottom.

Now the question:

I was thinking about resurfacing the floor of my oven with fire bricks but do not know witch ones to buy. I have a very good contractor to do the work for me...just need some advice.

Thanks,

Welcome!

Do you have an idea of your current floor temperatures?
Being an experienced user of pizza ovens, you have probably already considered heating your oven to a hotter cooking range to get the crust you prefer.....yes?
When you replace your oven floor, you'll have to be careful to keep good air/gas circulation, facilitated by the oven door/dome heigth ratio (63% is optimum).
Just some thoughts

[Karangi Dude]

Hey EP-1550,

What insulation is under the floor? what does it all sit on concrete or metal base?
You could be loosing heat through the floor to the base. If it is not an insulation problem then perhaps you could just add more mass to the existing floor by placing fire brick tiles about 2" thick on top. This will of course reduce the height of the opening a bit, but should not create any problems.

Cheers Doug

[EP-1550]

Thanks for the feedback!
As far as the insulation, i dont remember what was used.
the oven base was made with uniblocks to match the rest of the outdoor kitchen space, sand and sheet rock were used to fill the hole and then addttional uniblocks were aplied on top to create the flat surface of the oven...the oven was built on top of that base.

As far as creating a new floor, I was thinking about Doug's idea...to resurface the floor with Firebricks. I also don't mind making the floor thicker since i was also planing to reduce the size of the door.

As far as getting Firebricks, is there a brand that i should look for? I live in Michigan, do they sell them at Home Depot or Lowes?
Lastly, what do i include below the firebricks to hold them in place? clay mortar?

Thanks guys

[dmun]

As to the brick question, the ordinary firebricks that are sold at a brickyard or masonry supply (not one of the big box stores) are low duty firebricks, and are the ones you want. There are medium and high duty bricks available at refractory suppliers, and these are generally considered overkill at our operating temperatures. Depending on what your insulation layer is, the floor bricks are either laid flat, without mortar, on the insulation, or if the insulating surface is rough, a layer of sand and fireclay is laid down as a leveling medium. Floor bricks aren't mortared in place.

Now, this is very important. I suspect that your floor is not giving you the results you want, not because of the composition of the floor sectors (which in many cases is the same material as firebricks) but there is inadequate insulation underneath it. Between your masonry support layer and your oven floor there should either be two inches of refractory insulation board (which is a dense, fibrous, usually buff colored material) or four inches of vermiculite concrete (This is a grey, cork like, crumbly layer). Without proper insulation layer (or damp insulation, which is another topic) your floor won't give you the leoparding that you want.

[EP-1550]

Thanks for the information...that is very helpful.
So, if i add the firebricks on top of my exisiting floor, will I have better results?

Thanks!

[stonylake]

so, where in Michigan? there is a great supplier in GR, Industrial Firebrick on Ann Street. you can get larger brick there for your floor if you don't want as many seams. they also have several thicknesses of ceramic insulation and sell it by the piece

[EP-1550]

I'm actually in Bloomfield Hills and I did find a supplier in Novi.
The guy actually has an oven himself...not very common in this part of the State, but he seems to know his trade.

I'm going to swing by on Tuesday.

His recomendation was to use just a little sand on top of the exisiting floor and dry-fit the bricks inside the over. Easier to remove if necessary...

Thanks everyone for the great feedback and ideas.

I can't wait to fire up the oven for the 2011 season.

[dmun]

So, if i add the firebricks on top of my exisiting floor, will I have better results?

You'll add thermal mass, which may or not be good depending on what's there now. On the other hand, you won't see exactly what you have in insulation underneath, which may be more important than the exact composition and thickness of your cooking floor.

His recomendation was to use just a little sand on top of the exisiting floor and dry-fit the bricks inside the over. Easier to remove if necessary...

Plain sand is a little shifty for a leveling medium. We mix it half and half with fireclay, which is more likely to stay put.