Advice on buying firebricks

[JDERRICK]

Hi, I'm totally new to brick ovens, I am gathering supplies right now and then I'm just going to jump into it and get started. It seems like 200 Firebricks will be good (I'm hoping) to make the firing chamber. Anyways, I found this guy who will sell me 4x9 firebricks for $.63 a brick. I'm not sure, but I thought this was a really good deal. Should I just buy like 400 of them instead of 200. Is it beneficial or possible to do a double layer of fire brick? Any advice is helpful. Thank you.

[mrchipster]

Re: Advice on buying firebricks

Hi, I'm totally new to brick ovens, I am gathering supplies right now and then I'm just going to jump into it and get started. It seems like 200 Firebricks will be good (I'm hoping) to make the firing chamber. Anyways, I found this guy who will sell me 4x9 firebricks for $.63 a brick. I'm not sure, but I thought this was a really good deal. Should I just buy like 400 of them instead of 200. Is it beneficial or possible to do a double layer of fire brick? Any advice is helpful. Thank you.

4x9x??? if these are splits you will need more bricks. The floor should be 2.5 thick or thicker to retain enough heat. The dome will be about 4 inches thick if you use half bricks and that is thick enough if well insulated.

The thicker you make your dome and floor the more wood it will take to heat saturate the structure. I get great heat retention but I am very well insulated (floor and dome) and used two heat breaks and a heavily insulated door.

if you are looking at baking bread regularly a thicker dome and floor may be beneficial. but if you are doing pizza and general cooking then standard practice should apply.

my two cents

Chip

[JDERRICK]

Re: Advice on buying firebricks

The guy delivered 200 today, they are 9x4.5x2.5", I payed $125 for them. Is that a good deal? Chip, my wife does enjoy baking bread, so maybe I should use more fire bricks. Is it only additional wood ie. heat intensity to reach necessary heat saturation or is it a matter of time? Would it take a significantly longer time to preheat if I made the dome say 9" and the floor 5" instead of 2.5" and 4"?

[irelande5]

Re: Advice on buying firebricks

Hi JD,
That sounds awefully cheap, maybe too good to be true. I shopped around a lot, and lowest I found in Ohio was 1.40 for low duty (2.5 x 4 x 9). I would make sure they are true low duty fire bricks with documentation/manufacture info to back it up. An oven is a lot of work, and takes considerable amount of money/time/research to complete, bricks being the foundation you want to make sure you have a quality brick that can withstand thermal cycling/temps. Good luck Pat

[mrchipster]

Re: Advice on buying firebricks

if they are medium duty bricks and you want to add some thermal mass lay the floor bricks so they are 4.5 thick on edge as it were. make sure you have at least 4 inches of insulation below the entire oven floor and dome, i used 2.5 vermicrete and 2 inches fb board, and insulate the dome with at least 6 inches of insulation. 2 inches of ceramic blanket and the rest vermiculite or perlite. a 4 inch brick dome thickness should be satisfactory unless you are planning to do commercial baking.

i have almost a foot of perlite over the top of my oven but I had plenty of space and it is cheap.

Chip.

[JDERRICK]

Re: Advice on buying firebricks

I had to look up what the duty rating was but as I understand it, the duty rating (low,med,high) has to do with the aluminum content and the higher the duty, the higher the temperature. Is that correct? I'm not sure how to tell if the bricks I got are any good, they say "MO FLINT" on them. I did a google search for mo flint and found this Brick Names (mine is the 14th down from the top)

Chip- I guess I'm kind of slow, what do you mean "floor bricks so they are 4.5 thick on edge as it were". What orientation of the brick are you describing?

[mrchipster]

Re: Advice on buying firebricks

for greater floor thickness you can stand the bricks on their sides in a herringbone pattern and get a greater thickness (mass) in the floor.

normaly the bricks would be placed so they created the thinest profile in your case 2.5 floor thickness, but if you want to have greater mass in the floor you could place them on their sides giving a 4.5 thick floor.

I do not know anything about that particular brick.

Chip

[JDERRICK]

Re: Advice on buying firebricks

Ahh, I see. Thank you.

[irelande5]

Re: Advice on buying firebricks

Hi JD, yes the higher the duty higher the alumina content, higher rating. Most folks use light duty bricks as they are usually more common than med duty, forno bravo recommends med duty. If you downloaded the plans for oven, check out the brick primer on end of manual, really explains it well. Pat