Firebrick for the dome?

[Kurgan1234]

I am just about to start my first ever dome. I understand the need for firebricks. Is the use of firebrick completely necessary for the dome? Can I use a standard brick for the dome, and firebricks for the hearth? I live in San Francisco and the cheapest I have found these firebricks are over $5.00 a piece. I am planing a 42 inch cooking surface. That is a lot of bricks! I would appreciate any help I can get. Thank you in advance.

[UtahBeehiver]

I suggest you download the nominal cost (3 bucks) Pompeii e-plans from our Forno Bravo sponsor. There is a brick primer in the appendix talking about the pros and cons of different type of bricks. Typical 3 hole house bricks are not suitable for WFO oven. I have seen some builds made from solid clay bricks in the UK and New Zealand but I have not seen any info on how they have held up. Look at classifeds, Craiglist for surplus refractory bricks. 5 dollars a brick seems high for the US. Most builders are finding them in the $2 range. Check with refractory suppliers not just big box stores.

[Kurgan1234]

Thank you for the help. I will download the plans and review the information. 2 bucks a brick would be awesome!

[Gulf]

I agree with Russell . I've seen fire place stores charging outrageous prices for firebrick. They usually target home owners and DIYs. We need to source our bricks where contractors source theirs. A quick google search for "masonry supply San Francisco" shows a few hits. One of them lists full size fire bricks for $2.10.

[Kurgan1234]

Thanks for the heads up, I was searching for refractories and refractory bricks...

[Kurgan1234]

So after doing some research and speaking to the vendors they told me that their fire bricks are 58% silica I read on this website that it should be 38%. Is that just a minimum percentage in A specific range from 38 to say 70%? is that 58% acceptable for the inside of the woodfired oven, the floor and the dome?

the vendors I spoke with were HC Maddox and McNear.
any help would be appreciated, thanks for being patient with the new guy

[Gulf]

They do make a very soft sodium silicate refractory brick that you definitely do not want. However, it is the alumina content that we are concerned with in grading firebrick. Check back with your supplier and make sure that we are all on the same page. The Forno Bravo plans recommend a medium duty firebrick. But, the vast majority of the ovens made on this site are made from low duty standard fireplace firebrick simply, because of availability.

[Gulf]

Ask them for a material data sheet on their product. It should be available on line. That 58% silica content is about right. But, again it is the alumina content that we are most concerned with.

[Kurgan1234]

Thank you for the responses . I must admit this is a project that I have zero experience for , I don’t know much of anything about masonry or laying brick although I watch probably 100 videos and read 100 articles, I have the will, and I will try my best.

so the silica in the brick is not what’s important? I just wanted to make sure that the hearth and oven floor would not be so hot that it would burn the pizza as opposed to cooking it . I researched both companies for the bricks and was in able to Find any information regarding the aluminum or silica content. I was simply told by the vendor that the silica content ranges from 50% to 70% . So in a nutshell, will those bricks give me a good oven?

Thank you you in advance for youre patience with the new guy.

[Gulf]

I just wanted to make sure that the hearth and oven floor would not be so hot that it would burn the pizza as opposed to cooking it

.
For that reason low duty firebrick are what is mostly recommended for the hearth floor. That is the type firebrick that are mostly sold for use in fireplace boxes. The Forno Bravo plans recommend medium duty firebrick for the dome. However, low duty will work just fine.

.I was simply told by the vendor that the silica content ranges from 50% to 70% . So in a nutshell, will those bricks give me a good oven?

Sorry, I can't tell much about a firebrick from the silica content alone. Any chance that you can get back with the vendor about the "alumina" content?

[Kurgan1234]

Its a holiday weekend, so I sent an email. I probably won’t know till Tuesday. I wish they just post the data online. I just dig up some old bricks that are probably from the 30’s. My house was built in 1923. They are a deep red color and look like clay. Would those do? I will try to get picture up. Thanks for all you’re help.

[Kurgan1234]

I hope this works, won’t let me upload it because it is to big of A file.

[Gulf]

You will have to resize the photo in an image program. Or change the image size on your phone/camera and take another pic.

[UtahBeehiver]

Have you read the brick primer in the FB plans that I suggested? Only you can decide whether to use the old bricks. With no background on the old bricks it is a crap shoot. If you are going to invest the time, money and sweat equity in an WFO oven, bricks are probably not the place to cut corners.