1inch Firebrick

[Taahir]

Hi,

Based in South Africa. Standard size firebrick is extremely expensive here (equivalent $3). However, 1inch thick firebrick is not too bad - $1 each. Planning on building a low dome barrel style.

So I was thinking. What if I built the floor and dome out of the 1inch firebrick, and then built a structure under the floor and around the dome out of solid clay overburnt bricks. Total inches will be 4inches in total floor and dome.

Could this work? Everything else will be in place (vermicrete hearth, insulation blanket, etc).

Works out to around $50 more than doing standard fire brick floor, and clay brick dome, or around $400 dollars cheaper than complete standard fire brick.

[GianniFocaccia]

Re: 1inch Firebrick

There is a long history of ovens in pompeii constructed with 1" bricks. A few builders here have made the same inquiry as yours, but I am aware of only one builder who used splits, and it was for his entryway, not the dome.

Personally, I think using splits makes for a very handsome and unique oven,

I am not aware of a barrel vault being made with splits, but there is no reason it wouldn't work. It will just take more time and mortar to construct than using standard firebrick.

[Tscarborough]

Re: 1inch Firebrick

Mine is made with splits, also split longways in 2 layers. Just make sure you get a full bed of mortar between layers with no air gaps.

[Taahir]

Re: 1inch Firebrick

There is a long history of ovens in pompeii constructed with 1" bricks. A few builders here have made the same inquiry as yours, but I am aware of only one builder who used splits, and it was for his entryway, not the dome.

Personally, I think using splits makes for a very handsome and unique oven,

I am not aware of a barrel vault being made with splits, but there is no reason it wouldn't work. It will just take more time and mortar to construct than using standard firebrick.

I am planning on using the 1inch fire bricks as sailors for the walls, and strechers for the dome. then directly over that the overburnt clay bricks. The clay bricks as equivelent $0.28, so quite cheap. Question though, will the added weight of the clay bricks on top of the fire bricks be an issue? Especially as I am doing a low domed barrel? or because the fire bricks and clay bricks are mortared together they will hold up well? Worried that 4inch is too much thermal mass and will take long to heat up, but I'm hoping that the combination of the low dome + smaller dimensions (around 90X60) will compensate and allow a faster heat up time (fires are kept at the back of Barrel ovens, correct?)

[Taahir]

Re: 1inch Firebrick

Mine is made with splits, also split longways in 2 layers. Just make sure you get a full bed of mortar between layers with no air gaps.

I am planning something very similar yes. Was originally just going to use only the overburnt bricks, but all the posts here about spalling is a bit scary.

[Taahir]

Re: 1inch Firebrick

Mine is made with splits, also split longways in 2 layers. Just make sure you get a full bed of mortar between layers with no air gaps.

All things being equal, can a low domed barrel oven reach neapolitan style temperatures in decent times (1.5 hours), or is that being unrealistic? Assuming I go with the splits, keep the size small (90X60 or 100X70), and have sufficient insulation and a decently sized doorway and chimney?

I know a low domed pompei style would suit better for that, but for a first timer, the barrel seems easier to build, and more well rounded if I wanted to do BBQs, slow cooked food etc etc.

[GianniFocaccia]

Re: 1inch Firebrick

Oops! I completely forgot about TScar's excellent oven. Tom is the person to ask regarding loading of his Guastavino-style vault.

I would not concern myself with heat-up times unless fuel is really scarce. There won't be much of a difference in firing time between the two sizes you listed. If all you're doing is pizza, you can get 'decent pizza' temps from 1.5hrs, but the more you load your oven, the better the pizza gets.

Don't let your inexperience scare you. There are countless first-timers here that have constructed beautiful, excellent-performing pompeii ovens. There are plenty of folks here willing to answer your questions.

[Taahir]

Re: 1inch Firebrick

Oops! I completely forgot about TScar's excellent oven. Tom is the person to ask regarding loading of his Guastavino-style vault.

I would not concern myself with heat-up times unless fuel is really scarce. There won't be much of a difference in firing time between the two sizes you listed. If all you're doing is pizza, you can get 'decent pizza' temps from 1.5hrs, but the more you load your oven, the better the pizza gets.

Don't let your inexperience scare you. There are countless first-timers here that have constructed beautiful, excellent-performing pompeii ovens. There are plenty of folks here willing to answer your questions.

Thanks for the vote of confidence. To be honest fuel is not really scarce really, and am planning for pizza/BBQ/food/bread. Us South Africans "braai" aka BBQ every weekend, especially with the awesome summer we having. 26degree heat, light breeze, no clouds....

Busy building a boundary wall, double garage, entertainment area addition to my house anyway, so I figured might as well use what materials I am ordering anyways, and finally take the pizza plunge.

Planning on taking my time on this, maybe 2 months. Digging tomorrow for the foundation. Lets hope this goes well

[Taahir]

Re: 1inch Firebrick

Tscarborough, just finished your thread - really inspiring!! Tell me, you mentioned there your next build would be more square, and low domed. Any particular reason? Also, do you think there can be any benefit from having a rounded back and front (better licking of fire on to the ceiling?) or will the heat just radiate throughout the oven, regardless of the straight back and front. Also, I noticed you cooked your pizza on the side.... any particular reason vs keeping the fire at the back and cooking it in front?

[Tscarborough]

Re: 1inch Firebrick

More square because I make 16" pizzas, and that puts the edge almost into the fire in a 22" wide oven. Rounding the ends is probably not worth the effort of making them work.

I used to fire my oven in an hour and a half, but I normally fire it for around 4 hours now, it is just much easier to control the temps when it get heat soaked.

[Taahir]

Re: 1inch Firebrick

More square because I make 16" pizzas, and that puts the edge almost into the fire in a 22" wide oven. Rounding the ends is probably not worth the effort of making them work.

I used to fire my oven in an hour and a half, but I normally fire it for around 4 hours now, it is just much easier to control the temps when it get heat soaked.

4 hours of blazing fire, or one log at a time to keep it steady?

[Tscarborough]

Re: 1inch Firebrick

4 hours of 3-4 5x16 logs. Not a big fire, but a hot one.

Heating fire

Cooking fire

[Taahir]

Re: 1inch Firebrick

This is what I am thinking of so far, showing the design and the 1inch firebrick and 3inch overburnt clay bricks layers

Wasnt sure on where the vent should be. I was hoping if it starts "higher" than the door, then the smoke will escape easier, allowing the doorway to be only for fresh incomming air.

[Tscarborough]

Re: 1inch Firebrick

Normally the vent is outside of the oven. There is a ratio drawn from the study of old and new ovens that says that an opening height that is 62-64% of the oven ceiling will provide the most heat retention and best draw.

[Taahir]

Re: 1inch Firebrick

Normally the vent is outside of the oven. There is a ratio drawn from the study of old and new ovens that says that an opening height that is 62-64% of the oven ceiling will provide the most heat retention and best draw.

Hmmm okay. I am starting to think I am aiming to low, as a 23cm height isn't much

Also, if we say 62-63% for door height vs inside height, is the any specific ratio for door width vs inside width (or is this just a matter of convenience?)