just WINGING a 36

[pepe]

Hey WFO lovers! I am starting my build thread, for the giggles, my goal is to have a "light" bank friendly oven that will give me years of fun and happiness. I want to thank Yokosuka dweller and Gulf for the great advice and the forum in general for being such an encyclopedia. By the way, I have cero building/masonry experience but I love learning and DIY.

I am locating the oven on a second floor patio. My welder friend just finished the metal stand, and I am hoping to soon lay the cement hearth support.

I am thinking of using perlcrete for floor insulation and dome insulation. Still have not figured out if I need weep holes or how thick to make the hearth.

For the dome: Solid clay bricks 20 cm x 10 cm x 4 cm (100% extruded clay fired at 1000 c)
For the cooking floor I am not sure if I should spend 4 times more and have the firebricks, I have seen the clay bricks in action and find them very impressive.

Here is my table and my no skill layout! Any comments sure are EXTREMELY welcome!

[BanjoOgre]

Correct me if I'm wrong – but if weight is an issue is a pre-cast oven lighter than bricks and mortar? I'm sure there are far more experienced people well versed in this but I'd think a brick oven would weigh far more.

Also – if weight is an issue have you considered using Hebel for the hearth rather than pouring concrete. You can now get Hebel panels that are load rated to carry a very heavy load – they use them as load bearing for floor construction in multi story buildings here in Australia from my knowledge.

I know someone that has built 2 ovens now using the large Hebel floor panels instead of concrete, one is around 100mm internal, the other around 1500mm internal. Much lighter than concrete, and with a CalSil board underneath the floor bricks it'd be quite a bit lighter than concrete.

[UtahBeehiver]

Hebel has work for several of our Aussie friends as long as it is protected from high heat. As noted, a cast oven will be lighter than brick oven, ie 2" walls for a cast vs 4" wall on a brick oven. The problem with using a clay non refractory brick is the potential of spalling or break down after repeated firings and you will not know until the oven is done and then too late. Have there been ovens done with solid clays, yes(but it is crap shoot on the bricks working or not). There have been several nice cast ovens done lately with refractory brick floors.

PS these ovens are quite heavy, cast or brick, and some cross bracing on the stand legs should be considered.

[pepe]

Correct me if I'm wrong – but if weight is an issue is a pre-cast oven lighter than bricks and mortar? I'm sure there are far more experienced people well versed in this but I'd think a brick oven would weigh far more.

Also – if weight is an issue have you considered using Hebel for the hearth rather than pouring concrete. You can now get Hebel panels that are load rated to carry a very heavy load – they use them as load bearing for floor construction in multi story buildings here in Australia from my knowledge.

I know someone that has built 2 ovens now using the large Hebel floor panels instead of concrete, one is around 100mm internal, the other around 1500mm internal. Much lighter than concrete, and with a CalSil board underneath the floor bricks it'd be quite a bit lighter than concrete.

Weight is an issue mainly because I wanted to be able to move the oven around, the plan is soldiering wheels on the legs. My original design included HEBEL but I can only find block types and they do not seem to be reinforced, so I had to change my plan and use a concrete hearth (I thought they would crack if placed on the metal base as such). Originally I would have placed a Hebel stand and on top of that 1 or 2 inches of perlcrete for direct contact with bricks. I will call around, maybe I can find a solution for HEBEL as a hearth.

[pepe]

Hebel has work for several of our Aussie friends as long as it is protected from high heat. As noted, a cast oven will be lighter than brick oven, ie 2" walls for a cast vs 4" wall on a brick oven. The problem with using a clay non refractory brick is the potential of spalling or break down after repeated firings and you will not know until the oven is done and then too late. Have there been ovens done with solid clays, yes(but it is crap shoot on the bricks working or not). There have been several nice cast ovens done lately with refractory brick floors.

PS these ovens are quite heavy, cast or brick, and some cross bracing on the stand legs should be considered.

Well, I have been assured by the manufacturers that these bricks are 100% clay, fired at 1000c, that they don´t break or splint, and are commonly used regionally for an equivalent of a clay oven, bread ovens, smokers, firepits, and grills, so I think I will use them for the dome and keep a firebrick floor, does that sound ok?

[UtahBeehiver]

Your choice, I have already given my opinion.

[BanjoOgre]

I saw this video the other day that explains the spalling of clay bricks vs fire brick. It’s by a company here in Australia who produce fire bricks and oven kits so it is a subtle way to promote their products but it explains why fire bricks are best to use in a very easy to understand way.

https://youtu.be/PNC_17HdT3Y

[BanjoOgre]

And if you are looking for hebel this is the product I believe that is best used. It might not be available everywhere though so you might have a problem.

https://hebel.com.au/product/powerfloor/

[pepe]

Your choice, I have already given my opinion.

yes you did, thanks!

[pepe]

And if you are looking for hebel this is the product I believe that is best used. It might not be available everywhere though so you might have a problem.

https://hebel.com.au/product/powerfloor/

thanks a lot, I called around and found a contact at a local HEBEL factory. They sell LM´s, those are leftovers from big constructions so I probably have a good shot at finding a big reenforced panel!

[pepe]

I decided to go even cheaper hebel vs perlcrete since COVID-19 is slowing things down around. I also took UtahBeehiver advice and added some structural support to the legs, I am just not sure if I am placing the oven entrance correctly, maybe it is too much on the inside, I set it where the IT tool would touch/place the top key brick from my arch. Suggestions are welcome!

[pepe]

I just poured my perlcrete hearth, this is getting exiting!

[Yokosuka dweller]

On distance of front arch from center is a bit tricky. But you can use the IT or a piece of string. Basically if you have an adjustable IT, (or a piece of string) then you can extend it so that the vertical piece of the angle of the IT is exact on the external brick edge of a course. Knowing that distance you've checked from your dome course stays the same all the way up the hemisphere shape you can then use that same distance to check where the location of the brick that will sit on top of the arch should be, and that will give you the correct placement of the arch.

[UtahBeehiver]

Here is a pic on how to place the arch using an IT. It is done by the bottom of the floor because the dome arches moves away from the form at the top. Also you will need some relief on the bottom of the form or you will not get the form out once the arch is complete, The arch opening height should be about 63-65% of the dome height.

[pepe]

Thank you guys, I just finished my IT, it is UGLY but looks like it will work. In a couple of days of letting the perlcrete dry I will set it up and start the layout. Thanks for all the input.