Pompeii Oven over Wood-Fired BBQ

[metalarts]

Hello again all, In the last 7-10 days, I've been gathering all the materials I think that I'll need to get this project rolling. So far I have 32 Full-sized Cinderblock and 8 Half-blocks for the "Skeleton" or frame of the lower BBQ/ stand structure. I have also bought 298 4-1/2" x 9"x 2-12" thick Firebrick and 31 4-1/2 x 9" x 1-1/4" split Firebrick .

I'll be lining the lower structure with the Firebrick and starting the Chimney flue with full thickness Firebricks. The chimney flue will eventually be split( 1-1/2" ) firebricks on the inside, overlaid with stone on the outside. The upper part of the chimney will be 2 clay flues 8"x 12" side by side with firebrick between them for strength and structure.

The Cinderblocks will be mortared with refractive mortar, Type S 50% and Fireclay 50%. inside the hollows, and drilled into the patio below which already has 12" thick footings, I'll reinforce with #4 rebar and then pour the hollows full of concrete.

Got to get dinner going, I'll post up some initial dry layout pics either later tonight or tomorrow. Any advice or comments are quite welcome, gents. Cheers from the Colonies

[bookemdanno]

sounds interesting!
be nice to see some sketches...

[metalarts]

Here are a few pics of some of the dry layout. Please note that very few of the Firebrick are actually where they will be eventually. I was trying to get a count on how many that I may need total for the project. None of the Firebrick that are on top of the Cinderblocks will be there for example, and the flue-lining split bricks will actually be below the clay flue liners that they are sitting on in these photos. Also, the front course and those outside the front of the opening are just there temporarily.

Once I drill the patio for #4 Rebar in each cinderblock opening, I'll lay the inner structure of cinderbolck and then fill the openings in the cinderblock with concrete aggregate. After that, I'll be setting up the forms and rebar grid for my structural 3" top to the firebox. This will be poured of Fondue, as it will eventually be having fires in it. Of course, the lower section( BBQ Section), will be completely lined with the Firebrick on all 4 sides, top and bottom. I will likely be making a running bond pattern on the side walls( correct terminology?). I am also playing with the idea of buying a few more of the Black firebrick and incorporating them into the pattern somehow.







I am no expert Mason by any stretch of the imagination, but I did build the 700 sq ft Stamped Concrete patio seen in the photos about 9 years ago with a few of my mates. The area under the Fireplace-BBQ has 12" deep footings and copious reinforcements ( 5 ways or more) of 1/2" rebar. I've been intending on building this structure from the beginning. The only thing that has changed is the addition of a Pompeii Oven on top of the lower structure. I think that we are more excited about the Bread/ Pizza Oven than we are with the Fireplace/ BBQ itself.

All insights and advice are welcomed. Regards, MetalArts in Oregon, U.S.A.

[bookemdanno]

Wowzers, this is a new one!

All i can comment at the moment, is maybe you'd benefit from some sort of insulation underneath the "firebox" firebricks, and between the Cinderblock and the side walls of the "firebox", or you'll be trying to heat up all that concrete patio too. It'll suck the heat from where you want it.
Vermiculite Concrete could be the solution. For instance...
Build up your cinderblock, but potentially around 8" wider internally. Then cast 4" of Vermiculite concrete as a floor to the firebox. Build up your firebox floor, end and side walls leaving a 4" gap to the cinderellas. Then back fill these side voids with more Vermiculite concrete. This should give you a fully insulated "floating" firebox.
You may find that there are better things, Calsil board for instance. It's your choice, but i'd not leave out the insulation, or you'll take ages to heat up what will be quite a beast, by the look of it!
Look up Barrel Vault Ovens, as i think that the firebox/bbq could be build in a similar manner.

This'll be an interesting build...

So, is the BBQ going to heat the Pizza Oven, or just be a dual purpose stand?

[metalarts]

The BBQ portion shown will be for cooking and enjoyment of fires such as a regular fireplace would work.

On top of this will be built a standard Pompeii style WFO such as the ones shown in this Forum. On top of the structural 3" slab will be either a 5" Vermicrete layer or Thermolite Blocks if I could ever find them on this side of the pond. When I enquire about them here, people look at me with a glassy-eyed stare as if I've made them up. In any case over this insulation layer, I'll build a Pompeii Wood-Fired oven such as Terry's second build for his boss in the archive.

The Pompeii will be 32" in circumference inside, about 16-18" tall inside, and the chimney in the front like those shown at this Forum.

The portion that I have shown pics of will have it's chimneys at the rear, and will not share the heat souce at all with the WFO above it.

My Girlfriend/ Partner of 22 years wants both an outdoor fireplace/ BBQ as well as a Bread oven/ Pizza Oven in the same area of the patio. She is an excellent partner, and is well worth getting what she'd like.....

EDIT: Along the lines of this, but with the bottom BBQ closed at the rear.

[metalarts]

I picked up (13) 4"x 8"x 16" Cinderblocks today for the chimney structure. As stated earlier, it will be lined with 1-1/2" thick Firebricks, leading up to a 8"x 12" Clay Flue and then a Stainless Steel Spark Arrestor/ Chimney Cap. I talked to my mate who helped me on my Patio build 9 years ago. he is a Pool and Patio professional, and does some work with fired appliances as well. He agreed that the structural 3" slab above the BBQ Firebox and below the 5" Vermicrete insulation layer should be made of Fondue. Nice to have this confirmation from a few people in the industry, although I give as much weight to the advice on this Forum as I do from any other source that I have found. I have a Hammer-Drill to drill the stamped-concrete patio for the rebar. Mt friend confirmed that it would be best to fasten the rebar into the patio with epoxy. He will have some epoxy-coate rebar available for me by this coming Friday. I'll have the holes drilled by then, and cleaned out thoroughly( very important step). I'll epoxy the rebar in, and then I'll lay all the cinderblock base for the structure hopefully Friday the 5th.